Meet the Microbiologist

Dev Mittar, Ph.D., Scientific Director of the ASM Health Scientific Unit discusses the use of metagenomic next generation sequencing to develop agnostic diagnostic technology, giving scientists and clinicians alike, a tool to diagnose any infectious disease with one single test. He also discusses how the ASM Health Unit is empowering scientists and leveraging microbial science innovations to address critical global health challenges and improve lives worldwide. Ashley's Biggest Takeaways The Division of Research, Innovation and Ventures is a small entrepreneurial arm of BARDA that takes on early-stage projects with high potential of turning into medical countermeasures. Prior to his role as Scientific Director for ASM Health, Mittar worked as a health scientist and program officer at DRIVe, where he focused on advancing high-impact science. He is particularly passionate about his work to develop agnostic diagnostics—a single test that uses metagenomic next generation sequencing to identify any pathogen from 1 clinical sample. Mittar discusses applications for this technology in surveillance (pandemic preparedness), variant detection, AMR and clinical settings (diagnosing complicated infections where etiology is not clearly defined). He also shares how a recent bout with illness emphasized the value and potential of this technology to save money, time, pain and suffering of the patient. Agnostic diagnostics can also help prevent the overuse/misuse of antibiotics, which are key factors in the spread of antimicrobial resistance. Furthermore, when this technology is coupled with the use of metatranscriptomics, it can provide information about the patient's immune profile that can be helpful in developing personalized treatment strategies, as opposed to a one-size-fits-all approach. ASM is organizing around 3 scientific units, ASM Health, ASM Mechanism Discovery and ASM Applied and Environmental Microbiology. These units will empower researchers and scientists to use science make a difference in the world and provide a forum for them to come together to shape the future of the field. Links for This Episode Learn More About ASM's Scientific Units. Join the Conversation on ASM Connect, our online community platform. Browse Volunteer Opportunities. Become an ASM Member. Register for ASM Microbe 2025.

Episode Summary Afreenish Amir, Ph.D., Antimicrobial Resistance (AMR) Project Director at the National Institute of Health in Pakistan, highlights significant increases in extensively drug-resistant typhoid and cholera cases in Pakistan and discusses local factors driving AMR in Asia. She describes the development and implementation of a National Action Plan to combat AMR in a developing country, emphasizing the importance of rational antimicrobial use, surveillance and infection control practice. Ashley's Biggest Takeaways AMR is a global and One Health issue. Pakistan has a huge disease burden of AMR. Contributing factors include, but are not limited to, overcrowding, lack of infection control practices, poor waste management practices and over-the-counter prescription practices. Promoting the rational use of antimicrobials is imperative at all levels—from tertiary care to primary care practitioners. Typhoid and cholera are high-burden infections in Pakistan, with typhoid being a year-round issue and cholera being seasonal. A holistic approach, involving various sectors and disciplines, is necessary in order to address the global AMR threat. Amir highlights the need for better communication and collaboration to bridge gaps and build trust between different organizations. Featured Quotes: I've been working at the National Institutes of Health for the last 7 years now. So, I've been engaged in the development and the implementation of the national action plan on AMR, and that gave me the opportunity to explore the work in the field of antimicrobial resistance. Reality of AMR in Pakistan [Pakistan] is an LMIC, and we have a huge disease burden of antimicrobial resistance in the country right now. A few years back, there was a situational analysis conducted, and that has shown that there is presence of a large number of resistant pathogens within the country. And National Institutes of Health, they have started a very standardized surveillance program based upon the global antimicrobial use and surveillance system back in 2017. And [those datasets have] generated good evidence about the basic statistics of AMR within the country. So, for example, if I talk about the extensively drug-resistant typhoid, typhoid is very much prevalent in the country. Our data shows that in 2017 there were 18% MDR typhoid cases through the surveillance data. And in 2021 it was like 60%. So that has shown that how the resistance has increased a lot. A number of challenges are associated with this kind of a thing, overcrowded hospitals, poor infection prevention and control (IPC) measures. So, there is AMR within the country—there's a huge burden—and we are trying to look for the better solutions.  Local Factors Driving AMR Bacteria, they do not know the borders. We have a close connection with the other Asian countries, and we have a long border connected with the 2 big countries, which are Afghanistan and India and Bangladesh and China. So, we see that it's not limited to 1 area. It's not regional. It's also a history of travel. When the people travel from one area to the other, they carry the pathogen as a colonizer or as a carrier, and they can infect [other] people. So, it's really connected, and it's really alarming as well. You never know how the disease is transmitted, and we have the biggest example of COVID—how things have spread from 1 country to the other, and how it has resulted in a massive pandemic. AMR is similar. We have seen that it's not limited to 1 region. We are part of this global community, and we are contributing somehow to the problem. First, I'll talk about the health care infrastructure. We do have the capacities in the hospitals, but still, there's a huge population. Pakistan is a thickly populated country. It's a population of around 241 million. And with the increasing population, we see that the infrastructure has not developed this much. So now the existing hospitals are overcrowded, and this has led to poor infection control practices within the hospitals. The staff is not there. In fact, ID consultants are not available in all the hospitals. Infection control nurses are not available in all the hospitals. So, this is one of the main areas that we see, that there is a big challenge. The other thing that can contribute is the poor waste management practices. Some of the hospitals—private and public sectors—they are following the waste management guidelines—even the laboratories. But many of the hospitals are not following the guidelines. And you know that AMR is under one health. So, whatever waste comes from the hospital eventually goes to the environment, and then from there to the animal sector and to the human sector. [Another big] problem that we are seeing is the over-the-counter prescription of antimicrobials. There is no regulation available in the country right now to control the over-the-counter prescription of antibiotics. They are easily available. People are taking the antibiotics without a prescription from the doctors, and the pharmacist is giving the patients any kind of medicine. And either it is effective/not effective, it's a falsified, low-quality antibiotic for how long in duration antibiotic should be taken. So, there are multiple of things or reasons that we see behind this issue of AMR. Rational Use of Antimicrobials It is a complex process how we manage this thing, but what we are closely looking at in the country right now is that we promote the rational use of antimicrobials at all levels—not only at the tertiary care levels, but also at the general practitioner level. They are the first point of contact for the patients, with the doctors, with the clinicians. So, at this point, I think the empirical treatment needs to be defined, and they need to understand the importance of this, their local antibiograms, what are the local trends? What are the patterns? And they need to prescribe according to those patterns. And very recently, the AWaRE classification of WHO, that is a big, big support in identifying the rational use of antimicrobials—Access, Watch and Reserve list—that should be propagated and that should be understood by all the general practitioners. And again, I must say that it's all connected with the regulations. There should be close monitoring of all the antibiotic prescriptions, and that can help to control the issue of AMR. National Action Plan on AMR So, when I joined NIH, the National Election plan had already been developed. It was back in 2017, and we have a good senior hierarchy who has been working on it very closely for a long period of time. So, the Global Action Plan on AMR, that has been our guiding document for the development of the national action plan on AMR, and we are following the 5 strategic objectives proposed in the global action plan. The five areas included: The promotion of advocacy and awareness in the community and health care professionals. To generate evidence through the data, through the surveillance systems. Generation of support toward infection prevention and control services IPC. Promoting the use of antimicrobials both in the human sector and the animal sector, but under the concept of stewardship, antimicrobial consumption and utilization. Invest in the research and vaccine and development. So, these are some of the guiding principles for us to develop the National Action Plan, and it has already been developed. And it's a very comprehensive approach, I must say. And our institute has started working on it, basically towards recreating awareness and advocacy. And we have been successful in creating advocacy and awareness at a mass level. Surveillance We have a network of Sentinel surveillance laboratories engaged with us, and they are sharing the data with NIH on a regular basis, and this is helping NIH to understand the basic trends on AMR and what is happening. And eventually we plan to go towards this case-based surveillance as well, but this is definitely going to take some time because to make people understand the importance of surveillance, this is the first thing. And very recently, the Institute and country has started working towards the hospital acquired infection surveillance as well. So, this is a much-needed approach, because the lab and the hospital go hand in hand, like whatever is happening in the lab, they eventually reach the patients who are in the hospitals. Wastewater surveillance is the key. You are very right. Our institute has done some of the work toward typhoid and cholera wastewater surveillance, and we were trying to identify the sources where we are getting these kinds of pathogens. These are all enteric pathogens. They are the key source for the infection. And for the wastewater surveillance mechanism, we can say that we have to engage multiple stakeholders in this development process. It's not only the laboratory people at NIH, but we need to have a good epidemiologist. We need to have all the water agencies, like the public health engineering departments, the PCRWR, the environmental protection agencies who are working with all these wastewater sites. So, we need to connect with them to make a good platform and to make this program in a more robust fashion. Pathogens and Disease Burdon For cholera and typhoid within Pakistan, I must say these are the high burden infections or diseases that we are seeing. For typhoid, the burden is quite high. We have seen a transition from the multidrug-resistant pathogens to the extensively drug-resistant pathogens, which now we are left with only azithromycin and the carbapenems. So, the burden is high. And when we talk about cholera, it is present in the country, but many of the times it is seasonal. It comes in during the time of the small zone rains and during the time of floods. So, every year, during this time, there are certain outbreaks that we have seen in different areas of the country. So, both diseases are there, but typhoid is like all year long—we see number of cases coming up—and for cholera, it's mainly seasonal. Capacity Building and ASM's Global Public Health Programs Capacity building is a key to everything, I must say, [whether] you talk about the training or development of materials. I've been engaged with ASM for quite some time. I worked to develop a [One Health] poster in the local language to create awareness about zoonotic diseases. So, we have targeted the 6 zoonotic diseases, including the anthrax, including the Crimean-Congo hemorrhagic fever and influenza. And we have generated a very user-friendly kind of layout in the local language, trying to teach people about the source of transmission. What are the routes of transmission, if we talk about the CCHF? And then how this can be prevented. So, this was one approach. And then I was engaged with the development of the Learnamr.com. This is online platform with 15 different e-modules within it, and we have covered different aspects—talking about the basic bacteriology toward the advanced, standardized methods, and we have talked about the national and global strategies [to combat] AMR, One Health aspects of AMR, vaccines. So, it's a huge platform, and I'm really thankful to ASM for supporting the program for development. And it's an online module. I have seen that there are around more than 500 subscribers to this program right now, and people are learning, and they are giving good feedback to the program as well. We keep on improving ourselves, but the good thing is that people are learning, and they are able to understand the basic concepts on AMR. Links for This Episode: Experts Discuss One Health in Pakistan: Biosafety Education Inside and Outside the Lab.  Explore ASM's Global Public Health Programs.  Download poster about zoonotic disease in English or Urdu.  Progress on the national action plan of Pakistan on antimicrobial resistance (AMR): A narrative review and the implications.  Global diversity and antimicrobial resistance of typhoid fever pathogens: insights from 13,000 Salmonella Typhi genomes.  Wastewater based environmental surveillance of toxigenic Vibrio cholerae in Pakistan.  Point Prevalence Survey of Antimicrobial Use in Selected Tertiary Care Hospitals of Pakistan Using WHO Methodology: Results and Inferences.  Overcoming the challenges of antimicrobial resistance in developing countries.  Take the MTM listener survey! 

Manuel Martinez Garcia, Ph.D., a professor of microbiology in the Physiology, Genetics and Microbiology Department at the University of Alicante in Spain, paints a picture of what microbial life looked like thousands of years ago by analyzing microbial genomic signatures within ice cores collected from the Antarctic ice shelves in the 1990s.  Links for the Episode  New avenues for potentially seeking microbial responses to climate change beneath Antarctic ice shelves – mSphere paper.  Viruses under the Antarctic Ice Shelf are active and potentially involved in global nutrient cycles – Nature communications article.  Manuel Martinez Garcia's Lab website.  How stable is the West Antarctic Ice Shelf? – Press Release from Alfred Wegener Institute. Take the MTM listener survey! Watch this episode: https://youtu.be/CHCMO74_gIY Ashley's Biggest Takeaways There is a unique habitat beneath Antarctic ice shelves, where microbes live without light and rely on unusual energy sources.  Ice cores from these Antarctic ice shelves can preserve fossilized genomic records of microbial life from long ago.  Comparing past and present samples can help us understand how microbial life is responding to environmental stressors, like temperature changes and acidification, over time. It can also provide key insights to changes in biodiversity. Featured Quotes:  Motivation for the Research Ice shelves are like massive floating ice that are in Antarctica, mainly. They can be as big as, for example, France, the country. So, they are super big—they are enormous. And they can be as thick as, let's say, 1000 meters. So, this is a massive [piece of] ice that we have in our planet.   And beneath that massive ice, we can have a very peculiar and a special habitat in which microbes live without light. They have to manage, to thrive and reproduce, without using a standard energy like we have on the surface of the sea or in the forest, where we have light that is driving and providing the energy for the ecosystem. But in this case, these ecosystems are totally different.  [The ice shelves] are deep and interconnected. Basically, there are different oceanic currents, for example, there is one Circumpolar Current that surrounds Antarctica, and there are also other currents that basically go from the bottom to the surface, moving, you know, all the water masses.  The interesting part of this story is that every single second in our lives, this sea that is beneath the platform, the ice shelf, is frozen over and over, and then we have different layers of antiquity that preserve the microbes that are living in the ocean. So, for example, let's say, 1000 years ago, the sea water was frozen, and then we can find a layer beneath the Antarctica ice shelf, where these microbes are preserved and frozen. Basically, it's like a record—a library of microbes, fossil records of microbes—from the past ocean, from 1000 years ago until present, more or less.  And then we can go to these records, to these layers of frozen sea water, and pick these samples to somehow recover the genetic material of the microbes that were preserved and frozen 1000 years ago or 500 years ago, in the way that we can somehow reconstruct or build the genetic story of the microbes from the past, for example, pre-industrial revolution to present.  We need to think that microbes sustain the rest of the food web. So, they sustain of the rest of life in the ocean. They provide carbon for the rest of organisms, the fishes, whales [and other] big animals that we have in our oceans. And if the microbes are responding in a way that is not satisfactory, or in the way that we think can maintain the food web, this is kind of scary. And this is what we are trying to do: we are trying to go back to the past and see how the microbes are changing [genetically].  Sample Collection We didn't collect the samples. [They were collected] back in the 90s, so, 40 years ago, by a German group led by the Alfred Wegener Institute, which is probably one of the most famous polar institutes in the world. They, basically, led an expedition, I think it was in 92, and they decided to go to this ice shelf in Antarctica, in the Filchner–Ronne Ice Shelf to collect these ice cores.   And then the surprise was when they were progressing in the drilling, they realized that on the top part of the ice core was fresh water, meteoric snow that was compacted forming the ice. But they realized that below that part, there was a sea water that was frozen. And then they thought that these samples were very interesting, because they somehow store material from the past, and they shipped these samples to Alfred Werner Institute in Bremerhaven in Germany.   And half of the samples were stored for 40 years until I decided to contact the Institute and to propose this research. And I basically contacted the director of the Institute, and also the group of Frank Wilhelm, to propose the idea. And basically, I said, ‘Hey, I think what you have in your research is a valuable material that that can provide interesting answers for climate change and microbiology.' And they say, ‘Well, that's interesting. And we never thought about that.' And then we started a collaboration to dig into these questions.  Shipping the Ice Cores We had a meeting after one of the first pandemic lockdowns, when they allow [me] to travel. I went to Bremerhaven to have a personal meeting with the team. And we decided to ship some samples to Spain.   They arrived frozen and very well packaged and preserved in an isolated container. But it was really surprising to see that that they were delivered in the same compartment with a dry ham. That was a that was a funny story!  Sample Preparation When we received the samples, the first thing was to basically decontaminate the surface of the [ice]. Because when you unpackage, you have an ice core, pieces like a half meter. And then, we have to think that this ice core has been manipulated by different groups, different people. And you have to decontaminate the surface of the ice core in order to just have the center of the ice core for the for the investigation.  And basically, we adapted a protocol in order to make sure that we didn't have cross contamination from the rest of the from the surface.  So, what we did was we melted the center of the core—well, in fact, different parts of the core with different ages, from 1000 years old to 200 years old—and we melted in a very dedicated laminar flow hood that we have in a clean room. And then, we extracted the DNA from that piece. And in our case, the amount of DNA was so little that we had to amplify with some molecular techniques in order to have [enough] copies of this genetic material to do sequencing.  Sample Analysis I will say that we are in the middle of the project. We had, like, 2 years ongoing for the project.  The most surprising was 2 things. One, in the sea water, beneath the Antarctic, we discovered a very autoctonos (indigenous) viral community that was quite different from the rest of the world, I will say, from the rest of the ocean. So, I think this viral community is quite adapted to infect the microbes that are living in this peculiar environment beneath the Antarctica ice shelf.  And these viruses were carrying some genes that we think are very important for microbes. We call these genes auxiliary metabolic genes. And these genes are very important because somehow the viruses provide these pieces of information, of DNA material, to microbes that are driving important ecological roles, like, for example, carbon fixation.  It's very important, because carbon fixation is probably the primary step in all ecosystems—to provide food for the rest of the organisms. And if this is altering, or we are altering it with different factors—like temperature increase, like melting of the ice—its going to change these patterns and the rate of carbon fixation. This is going to produce a deep impact for the rest of organisms.  We are still investigating, but we think that it's interesting to think that microbes that live in our ocean now are responding to stressing factors like increasing temperature and also acidification by different ways. In fact, it is unclear—it is a very hot topic and a very hot question—because we don't know for sure what the fate of these microbes in our oceans is going to be. For example, people think that we are going to lose biodiversity. There are some hypotheses that say that heterotrophy is going to be more predominant in the sea water. But it's unclear, because we don't really have fossil records that can compare the past to the present, and this is what we can provide, or at least potentially provide. We can say, ‘Hey, we can go before the industrial revolution, before the CO2 increase, and try to compare series of different samples until the present in order to see if, for example, heterotrophy, or microbes that are heterotrophs, are more predominant in modern samples compared to unseen samples.   

Episode Summary Mother-Son duo, Brenda Wilson, Ph.D., professor of microbiology and the Associate Director of Undergraduate Education in the School of Molecular and Cellular Biology at the University of Illinois at Urbana Champaign and Brian Ho, Ph.D., researcher and lecturer at the Institute of structural and molecular biology, a joint institute between the Department of structural and molecular biology at the University College of London and the Department of Biological Sciences at Birkbeck University of London discuss the inspiration and motivation for their recent book, Revenge of the Microbes: How Bacterial Resistance is Undermining the Antibiotic Miracle, 2nd Edition, emphasizing the global nature of AMR and providing a unique perspective on what is needed to solve it. Ashley's Biggest Takeaways: Dynamics surrounding the AMR crisis are complex and require an understanding of many different perspectives, including those of the farmers, health care professionals, pharmaceutical companies and individuals, in order to foster true and lasting global collaboration on the issue. Point-of-care diagnostics are critical to improving treatment decisions and reducing hospital costs. Better communication and education are needed in order to rebuild trust in scientists and institutions. Continuous research is necessary, as AMR will continue to evolve. Citizens are a key piece of the puzzle when it comes to pushing for change and supporting solutions to AMR. Featured Quotes: Wilson: “I'll start with actually my Ph.D., which is talking about bacterial antibiotic biosynthesis. And so, I did some work in that arena, but since then, I've actually been working on bacterial protein toxins. These are very potent eukaryotic modulators that when bacteria get into the host, they release these proteins that are very large, that are able to interact with very specific cells. They actually get inside the cells—into the cytosol—and then they affect various signaling pathways in the host that can go anywhere from killing the cell to modulating some of the processes that the cell undertakes, even differentiating them and causing cancer. So, one of my main focuses in my lab has always been to understand the structure and function of these toxins, to understand how they affect the eukaryotic cell system. And then now that we know a lot about them, we're actually moving more into the direction of trying to basically use them as biologics. We have some platforms that we call bacterial toxin inspired drug delivery, where we're using the mechanisms of how they work and their exquisite specificities to be able to actually use them for therapeutic applications.” Ho: “I got my start doing molecular genetics, actually, with John Mekalanos at Harvard, and I was kind of at the ground floor of the seminal work looking at the Type VI secretion system. And so, I got a front row seat to the kind of discovery and a lot of the initial understanding of the system. And I've kind of taken that work and expanded beyond it to look at kind of the ways different bacteria interact with each other within microbial communities. So my current work is looking at both DNA conjugation as well as the type six antagonism, and how the bacterial interactions kind of work together to build a larger population dynamics and interface with like the hosts that kind of house a your microbial communities.” Antimicrobial Resistance Wilson: “In 2005 [when the first edition of Revenge of the Microbes was written], there was very little activity or understanding about antibiotic resistance and how important it was. Outside of the field, doctors were encountering it. But oftentimes what was happening is they just said, ‘Oh, well, we'll just find another drug, you know.' And pharmaceutical companies, they were recognizing that there was a problem, and they would go off trying to hunt for new ones. And then right around the late 90s, there was a big impetus, because they thought, ‘Oh, we, we have a miracle here, because we now do complete genomes. We can get out the comparative genomics and all the high throughput things, all the animations,' and that this would lead to many more new discoveries. And I think the pharmaceutical companies were very disappointed, and they started backing out of what they deemed a huge commitment. Two decades later, people already were starting to get aware, at least in the field, and even the industry and the physicians. People were getting aware, but I think that they were stumbling, because of their silos, in trying to get interactions with each other. And I think part of it was that they felt that, ‘Oh, we can try to solve it ourselves.' And in reality, this is a problem that that is concerning everyone, and everyone is contributing to it. Everyone has to find a solution to help, and we need to have more synergy. There have to be more interactions, and we have to do this at a much more global scale. And so that was sort of what, what we thought when we first started the [2nd edition of the book, Revenge of the Microbes].” Ho: “At that point, I was just starting my new faculty position, and so I started having to teach students directly. And a lot of students were coming in and giving their presentation on their research proposal or project that they have, and they very adamantly declared the reason why we have antibiotic resistance. ‘The problem is because doctors are over prescribing antibiotics.' And I'm scratching my head—a little like, ‘Hmm, that's a really confident statement that you're making.' Next student comes in and they're talking about, ‘Oh, it's all the farmers that are overusing antibiotics and causing the problem.' And then the next student comes in like, “Oh, the greedy corporations or pharmaceutical industry is trying to milk us for everything, and antibiotics are not profitable enough.' And, and I'm sitting here listening to the students who have a very narrow perspective. And clearly, they're getting it from whoever is teaching their classes. And so, it feels like every single perspective at every single stage, they only see things through their own eyes, and can't understand what the broader perspective is and why you have all these various different problems, and I guess we call them stakeholders in the thing. It is that that every different angle has its own personal motivations. Corporations do need to have money and persist to exist. Doctors, if you encounter a patient that is dying, well, you have a moral compulsion to actually treat them. And farmers having their livestock, well, their livelihood is at stake if they don't have their animals survive, right? And so, what I think was really important that we wanted to do is present the problem of antibiotic resistance and the way it works and why it's an issue, but also convey different perspectives on it, so that if people can kind of understand where everybody else is coming from, we can come together and have a more unified perspective, or understanding, at least, so that you're not thinking that everybody is this malicious actor, and you can actually work together to come with up with a complete solution.” Wilson: “The first book, was very important, because you needed to get people's attention right, right? But we got the attention. So, now let's come up with a plan! And we don't have a good plan. People are making progress. People are moving in the directions that need to be moved, coming up with alternatives, coming up with, you know, even financial solutions, to some extent. They're not enough, still, and it's going to take a global community to come forward and buy in to the problem. And I think we still have a large sector of our whole global community that are not really fully aware of what really this problem entails. They hear on the media and the news, ‘Oh, the crisis is here. We're in danger.' And then a year later, they say, ‘Well, what happened? Nothing's happened.' It hasn't impacted their lives yet, right? Or at least not in a way that they've noticed. And I think this is why we need more awareness. We need to get the word out there. We need to actually start having folks that make some of the big decisions, both financially, regulatory and other types of things, like education.” Ho: “One really big problem I think that COVID introduced us to, is that it's not just that we have to convince everybody it's important, but we have to also get people, in general, the population, to trust us. You know, that there is a problem. There's been a kind of an erosion in the trustworthiness, or trust in the institutions that we relied upon that are responsible for keeping everybody safe and healthy. And I think a big part of that is also communication education, that the populace needs to be better educated, but the communication level of people in charge, as well as researchers like us—we need to speak to the people in a way that people can understand.” Wilson: “We're not saying that we have a solution, but we do have some directions that, in many areas, have started, and we feel that they need more support. And we're hoping that folks that are reading the book actually appreciate that aspect of it, and then start realizing that, ‘Hey, I'm part of this solution too.' It can be very little—being mindful of making sure that we have clean water, making sure that we have food security, making sure that we stay healthy and, therefore, we don't have as many infections, right? Just little things like that that we can actually do as individuals, that as a whole population, will actually contribute to improving the situation. Then, of course, we have to support our leaders in making some of the decisions. We have to let them know that we care about this. And I think at this stage, what we're hoping is that we can maybe encourage some folks to take a citizen stand on this, to ask questions, to start going and probing and saying, ‘Hey, congress person, what are you doing about this?' And maybe just start the dialog. This is all we're doing, is starting a dialog.” Links for the Episode: The 2nd Edition of Revenge of the Microbes, details the intricacies of the antibiotic-microbe arms race. Beginning with a historical perspective on antibiotics and their profound impact on both modern medicine and present-day society. It also examines the practices and policies driving the discovery and development of new antibiotics, what happens to antibiotics once they are released into the environment, how antibiotic-resistant bacteria evolve and spread and the urgency for finding alternative approaches to combating infections. For anyone interested in antimicrobial resistance (AMR), this is a completely approachable 360-degree view of a very complex topic. Get your copy of Revenge of the Microbes today! Want to get involved and spread the word about AMR? Become an ASM Advocate Bacterial Pathogenesis: a Molecular Approach Take the MTM listener survey!

Joseph James, biologist at the U.S. Environmental Protection Agency, discusses his career trajectory and the creation of Binning Singletons, a unique mentorship program built on peer-to-peer networking at scientific meetings and conferences and was first implemented in 2019 at ASM Microbe. Links for the Episode Binning Singletons and Peer-to-Peer Networking Learn more about Binning Singletons. Contact Joe James: Joe@binningsingleton.com Follow Binning Singletons on Bluesky. Binning Singletons: Mentoring through Networking at ASM Microbe 2019—mSphere article. Binning Singletons: Tackling Conference Networking When You Don't Know Anyone—Guest post on Addgene Blog. Mastering a Mentoring Relationship as the Mentee—asm.org article that James says has really helped him explain Binning Singletons as a coaching form of mentorship. Mapping a Mentoring Roadmap and Developing a Supportive Network for Strategic Career Advancement—article on developing networks of mentors, another area Binning Singletons tries to address. #FEMSmicroBlog: Networking at Online Conferences (for Early Career Scientists). Take the MTM listener survey! James' Research Dietary lead modulates the mouse intestinal microbiome: Subacute exposure to lead acetate and lead contaminated soil. In situ differences in nitrogen cycling related to presence of submerged aquatic vegetation in a Gulf of Mexico estuary. Quantifying stream periphyton assemblage responses to nutrient amendments with a molecular approach. Analysis of Bacterial Communities in Seagrass Bed Sediments by Double-Gradient Denaturing Gradient Gel Electrophoresis of PCR-Amplified 16S rRNA Genes. Use of composite data sets for source-tracking enterococci in the water column and shoreline interstitial waters on Pensacola Beach, Florida.

Saeed Khan, Ph.D., Head of the Department of Molecular Pathology at Dow diagnostic research and reference laboratory and President of the Pakistan Biological Safety Association discusses the importance and challenges of biosafety/biosecurity practices on both a local and global scale. He highlights key steps for biorisk assessment and management and stresses the importance of training, timing and technology. Ashley's Biggest Takeaways Adequate biosafety and biosecurity protocols depend on a thorough understanding of modern challenges, and scientists must be willing and able to respond to new technological threats appropriately. In the microbiology lab, the threat goes beyond the physical pathogen. Implications of genomics and cyber security must be built into biorisk management techniques, including data storage and waste management practices. Risk assessments involve evaluation of both inherent and residual risk. Inherent risk is linked to the pathogen. Residual risk varies according to the lab, equipment, employee, environment, etc. As a result, biosafety and biosecurity risks are constantly changing, and assessments must be repeated strategically and often. Khan recommended repeating a risk assessment whenever a key variable in the equation changes, i.e., new equipment, new employee, new pathogen. He also recommended (at minimum) conducting routine risk assessments every 6 months, or twice a year. Featured Quotes:  “We need to have basic biosafety and biosecurity to stay away from these bugs and the modern challenges, like cyber biosecurity and genomics. These are the new areas, which are potential threats for the future, and where we need to train our researchers and students.” “Starting from simple hand washing or hand hygiene, the basic things we use are gloves, goggles and PPE to protect the workers, the staff and the patient from getting infected from the environment, laboratory or hospitals. These are the basic things, and it's very crucial, because if one is not using gloves in the lab or not wearing the lab coat, he or she may get infected from the sample, and the patient can get infected from the physician and doctors or nurse if they are not following the basic biosafety rules. These [things] are routinely important. Every day we should practice this.” “But there are [also] new challenges. Particularly in the microbiology lab, we [used to] think that once we killed the bacteria, then it's fine. But nowadays, it's not the way we should think about it. Though you kill the bacteria practically, it still has a sequence, [which] we call the genome, and if you have that information with you, you theoretically have the potential to recreate that pathogen… that can be used or maybe misused as well.” “[Working with] scripts of pathogens, like smallpox or the polioviruses, we call this synthetic biology. Different scientists are doing it for the right purposes, like for production of vaccines, to find new therapeutics, to understand the pathology of the diseases. But on [the other hand]—we call it dual use research of concern (DURC)—the same can be misused as well. That's why it's very important to be aware of the bugs that we are working with, and the potential of that pathogen or microbe, to the extent that can be useful or otherwise.” “So, we should be aware of the new concern of the technology, synthetic biology and DURC. These are new concepts—cyber, biosecurity and information security [are all] very much important these days. You cannot be relaxed being in the microbiology lab. Once we have identified a pathogen, declared a result to the patient and the physician, and it's been treated, we [still] need to be worried about waste management—that we discard that waste properly and we have proper inventory control of our culture. It should be safe in the locker or on in the freezers and properly locked, so we should not be losing any single tube of the culture, otherwise it may be misused.” Risk Assessment “The best word that you have used is risk assessment. So, it should gage the severity of the issue. We should not over exaggerate the risk, and we should not undermine the risk. Once the risk assessment been made, we can proceed.” “Right from the beginning of touching a patient or a sample of the patient until the end of discarding the sample, that is called biorisk management. It's a complete science that we need to be aware of—not in bits and pieces. Rather a comprehensive approach should be adopted, and each and every person in the organization should be involved. Otherwise, we may think [we are] doing something good, but someone else may spoil the whole thing, and it will be counterproductive at the end.” “We should involve each and every person working with us and the lab, and we should empower them. They should feel ownership that they are working with us, and they are [as] responsible as we are. So, this the whole process needs to be properly engaged. People must be engaged, and they should be empowered, and they should be responsible.” “Each and every lab has different weaknesses and strengths of their own, which play an important role in the risk assessment.” “There is inherent risk, which is linked with the pathogen, and there is another thing we call residual risk. So, residual risk everywhere and varies. Though the inherent risk may be the same, the residual risk is based on the training of the person, the lab facility that is available, the resources that labs have and the potential threats from the environment.” “It's not usually possible that you do a risk assessment every day. So, when you have different factors involving a new pathogen in your lab, you have new equipment in your in your lab, or some new employee in your lab—[a new] variable factor that is involved—you should [perform] the risk assessment. Otherwise, [a routine risk assessment] should [be done] twice a year, after 6 months.” “Training is important, and response time is very much crucial. And different technology plays a vital role, but the lack of technology should not be an excuse for not responding. There is always an alternative on the ground that you may do the risk assessment. And within the given resources and facility, we should mimic the technology and respond to any outbreaks or disease within our given resources.” Links for the Episode ASM Guidelines for Biosafety in Teaching Laboratories Pakistan Biological Safety Association Training to be a Biosafety Professional (video) Take the MTM listener survey!

Nicole Dubilier, Ph.D., Director and head of the Symbiosis Department at the Max Planck Institute for Marine Microbiology, has led numerous reserach cruises and expeditions around the world studying the symbiotic relationships of bacteria and marine invertebrates. She discusses how the use of various methods, including deep-sea in situ tools, molecular, 'omic' and imaging analyses, have illuminated remarkable geographic, species and habitat diversity amongst symbionts and emphasizes the importance of discovery-driven research over hypothesis-driven methods. Watch this episode: https://www.youtube.com/watch?v=OC9vqE1visc Ashley's Biggest Takeaways: In 1878, German surgeon, botanist and microbiologist, Heinrich Anton de Bary, first described symbiosis as the living together of two or more different organisms in close physical intimacy for a longer period of time.  These relationships can be beneficial, detrimental or commensal, depending on the organisms involved.  Microbial symbiosis research holds great potential to contribute to sustainable energy production and environmental health. Links for This Episode: Learn more about one of Dubilier's research vessels and see videos from the expidition. Functional diversity enables multiple symbiont strains to coexist in deep-sea mussels. Chemosynthetic symbioses: Primer. Take the MTM listener survey!

From Bovine Spongiform Encephalopathy (BSE) to Creutzfeldt-Jakob disease (CJD), Neil Mabbott, Ph.D., has worked for nearly 2 decades on understanding the mechanisms by which prion proteins become infectious and cause neurological disease in humans and animals. He discusses the remarkable properties of prions and addresses complexities surrounding symptoms, transmission and diagnosis of prion disease.

Episode Summary Timothy Donohue, Ph.D.—ASM Past President, University of Wisconsin Foundation Fetzer Professor of Bacteriologyand Director of the Great Lakes Bioenergy Research Center (GLBRC) calls genomics a game-changer when it comes the potential of microbes to create renewable resources and products that can sustain the environment, economy and supply chain around the world. He also shares some exciting new advances in the field and discusses ways his research team is using microorganisms as nanofactories to degrade lignocellulose and make a smorgasbord of products with high economic value. Take the MTM listener survey! Ashley's Biggest Takeaways: The bioeconomy can be broadly defined as the use of renewable resources, including microorganisms, to produce valuable goods, products and services. Microbes have the potential to create products that cannot be made by existing synthetic chemistry routes. Using raw, renewable resources to create a circular bioeconomy is beneficial to the environmental footprint, economic footprint and supply chain security around the globe. Links for This Episode: The theme of our Spring 2024 Issue of Microcosm, our flagship member magazine is Microbes and the Bioeconomy: Greasing the Gears of Sustainability, launches this week and features an article based on this MTM conversation. If you are an ASM Member, check back on Wed., June 30 for the newly published content! Not a member? Consider renewing or signing up today, and begin exploring endless potential to boulster your career and network with professionals, like Donohue, in your field.  Get Bioeconomy Policy Updates. Heading to ASM Microbe 2024? Check out this curated itinerary of sessions on the bioeconomy, including those discussing the use of algae for bioproduction and synthetic biology for natural product discovery. Learn more about the Great Lakes Bioenergy Research Center. MTM listener survey!

Rodney Rohde, Ph.D., Regents' Professor and Chair of the Medical Laboratory Science Program at Texas State University discusses the many variants, mammalian hosts and diverse neurological symptoms of rabies virus. Take the MTM listener survey! Ashley's Biggest Takeaways: Prior to his academic career, Rohde spent a decade as a public health microbiologist and molecular epidemiologist with the Texas Department of State Health Services Bureau of Laboratories and Zoonosis Control Division, and over 30 years researching rabies virus. While at the Department of Health Lab, Rohde worked on virus isolation using what he described as “old school” cell culture techniques, including immunoassays and hemagglutinin inhibition assays. He also identified different variants of rabies virus, using molecular biology techniques. Rohde spent time in the field shepherding oral vaccination programs that, according to passive surveillance methods have completely eliminated canine rabies in Texas. In the last 30-40 years, most rabies deaths in the U.S. have been caused by bats. Approximately 98% of the time rabies is transmitted through the saliva via a bite from a rabid animal. Post-exposure vaccination must take place before symptoms develop in order to be protective. Links for This Episode: Molecular epidemiology of rabies epizootics in Texas. Bat Rabies, Texas, 1996–2000. The Conversation: Rabies is an ancient, unpredictable and potentially fatal disease. Rohde and Charles Rupprecht, 2 rabies researchers, explain how to protect yourself. The One Health of Rabies: It's Not Just for Animals. MTM listener survey!

The scientific process has the power to deliver a better world and may be the most monumental human achievement. But when it is unethically performed or miscommunicated, it can cause confusion and division. Drs. Fang and Casadevall discuss what is good science, what is bad science and how to make it better. Get the book! Thinking about Science: Good Science, Bad Science, and How to Make It Better

Dr. James Morton discusses how the gut microbiome modulates brain development and function with specific emphasis on how the gut-brain axis points to functional architecture of autism. Watch James' talk from ASM Microbe 2023: Using AI to Glean Insights From Microbiome Data https://youtu.be/hUQls359Spo

Dr. Michael ginger, Dean of the School of Applied Sciences in the Department of Biological and geographical Science at the University of Huddersfield, in West Yorkshire, England discusses the atypical metabolism and evolutionary cell biology of parasitic and free-living protists, including Leishmania, Naegleria and  even euglinids.

Dr. Maria Eugenia Inda-Webb, Pew Postdoctoral Fellow working in the Synthetic Biology Center at MIT builds biosensors to diagnose and treat inflammatory disorders in the gut, like inflammatory bowel disease and celiac disease. She discusses how “wearables,” like diagnostic diapers and nursing pads could help monitor microbiome development to treat the diseases of tomorrow.   Subscribe (free) on Apple Podcasts, Spotify, Google Podcasts, Android, RSS or by email. Ashley's Biggest Takeaways Biosensors devices that engineer living organisms or biomolocules to detect and report the presence of certain biomarkers.   The device consists of a bioreceptor (bacteria) and a reporter (fluorescent protein or light). Inda-Webb's lab recently published a paper in Nature about using biosensors (Sub-1.4 cm3 capsule) to detect inflammatory biomarkers in the gut. The work is focused on diagnosing and treating inflammatory bowel disease, but Inda-Webb acknowledged that that is a large research umbrella. The next step for this research is to monitor the use of the biosensor in humans to determine what chemical concentrations are biologically relevant and to show that it is safe for humans to ingest the device. It is believed that the gut microbiome in humans develops in the first 1000 days to 3 years of life. Early dysbiosis in the gut has been linked to disease in adulthood. However, we do not have a good way to monitor (and/or influence) microbiome development. Inda-Webb hopes to use biosensors in diapers (wearables) to monitor microbiome development and prevent common diseases in adulthood. In 2015, Inda-Webb became ASM's first Agar Art Contest winner for her piece, “Harvest System.” Inda-Webb is the 2023 winner of the ASM Award for Early Career Environmental Research, which recognizes an early career investigator with distinguished research achievements that have improved our understanding of microbes in the environment, including aquatic, terrestrial and atmospheric settings. Learn More About ASM's Awards Program Featured Quotes: We engineer bacteria to sense particular molecules of interest—what we call biomarkers—if they are associated with a disease. And then, we engineer a way that the bacteria will produce some kind of molecule that we can measure—what we call reporter—so that could be a fluorescent protein or light, like the one that we have in this device. The issue is that inflammation in the gut is really very difficult to track. There are no real current technologies to do that. That is like a black box. And so, most of what we measure is what comes out from the gut, and has its limitations. It doesn't really represent the chemical environment that you have inside, especially in areas where you're inflamed. So, we really needed technologies to be able to open a window in these areas. The final device that I am actually bringing here is a little pill that the patient would swallow and get into the gut. And then they engineer bacteria that the biosensors, will detect, let's say, nitrous oxide, which is a very transient molecule. And the bacteria are engineered to respond to that in some way—to communicate with the electronics that will wirelessly transmit to your cell phone. And from there, to the gastroenterologist. We make the bacteria produce light. If they sense nitrous oxide, they produce light, the electronics read that, and the [information] finally gets into your phone. Part of the challenge was that we needed to make the electronics very very tiny to be able to fit inside the capsule. And also, the amount of bacteria that we use also is only one microliter. And so, imagine one microliter of bacteria producing a tiny amount of light. Finally, the electronics need to be able to read it. So that has been also part of the challenge. In this case, you have 4 different channels. One is a reference, and then the other 3 are the molecule of your choice. So, for example, what we show in the paper here is that we can even follow a metabolic pathway. So, you can see one more molecule turn into the other one, then into the other one. I'm really excited about that. Because normally we kind of guess as things are happening, you know, but here you can see in real time how the different molecules are changing over time. I think that's pretty exciting for microbiologist. The immediate application would be for a follow up. Let's say the patient is going to have a flare, and so you could predict it more much earlier. Or there's a particular treatment, and you want to see what is happening [inside the gut]. But for me, as a microbiologist, one of the things I'm most excited about will be more in the longer term. One of my favorite experiments that I do with the students is the Winogradsky column, and everyone gets super excited. So, we all have nice feelings for that. And it's basically a column where we asked the students to bring mud from a lake, for example, and then some sources of nutrients. And then, after 6months, you will see all the layers, which is super pretty—beautiful, nice colors. But actually, that gives the concept of how the microenvironment helps to define where, or how, bacteria build communities. And so, what I think this device is going to do is to help us identify what is this microenvironment and to characterize that. And then, from there, to know if [an individual's] microbiome is leaning towards the disease state, or if it's already in a serious or dangerous situation, to think about treatments that can lead to a more healthy state. So, I would just say it's really to have a window into the gut, and to be able to give personalized treatment for the patient. So, one application: I was thinking, I'm from the Boston area. So, one problem we have is getting a tick bite, right? After that, you could actually have to go through a very traumatic, antibiotic regime. I would imagine, in that case, you could [use the biosensor to] get the baseline [measurement], and then if you need to take these antibiotics, the doctors can follow how your microbiome is responding to that. Because one of the problems is that antibiotics changed the oxidation level [in the gut], and that really affects a lot the microbiome. To that point, for example, I get to know patients that they were athletes, and then, after antibiotic treatment, they have serious problems with obesity. Their life gets really messed up in many ways. And so, what I'm thinking is, if we could monitor earlier, there are a lot of ways that we could prevent that. We could give antioxidants; we could change the antibiotic. There are things that I think the doctor could be able to do and still do the treatment that we know. And of course, [although] we talk a lot about how much trouble antibiotics are, for certain things, we still need [them]. [The multi-diagnostic diaper] is one of my pet projects. I really love it. So yeah, basically, the issue is that the microbiome develops in the first 3 years. People even say like, 1000 days, you know. But there's really no way to monitor that. And now we're seeing that actually, if the microbiome gets affected, there are a lot of diseases that you will see in adult life. So, if we will be able to monitor the microbiome development, I really believe that we'll be able to prevent many of the diseases of tomorrow. What happens is that babies wear diapers. So, I thought it was really a very good overlap. We call that “wearables,” you know, like devices that you can wear, and then from there, measure something connected with health. So, in the diaper, I was excited because—different from the challenge with the ingested device, which was so tiny—here, we don't have the limitation of space. So, we could measure maybe 1000 different biomarkers and see how that builds over time. We can measure so many things. One could be just toxic elements that could be in the environment. I try to do very grounded science, and so, my question is always, ‘what's the actionable thing to do?' So, I'm thinking if there was a lot of toxicity, for example, in the carpet, or in the environment where you live, those are the easiest things to change, right? Then also, other things connecting more with the metabolism. [Often] the parents don't know that the kid has metabolic issues. So, before that starts to build and bring disease, it would be best if you could detect it as early as possible. From there, with symbiotics, we are thinking there are a lot of therapies that could engineer bacteria to produce the enzymes that the kid can't produce. We could also [develop] other products, like for example, a t-shirt to measure the sweat. I'm also thinking more of the milk. I'm very excited about how the milk helps to build the microbiome in the right way. And that that's a huge, very exciting area for microbiologists. And so, we could also have nursing pads that also measure [whether] the mother has the right nutrients. My family, my grandparents were farmers, and in Argentina, really the time for harvest is very important. You can see how the city and really the whole country gets very active. And at that time [during a course Inda-Webb was taking at Cold Spring Harbor] in this course, I could see that with yeast we were having a lot of tools that would allow us to be much more productive in the field. And I thought, ‘Oh, this feels like a harvest system for yeast.' Yes. So that was how it [Inda-Webb's winning agar artwork, ‘Harvest System'] came out. I really love the people. Here, [at ASM Microbe 2023], I really found that how people are bringing so much energy and really wanted to engage and understand and just connect to this idea of human flourishing, right, giving value to something, and saying, ‘okay, we can actually push the limits of what we know.' How beautiful is that? And you know, we can learn from that. That was very exciting. ASM Agar Art Contest Have you ever seen art created in a petri dish using living, growing microorganisms? That's agar art! ASM's annual Agar Art Contest is a chance for you to use science to show off your creative skills. Submissions Are Now Being Accepted! This year's contest theme is "Microbiology in Space." Head over to our Contest Details page to get all of the information about what you need to submit your entry. Submissions will be accepted until Oct. 28! Links for the Episode: Inda-Webb, et al. recent Nature publication: Sub-1.4 cm3 capsule for detecting labile inflammatory biomarkers in situ. Bacterial Biosensors: The Future of Analyte Detection. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Dr. Gary Procop, CEO of the American Board of pathology and professor of pathology at the Cleveland Clinic, Lerner School of Medicine discusses the importance of early detection and diagnosis in order to prevent fungal invasion leading to poor outcomes, particularly in immunocompromised patients. He emphasizes the importance of thinking fungus early, shares his passion for mentoring and talks about key updates in the recently released 7th Edition of Larone's Medically Important Fungi. Ashley's Biggest Takeaways Many invasive fungal infections are angiotrophic, meaning they actually grow toward, and into, blood vessels. Once the fungus has penetrated the blood vessel, the blood essentially clots, causing tissue downstream from the blood clot to die (infarction). When tissues that have been excised are viewed under the microscope, hyphal elements can be seen streaming toward or invading through the wall of the blood vessels. Once the clot forms, those hyphal elements can be seen in the center of the blood vessel where only blood should be. Antifungals cannot be delivered to areas where the blood supply has stopped. Therefore, treatment requires a combined surgical and medical approach, and the process is very invasive. Early detection can prevent these bad outcomes by allowing antifungal treatment to be administered before angioinvasion occurs. Links for the Episode: Expand your clinical mycology knowledge with the recently released 7th edition of Larone's Medically Important Fungi: A Guide to Identification. Written by a new team of authors, Lars F. Westblade, Eileen M. Burd, Shawn R. Lockhart and Gary W. Procop, this updated edition continues the legacy of excellence established by founding author, Davise H. Larone. Since its first edition, this seminal text has been treasured by clinicians and medical laboratory scientists worldwide. The 7th edition carries forward the longstanding tradition of providing high-quality content to educate and support the identification of more than 150 of the most encountered fungi in clinical mycology laboratories. Get your copy today with $1 flat rate shipping within the U.S. or order the e-book! ASM members enjoy 20% off at checkout using the member promo code. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

From antifungal resistance to disaster microbiology and tales of visible mold growing across the skin of patients following a tornado in Joplin, Missouri, Dr. Shawn Lockhart, Senior Clinical Laboratory Advisor in the Mycotic Diseases Branch at the CDC talks all things fungi—complete with references to pop TV shows and the recently released 7th Edition of Larone's Medically Important Fungi. Links mentioned: Larone's Medically Important Fungi: A Guide to Identification, 7th Edition (Use code: MCR20 at checkout for 20% off) CDC's Mycotic Diseases Branch conducts an annual training course on the identification of pathogenic molds.      

Dr. Kate Howell, Associate Professor of Food Chemistry at the University of Melbourne, Australia discusses how microbes impact the flavor and aroma of food and beverages and shares how microbial interactions can be used to enhance nutritional properties of food and beverage sources. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Dr. Steve Diggle, ASM Distinguished Lecturer and Microbiology Professor at the Georgia Institute of Technology in Atlanta, Georgia and Dr. Freya Harrison, Associate Microbiology Professor at the University of Warwick in Coventry, U.K., discuss the science behind medieval medical treatments and the benefits of interdisciplinary research. Ashley's Biggest Takeaways Diggle and Harrison met in Oxford, where Harrison was finishing up her Ph.D. and Diggle was doing background research for his work studying evolutionary questions about quorum sensing. When Diggle began searching for a postdoc, Harrison, who had been conducting an independent fellowship at Oxford and studying social evolution, applied. The AncientBiotics Consortium is a group of experts from the sciences, arts and humanities, who are digging through medieval medical books in hopes of finding ancient solutions to today's growing threat of antibiotic resistance. The group's first undertaking was recreation and investigation of the antimicrobial properties of an ancient eyesalve described in Bald's Leechbook, one of the earliest known medical textbooks, which contains recipes for medications, salves and treatments. The consortium found that the eyesalve was capable of killing MRSA, a discovery that generated a lot of media attention and sparked expanded research efforts.   The group brought data scientists and mathematicians into the consortium (work driven by Dr. Erin Connelly from the University of Warwick). Together, the researchers began scouring early modern and medieval texts and turning them into databases. The goal? To mathematically data mine these recipes see which ingredients were very often or non-randomly combined in ancient medical remedies. The group recently published work showing synergistic antimicrobial effects of acetic acid and honey. They are also working to pull out the active compounds from Bald's eyesalve and make a synthetic cocktail that could be added to a wound dressings. A 1,000-Year-Old Antimicrobial Remedy with Antistaphylococcal Activity. Medieval medicine: the return to maggots and leeches to treat ailments. A case study of the Ancientbiotics collaboration. Phase 1 safety trial of a natural product cocktail with antibacterial activity in human volunteers. Sweet and sour synergy: exploring the antibacterial and antibiofilm activity of acetic acid and vinegar combined with medical-grade honeys. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Dr. Jessica Lee, scientist for the Space Biosciences Research Branch at NASA's AIMS Research Center in Silicon Valley uses both wet-lab experimentation and computational modeling to understand what microbes really experience when they come to space with humans. She discusses space microbiology, food safety and microbial food production in space and the impacts of microgravity and extreme radiation when sending Saccharomyces cerevisiae to the moon. Ashley's Biggest Takeaways Lee applied for her job at NASA in 2020. Prior to her current position, she completed 2 postdocs and spent time researching how microbes respond to stress at a population level and understanding diversity in microbial populations. She has a background in microbial ecology, evolution and bioinformatics. Model organisms are favored for space research because they reduce risk, maximize the science return and organisms that are well understood are more easily funded. Unsurprisingly, most space research does not actually take place in space, because it is difficult to experiment in space. Which means space conditions must be replicated on Earth. This may be accomplished using creative experimental designs in the wet-lab, as well as using computational modeling. Links for the Episode: Out of This World: Microbes in Space. Register for ASM Microbe 2023. Add “The Math of Microbes: Computational and Mathematical Modeling of Microbial Systems,” to your ASM Microbe agenda. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Dr. Maria Gloria Dominguez-Bello, Henry Rutgers Professor of Microbiome and Health and director of the Rutgers-based New Jersey Institute for Food, Nutrition and Health, and Dr. Martin Blaser, Professor of Medicine and Pathology and Laboratory Medicine and director of the Center for Advanced Biotechnology and Medicine at Rutgers (NJ) discuss the importance of preserving microbial diversity in the human microbiome. The pair, whose research was recently featured in a documentary The Invisible Extinction, are on a race to prevent the loss of ancestral microbes and save the bacteria that contribute to human health and well-being.  Links for the Episode: The Invisible Extinction (documentary) Missing Microbes (book) Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues (article) (YouTube) Missing Microbes with Dr. Martin Blaser

Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for the 3rd , and final, episode in a unique 3-part segment, in which we share stories about the life and work of medial pioneers in infectious diseases. Here we discuss the career of Dr. Barry Marshall, the Australian physician who is best known for demonstrating in a rather unorthodox way that peptic ulcers are caused by the bacterium, Helicobacter pylori. Gaynes is author of Germ Theory: Medical Pioneers in Infectious Diseases, the 2nd edition of which will publish in Spring 2023. All 3 scientists highlighted in this special MTM segment are also featured in the upcoming edition of the book.

Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for the 2nd episode in a unique 3-part series, in which we share the impact of scientists at the heart of various paradigm shifts throughout scientific history. Here we discuss the life and career of Tony Fauci, the scientist who has been recognized as America's Top Infectious Diseases Doctor and “voice of science” during the COVID-19 pandemic. Ashley's Biggest Takeaways Fauci was born in Brooklyn, New York. He was a 2nd generation American whose parents came from Italy. Fauci's father was a pharmacist in Brooklyn and was very influential in his life. During high school, Fauci worked behind the counter at the family pharmacy and even delivered prescriptions by bicycle. He attended a Jesuit high school in Manhattan, and attended the College of Holy Cross. After college, Fauci attended Cornell Medical School in Manhattan, which was his first choice of medical school. Fauci graduated first in his class in medical school in the mid 1960's, right in the midst of the Vietnam War. During that time, after completing their initial residency training, virtually all doctors were drafted into one of the military services or the U.S. Public Health Service. Fauci accepted into the NIH program within the U.S. Public Health Service, where he acquired training and a fellowship in Clinical Immunology and Infectious Diseases. Fauci became the Director of the National Institute of Allergy and Infectious Disease (NIAID) in 1984. Fauci served as advisor to 7 U.S. presidents, including Ronald Regan, George H.W. Bush, Bill Clinton, George W. Bush, Barack Obama, Donald Trump and Joe Biden. 15 years after the creation of PEPFAR, Fauci reported, in the New England Journal of Medicine, that PEPFAR funded programs had provided antiretroviral therapy to 13.3 M people, averted 2.2 M perinatal HIV infections and provided care for more than 6.4 M orphans and vulnerable children. The first edition of "Germ Theory: Medical Pioneers in Infectious Diseases" is available now. The 2nd edition will publish in the spring of 2023.

Dr. Robert Gaynes, distinguished physician and professor of infectious diseases at Emory University, joins Meet the Microbiologist for a unique episode, in which we share the story of Françoise Barré-Sinoussi, the French, female scientist who discovered HIV and found herself at the heart of one of the most bitter scientific disputes in recent history. Subscribe (free) on Apple Podcasts, Spotify, Google Podcasts, Android, RSS or by email. Ashley's Biggest Takeaways The U.S. Centers for Disease Control and Prevention (CDC)'s Morbidity and Mortality Weekly Report first reported on a cluster of unusual infections in June of 1981, which would become known as AIDS. Evidence suggested that the disease was sexually transmitted and could be transferred via contaminated blood supply and products, as well as contaminated needles, and could be passed from mother to child. All hemophiliacs of this generation acquired AIDS (15,000 in the U.S. alone). The fact that the microbe was small enough to evade filters used to screen the clotting factor given to hemophiliacs indicated that the etiologic agent was a virus. AIDS patients had low counts of T-lymphocytes called CD4 cells. By 1993, the most likely virus candidates included, a relative of hepatitis B virus, some kind of herpes virus or a retrovirus. Howard Temin discovered reverse transcriptase, working with Rous sarcoma in the 50s and 60s. His work upset the Central Dogma of Genetics, and at first people not only did not believe him, but also ridiculed him for this claim. Research conducted by David Baltimore validated Temin's work, and Temin, Baltimore and Renato Dulbecco shared the Nobel Prize for the discovery in 1975. Robert Gallo of the U.S. National Institute of Health (NIH), discovered the first example of a human retrovirus—human T-cell lymphotropic virus (HTLV-1). Françoise Barré-Sinoussi worked on murine retroviruses in a laboratory unit run by Luc Montagnier, where she became very good at isolating retroviruses from culture. In 1982, doctors gave lab Montagnier's lab a sample taken from a with generalized adenopathy, a syndrome that was a precursor to AIDS. Barré-Sinoussi began to detect evidence of reverse transcriptase in cell culture 2 days after the samples were brought to her lab. Barré-Sinoussi and Luc Montagnier were recognized for the discovery of HIV with the 2008 Nobel Prize in Physiology or Medicine. Links for the Episode: From the ancient worlds of Hippocrates and Avicenna to the early 20th century hospitals of Paul Ehrlich and Lillian Wald to the modern-day laboratories of François Barré-Sinoussi and Barry Marshall, Germ Theory brings to life the inspiring stories of medical pioneers whose work helped change the very fabric of our understanding of how we think about and treat infectious diseases. Germ Theory: Medical Pioneers in Infectious Diseases The second edition of Germ Theory, which will include chapters on Françoise Barré-Sinoussi, Barry Marshall and Tony Fauci, will publish in Spring 2023.

Episode Summary Dr. Devin Drown, associate professor of biology and faculty director of the Institute of Arctic Biology Genomics Core at the University of Alaska Fairbanks, discusses how soil disturbance gradients in the permafrost layer impact microbial communities. He also explains the larger impacts of his research on local plant, animal and human populations, and shares his experience surveilling SARS-CoV-2 variants in Alaska, where he and colleagues have observed a repeat pattern of founder events in the state. Ashley's Biggest Takeaways Permafrost is loosely defined as soil that has been frozen for 2 or more years in a row. Some permafrost can be quite young, but a lot of it is much older—1000s of years old. This frozen soil possesses large storage capacity for walking carbon and other kinds of nutrients that can be metabolized by microbes as well as other organisms living above the frozen ground. About 85% of the landmass in Alaska is underlined by permafrost. Some is continuous permafrost, while other areas of landmass are discontinuous permafrost—locations where both unfrozen soil and frozen soil are present. As this frozen resource is thawing as a result of climate change, it is releasing carbon and changing soil hydrology and nutrient composition, in the active layer in the soil surrounding it. Changes in the nutrients and availability of those nutrients are also likely changing the structure of the microbial communities. Drown and team are using a combination of traditional (amplicon sequencing) and 3rd generation (nanopore) next sequencing (NGS) techniques to characterize the microbes and genes that are in thawing permafrost soil. Featured Quotes: “Globally, we've seen temperatures increase here in the Arctic. Changes in global temperatures are rising even faster, 2-3 times, and I've heard recent estimates that are even higher than that.” “These large changes in temperatures are causing direct impacts on the thaw of the permafrost. But they're also generating changes in other patterns, like increases in wildfires. We just had a substantial wildfire season here in Alaska, and those wildfires certainly contribute to additional permafrost thaw by sometimes removing that insulating layer of soil that might keep that ground frozen, as well as directly adding heat to the to the soil.” “There are other changes that might be causing permafrost thaw, like anthropogenic changes, changes in land use patterns. As we build and develop roads into areas that haven't been touched by humans in a long time. We're seeing changes in disruption to permafrost.” “Some people are quite interested in what might be coming out of the permafrost. We might see nutrients, as well as microorganisms that are moving from this frozen bank of soil into the active layer.” “We're using next generation sequencing techniques to characterize not only who is in these soils, but also what they're doing.” “I started as a faculty member in 2015. As I moved up to Alaska, I got some really great advice from a postdoctoral mentor that said, make sure you choose something local. I'm fortunate enough that I have access to permafrost thaw gradient, that's effectively in the backyard of my office.” “Just a few miles from campus, we have access to a site that's managed by the Army Corps of Engineers. They have a cold regions group up here that runs a more famous permafrost tunnel. So they've dug a deep tunnel into the side of a hill that stretches back about 40,000 years into permafrost. They also have a great field site that has an artificially induced permafrost thaw gradient, and a majority of our published work has been generated by taking soil cores from that field site.” “Maintaining that cold chain, whether it's experimental reagents or experimental samples, is a challenge for everyone. We're collecting active layer soil—the soil directly beneath our feet—so that's not at terribly extreme temperatures. But we do put it in coolers immediately upon extracting from the from the environment. Then we can bring it back to our lab where we can freeze it if we're going to use it for later analysis, or we can keep it at appropriately cool temperatures, if we're going to be working with the microbial community directly.” “We were most interested in looking for microbes that might have impacts on the above ground. ecosystem. So when we were characterizing the microbial community, we were doing that because we also wanted to link it to above ground changes.” “Changes in vegetation that might be driven by changes in microorganisms would certainly have an impact on the wildlife that are that are present at the site. So, just as an example, if we see a decrease in berries that might be present, that might decrease the interest from animals that rely on that [food source]. And so we might see changes in who's there.” “Outside of my research, we've seen changes in the types of plants present across northern latitudes. So different willows, for instance, are moving farther north, and that is leading animals, like moose, to move farther north. And so we might see changes in those kinds of patterns directly as a result of the microorganisms as well.” “We're really working to expand our efforts to move to other kinds of disturbances. I mentioned wildfires before, these are an important source of disturbance for boreal forest ecosystems. We have a project here in the interior, looking at the impacts of wildfires on microbial communities and how [these disturbances] might be changing the functional potential of microbial communities.” Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Dr. Marie Landry, Professor of Laboratory medicine and Infectious Diseases at Yale University School of Medicine and Dr. John Booss, former National Director of Neurology for the Department of Veteran's Affairs discuss the past, present and future of diagnostic virology. These proclaimed coauthors walk us through the impact of some of the most significant pathogens of our time in preparation for the launch of their 2nd edition of “To Catch a Virus,” a book that recounts the history of viral epidemics from the late 1800s to present in a gripping storytelling fashion. Ashley's Biggest Takeaways Coauthoring a book requires having great respect for the opinions of the person you are working with. The first human disease shown to be viral in nature was yellow fever, but for quite some time, the mode of disease transmission remained mysterious. In early 1881, Carlos Finlay of Cuba suggested that the disease could be spread by mosquitoes and significantly advanced the field. It wasn't until polio was discovered in the early 1900s that scientists determined that viruses could also be transmitted by and animals. The ability to grow virus in tissue culture was another huge advancement in the field of diagnostic virology, which eventually led to the development of the Salk inactivated polio vaccine (IPV). Although he did not seek the spotlight for his work, Walter Roe, was a bright, hardworking (and one of John's favorite) virologist, who made important advances in tissue culture, researched the role of retroviruses in animal cancer and discovered adenoviruses.   As a result of the COVID-19 pandemic, the clinical laboratory played a central role in public health. The importance of a laboratory diagnosis became more evident and next generation sequencing moved further into the clinical lab. Featured Quotes: “Advice that was given to me way back when I started on my first book is that you have to write about something you're passionate about. You have to really believe in the topic because otherwise it'll come across as superficial and artificial. So the very first step is do you really believe in, [and in the case of writing a book, that means] believe in what you're writing about.” – Booss. “Science is often projected as a steady stream of advances one after the other. But there is a certain amount, I think, of arbitrary choice at each step. And it's also true for for writing a book.” – Booss “In putting the book together, there are obviously major events that occurred in virology, major crises that move the field forward, an interplay, really, of the scientific advances, the clinical need of the crisis at hand and some very remarkable people. One highlight of this book is the way it does focus on individuals and their stories and how they contributed to that progress.” -Landry “When [pathogens] spread from a local area to a larger area geopolitical area or even globally, they become pandemic.” Polio “The most compelling virus that I can think of in my youth was obviously polio. So when I was a small child, polio was causing epidemics every summer, at the end of which, between 20 and 30,000 children in the United States were left either paralyzed or dead. So this was it really struck fear into parents hearts.” – Landry “And then came the oral polio vaccine. We lined up, and it was a very, very painless way to be immunized. So that was a tremendous success story, we've come very close to eliminating polio, because of a number of reasons it hasn't happened.” - Landry “There was a case recently of paralytic polio in New York, in an unvaccinated person. And I hope this is a wake-up call, we really thought we were about to eliminate before COVID. And then with those disruptions and others, there's been a little resurgence, but I hope that it will be accomplished soon.” -Landry COVID-19 “It's amazing how much the world did change. International economies collapsed. whole societies shut down. The education and socialization of children came to a screeching halt. As schools close, whole chasms of inequality opened up or were revealed. And also the poor and marginalized people were the ones who suffered most. And the U.S. cultural divisions interfered with attempts to block the disease. So that by 2022, the U.S. was unique in having over 1 million deaths. We lead unfortunately led the world in that regard.” – Booss “Sometimes we need a crisis to move us forward. And we saw this with the new vaccine platforms, especially the mRNA vaccine.” Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. Links From yellow fever and smallpox, to polio, AIDS and COVID-19, To Catch a Virus guides readers through the mysterious process of catching novel viruses and controlling deadly viral epidemics— and the detective work of those determined to identify the culprits and treat the infected. The new edition will be released October 15, 2022, available at asm.org/books

Dr. Wun-Ju Sheih, worked as a pathologist and infectious diseases expert with the CDC from 1995-2020. He recounts his experiences conducting high risk autopsies on the frontlines of outbreaks including Ebola, H1N1 influenza, monkeypox and SARS-CoV-1 and 2. He also addresses key questions about factors contributing to the (re)emergence and spread of pathogens and discusses whether outbreaks are becoming more frequent or simply more widely publicized. Ashley's Biggest Takeaways: • Pathologists are a group of medical doctors serving behind the line of the daily hospital activities. • Pathology service can be divided into atomic pathology and clinical pathology. The field covers all the laboratory diagnostic work in the hospital, and clinical microbiology or medical microbiology is actually a subdivision within the clinical pathology service. • Usually, a pathologist working in a hospital will examine and dissect tissue specimens from surgery or biopsy. • The pathologist also performs autopsies as requested to determine or confirm the cause of death. • Serving as first a clinician in Taiwan and then a pathologist in the United States has provided Sheih with the unique experience of evaluating patients from both the outside-in and the inside-out! • Even when a major outbreak of a known etiologic agent is taking place, confirmatory diagnosis is necessary for subsequent quarantine, control and prevention of the outbreak. • During major disease outbreaks, other pathogens do not go away, and we must simultaneously facilitate their timely diagnosis to ensure effective patient treatment and care. • SARS-CoV-2 appears to be transmitted more easily than SARS-CoV-1. One possible explanation for this is that the amount of viral load appears to be the highest in the upper respiratory tract of those with COVID-19, shortly after the symptoms develop. This indicates that people with COVID-19 may be transmitting the virus early in infection, just as their symptoms are developing…or even before they appear or without symptoms. • SARS-CoV-1 viral loads peak much later in the illness. • Asymptomatic transmission is rarely seen with SARS-CoV-1 infection. • Almost 99% of SARS-CoV-1 patients developed prominent fever when they started to carry infectivity. Temperature monitoring was therefore, very effective at detecting sick patients and facilitating prompt quarantining procedures, which effectively contained/minimized transmission of the virus. • This was not as effective for SARS-CoV-2, despite early attempts at temperature. monitoring. • SARS-CoV-2 was much harder to contain both because of the milder display of host symptoms and the demonstration of higher viral transmissibility.

Dr. Linden Hu, Vice Dean for Research at Tufts University in Boston Massachusetts and Paul and Elaine Chervinsky Professor in Immunology, discusses new and ongoing research pertaining to the prevention, treatment and diagnosis of human Lyme disease. He also discusses some of the key unanswered questions about Lyme, such as how B. burgdorferi adapts to different hosts and environments and why some patients have been known to exhibit persistent symptoms even after treatment.   Links mentioned: Webinar - Vector-Borne Disease in a Changing Climate https://asm.org/Webinars/Vector-Borne-Disease-in-a-Changing-Climate The Bulls-Eye Rash of Lyme Disease: https://asm.org/Articles/2018/April/going-skin-deep-investigating-the-cutaneous-host-p Pfizer and Valneva Initiate Phase 3 Study of Lyme Disease Vaccine Candidate VLA15 https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-valneva-initiate-phase-3-study-lyme-disease Could This Treatment Prevent Chronic Lyme Disease? https://news.northeastern.edu/2021/10/06/preventing-chronic-lyme-disease/ Promising New Drug Would Eradicate Lyme While Leaving Gut Microbes Alone: https://www.lymedisease.org/members/lyme-times/2022-spring-news/targeted-lyme-disease-drug/ A Tick's Meal: https://asm.org/Podcasts/TWiM/Episodes/A-Tick-s-Meal-TWiM-258 Evidence That the Variable Regions of the Central Domain of VlsE Are Antigenic during Infection with Lyme Disease Spirochetes https://journals.asm.org/doi/10.1128/IAI.70.8.4196-4203.2002 Distinct Roles for MyD88 and Toll-Like Receptors 2, 5, and 9 in Phagocytosis of Borrelia burgdorferi and Cytokine Induction https://journals.asm.org/doi/10.1128/IAI.01600-07

Dr. Mark O. Martin, Associate professor of biology at the University of Puget Sound in Tacoma, Washington is a distinguished educator with a well-known social media presence. He discusses how he became interested in microbiology and what drives his varied research foci, including #Microbialcentricity, bacterial predation, bioluminescence, tardigrades, microbial midwives and more. In the process, he delves into his passion for using art and other creative approaches to facilitate learning in the classroom, and shares some experience-driven wisdom about building confidence in STEM. Links for this Episode: Vertically transmitted microbiome protects eggs from fungal infection and egg failure https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-021-00104-5 The effects of Sceloporus virgatus cloacal microbiota on the growth of pathogenic fungi https://soundideas.pugetsound.edu/summer_research/426/ Sex-specific asymmetry within the cloacal microbiota of the striped plateau lizard, Sceloporus virgatus https://link.springer.com/article/10.1007/s13199-010-0078-y Predatory Prokaryotes: An Emerging Research Opportunity (pdf) https://www.pugetsound.edu/sites/default/files/file/martin2002_0.pdf Carleton College #LuxArt 2019 https://www.youtube.com/watch?v=fztiJ3o7uWs

Dr. Elizabeth Dinsdale, Matthew Flinders Fellow in Marine Biology in the College of Science and Engineering at Flinders University in Adelaide, Australia, uses genomic techniques to investigate the biodiversity of microbial communities in distinct ecological niches, including coral reefs, kelp forest and shark epidermis. She discusses how shotgun metagenomics is being used to characterize the architecture of microbial communities living in the thin layer of underlying mucus on shark's skin, and how understanding the function of these microbes is providing clues to important host-microbe interactions, including heavy metal tolerance. Ashley's Biggest Takeaways: Sharks belong to a subclass of cartilaginous fish called elasmobranchs and are unique in that their epidermises are covered in dermal denticles—overlapping tooth-like structures that reduce drag and turbulence, helping the shark to move quickly and quietly through the water. These dermal denticles are sharp (if you're going to pet a shark, make sure you go from the head to the tail to avoid getting cut!), and depending on the species of shark, may be more or less spread out across the epidermis. Where do microbes enter the story? Dermal denticles overlay a thin layer of mucus, which provides a distinctive environment for microbial life. Collecting microbial samples from underneath a shark's dermal denticles is quite difficult, and the technique varies by shark species (shark size, water depth and ability to bite all factor into the equation). Liz's team uses a specially designed tool that the group affectionately calls a “supersucker,” to create and capture a slurry of microbes and water for analysis. The team then uses shotgun metagenomics to identify and characterize the microbes in their collected samples. Sequencing has revealed biogeographical difference, as well as similarities in microbial architecture of whale sharks across the globe. There are 2 populations of whale sharks—one in the Atlantic Ocean and the other in the Indian Pacific Ocean. Samples collected from both populations have revealed that each individual whale shark, from within each aggregation, shares many of the same microbes. In fact, unlike algae which may share 1 to 2 microbial species, whale sharks share about 80% of microbes across every individual. Since many of the sharks don't cross aggregations, Liz's team is investigating the possibility of coevolution between microbes and hosts. Metagenomic sequencing also provides information about the function of the sequenced microbes. High presence of heavy metal-tolerant microbes has been found in the epidermis of all shark species that the team has analyzed. Sharks are known to carry high levels of heavy metals in their skin, muscle and even blood. However, muscle tissue samples contain lower concentrations than skin, indicating that there may be a density gradient in place, and raising questions about how microbes might be involved in this regulation. Is there a pathway by which the microbes metabolize and help to remove concentrations of heavy metals across the epidermis? Liz and her team are hoping to find out. Links: Elizabeth Dinsdale https://www.flinders.edu.au/people/elizabeth.dinsdale Tracking Pathogens via Next Generation Sequencing (NGS) https://asm.org/Magazine/2021/Spring/Tracking-Pathogens-via-Next-Generation-Sequencing Microbial Ecology of Four Coral Atolls in the Northern Line Islands https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001584 Coral Research https://coralandphage.org/research_coral.php  Metagenomic analysis of stressed coral holobionts https://pubmed.ncbi.nlm.nih.gov/19397678/  Metagenomic analysis of the microbial community associated with the coral Porites astreoides  https://pubmed.ncbi.nlm.nih.gov/17922755/

Dr. Mallory Choudoir, microbial ecologist and evolutionary biologist at the University of Massachusetts Amherst shares how she leverages microbial culture collections to infer ecological and evolutionary responses to warming soil temperatures. She discusses complexities of the soil microbiome and microbial dispersal dynamics, and introduces fundamental concepts about the intersection between microbes and social equity. Ashley's Biggest Takeaways: Microbial culture collections are fundamental resources, serving as libraries where diverse species of microbes are identified, characterized and preserved in pure, viable form. Culture collections ensure conservation of species diversity and sustainable use of the collected microbes. For soil microbiologists, like Mallory Choudoir, culture collections provide the opportunity to connect patterns of genomic variation and microbial physiology to the conditions under which a particular microbe was isolated. Soil is a complex environment from the perspective of a microbe. In order to coexist in such a biologically diverse environment, which consists of spatial heterogeneity, as well as heterogeneity in access to moisture and nutrients, microbes must evolve different strategies to survive as part of a stable community. Choudoir's field site is based in the Harvard Forest Long Term Ecological Research Program's field site, where coils are buried and have been heating the forest soil to 5 degrees above ambient temperatures for nearly 30 years. The study allows Choudoir and colleagues to observe and evaluate long-term responses to chronic soil warming stress. This research is important because microbes function as resources to the health and well-being of ourselves and our planet. Understanding how microbes adapt to biotic and abiotic stresses can help inform future conservation strategies, biotechnological approaches and applications and equitable allocation of microbial resources. Visit https://asm.org/mtm for links mentioned

Peter Hotez talks about the global impact and historical context of neglected tropical diseases. He also highlights important developments in mass drug administration and vaccine research and shares why he chose to publish the third edition of Forgotten People, Forgotten Diseases during the COVID-19 pandemic. Ashley's Biggest Takeaways Neglected Tropical Diseases (NTDs) are chronic and debilitating conditions that disproportionately impact people in low- and middle-income countries (LMICs).  Many of these diseases are parasitic, such as hookworm infection, schistosomiasis and chagas disease; however, in recent years, several non-parasitic infections caused by bacteria, fungi and viruses, as well as a few conditions that are not infections, including snake bite and scabies (an ectoparasitic infestation), have been added to the original NTD framework (established in the early 2000s).  What do most NTDs have in common? High prevalence. High mortality; low morbidity. Disabling. Interfere with people's ability to work productively.  Impact child development and/or the health of girls and women. Occur in a setting of poverty and actually cause poverty because of chronic and debilitating effects. Hotez and his colleagues recognized that there is a uniqueness to the NTDs ecosystem, and they began putting together a package of medicines that could be given on a yearly or twice per year basis, using a strategy called Mass Drug Administration (MDA). This involved the identification of medicines that were being used on an annual basis in vertical control programs and combining those medications in a package of interventions that costs about $0.50 per person per year. “Throw in an extra 50 cents per person and we could double or triple the impact of public health interventions,” he explained.   Emerging diseases, such as SARS-CoV-2, capture the attention of the public for obvious reasons. They pose an imminent threat to mankind. NTDs are not emerging infections, but they are ancient afflictions that have plagued humankind for centuries and, as a consequence, have had a huge impact on ancient and modern history. One of the reasons we have mainland China and Taiwan today may have been, in part, due to a parasitic infection, Schistosomiasis. Hotez and colleagues at the Texas Children's Center for Vaccine Development have developed a COVID-19 vaccine, based on simple technology, similar to what is used for the Hepatitis B vaccine. They hope to release the vaccine for emergency use in resource poor countries like India and Indonesia.  When asked about the timing of the publication of his book, the third edition of Forgotten People, Forgotten Diseases, Hotez acknowledged the difficulty of helping countries understand that NTDs have not gone away. COVID-19 is superimposed on top of them, and the pandemic has done a lot of damage in terms of NTD control. Although social disruption has interfered with the ability to deliver mass treatments, Hotez said that it has been gratifying to see that the USAID and their contractors have responded by putting out guidelines about how to deliver mass treatments with safe social distancing. “As a global society, we have to figure out how to walk and chew gum at the same time,” he said. “We've got to take care of COVID, but we really must not lose the momentum we've had for NTDs because the prevalence is starting to decline and we're really starting to make an impact.”

Rita Colwell has made major advances in basic and applied microbiology, largely focused on Vibrio cholerae. She describes several lines of evidence for the environmental niche of the bacterium, as well as her work to predict and prepare for cholera outbreaks. Colwell closes with her thoughts on why it's a great time to be a microbiologist.

Denise Akob discusses her studies of microbial communities of contaminated and pristine environments using life science and earth science techniques. She discusses how to figure out “who’s there,” how to optimize select natural microbial activities, and her career path into government research. Julie’s Biggest Takeaways: Biogeomicrobiology straddles the life science and earth science fields. This is a growing area of research in the academic setting as well as in the private sector, where one can contribute to hydrogeology or bioremediation efforts.   What happens on the surface when extracting resources like natural gases? Wastewater from hydraulic shale fracking, or fracking, can contaminate microbes. Preliminary data suggests that microbes that thrive in that wastewater can be a fingerprint for surface contamination, and this is one of the areas of active research in Akob’s lab. Additionally, microbes can respond to contaminants to remove that risk and remediate the spills. One trip to the field can provide samples for years of analysis. From one sample, scientists can conduct: Microbiome studies through amplicon sequencing to understand population structures. Metagenomics studies to understand functional potential. Biochemical studies to understand active metabolic processes. Akob asks how to make natural microbial degraders happy. For example: acetylene, a triple-bonded carbon compound, can inhibit degradation of chlorinated solvents, a potent groundwater contaminant. By studying the microbes that use acetylene as a primary energy source (acetylenotrophs), this removes this inhibition caused by acetylene and the chlorinated solvent-degraders can increase their activity.   Akob studies pristine environments to understand natural microbial communities. A cave she studied in Germany was ‘ultra pristine,’ discovered while building a highway. Understanding natural processes, such as the biomineralization promoted during stalagmite and stalactite formation helps scientists imagine how to use tehse processes in other applications. Links for this Episode: Mumford AC et al. Common Hydraulic Fracturing Fluid Additives Alter the Structure and Function of Anaerobic Microbial Communities. Applied and Environmetnal Microbiology. 2018. Akob DM et al. Acetylenotrophy: a Hidden but Ubiquitous Microbial Metabolism? FEMS Microbial Ecology. 2018. Akob DM et al. Detection of Diazotrophy in the Acetylene-Fermenting Anaerobic Pelobacter sp. Strain SFB93. Applied and Environmental Microbiology. 2017. ASM Article: The Microbial World of Caves James J, Gunn AL, and Akob DM. Binning Singletons: Mentoring through Networking at ASM Microbe 2019. mSphere. 2020. HOM Tidbit: Scientists Find Ancient Cave Dwelling Resistant Bacteria ASM Press: Women in Microbiology  

How does tick biology influence their ability to transmit disease? Marshall Bloom explains the role of the tick salivary glands in Powassan virus transmission and the experiments that led to this discovery. He also provides a historical background for the Rocky Mountain Labs in Hamilton, Montana, and talks about the 3 elements to consider when working with potentially harmful biological agents. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS or by email. Julie’s Biggest Takeaways There are 3 elements to consider when working with potentially harmful biological agents: Biosafety: protecting the laboratory workers from the infectious agents in the lab. Biocontainment: protecting the community by keeping the infectious agent contained within the facility. Bioassurity: protecting the individual by ensuring those working with infectious agents are capable to do so. You need 4 bites of an APPLE for full lab safety, for work in labs from high school level through biosafety level 4: A: Administration. Training, paperwork, etc. P: Personal protective equipment (PPE). Varies from gloves to positive pressure suits, depending on the microorganisms under study. PL: Laboratory procedures. Standard operating protocols. E: Engineering. Biosafety cabinets and labs that have protective features. Most of the vector-borne flaviviruses, including Powassan virus, don’t cause overt disease in the people they infect, so many people never know they’ve been infected. Without serological surveys, it’s difficult to know the full range of infected individuals versus those that develop serious disease. Serious disease often manifests in neurological symptoms such as encephalitis, with 10-15% mortality rate; half of those suffering neurological disease will continue to have serious sequelae for years. The Rocky Mountain Labs was once the world reference center for ticks: it held thousands of samples which represented the type species for the entire world. The tick salivary glands look like a bunch of grapes: the stem of the grapes is a series of branching ducts. The “grapes” at the end of the ducts are the acini, which is Latin for ‘little sac.’ These acini play a major role in tick feeding, and different types of acini play different functional roles: Type 1 acini: cells have no granules. Acini involved with fluid exchange. Type 2 and type 3 acini: cells with granules. Cells degranulate to release vasoactive compounds into tick saliva during feeding. Featured Quotes “The first isolation of Powassan virus was from a little boy in Powassan, Canada in 1958. If you look at the cases over the years, the numbers are going up, but compared to Lyme disease, they’re pretty low: there’s been less than 200 cases, all told.” “Amazingly, the Powassan virus can be transmitted in as little as 15 minutes….[and] a female tick can take days to get a full meal.” “I take a tick-centric view. If I can anthropomorphize, as my old friend Stanley Falkow used to say, he’d say ‘think like the microbe.’ The microbe doesn’t really care if we get sick or not. The microbe is just trying to make a living and survive.” “One of the really surprising things is that infected ticks can infect uninfected ticks, if they are feeding right next to each other. Ticks like to feed in groups: it’s called co-feeding. The virus can transferred really quickly, 15 min, which is way faster than the virus can go through a replication cycle. What that means to me is that the ticks are infecting each other….we want to investigate the role of co-feeding.” “If something sounds like fun or sounds important, and especially if something sounds fun AND important, then you should do it.” Links for this Episode: Paules CI et al. Tickborne Diseases--Confronting a Growing Threat. New England Journal of Medicine. August 2018. Amazon: Fighting Spotted Fever in the Rockies by Esther Gaskins Price  New York Times: Kay Hagan obituary Grabowski JM et al. Dissecting Flavivirus Biology in Salivary Gland Cultures from Fed and Unfed Ixodes scapularis (Black-Legged Tick). mBio. January 2019. ASM on Instagram Grabowski JM, Offerdahl DK, and Bloom ME. The Use of Ex Vivo Organ Cultures in Tick-Borne Virus Research. ACS Infectious Disease. Marhc 2018. Twitter thread from @BugQuestions: Rocky Mountain Spotted Fever and Howard Ricketts History of Microbiology Tidbit: A Short History of the Screwworm Program

What kinds of microorganisms can degrade oil? How do scientists prioritize ecosystems for bioremediation after an oil spill? Joel Kostka discusses his research and the lessons from the Deepwater Horizon oil spill that will help scientists be better prepared for oil spills of the future. Links for this Episode: Joel Kostka Lab Website Kostka J. et al. Hydrocarbon-Degrading Bacteria and the Bacterial Community Response in Gulf of Mexico Beach Sands Impacted by the Deepwater Horizon Oil Spill. Applied and Environmental Microbiology. 2011. Shin B. et al. Succession of Microbial Populations and Nitroget-Fixation Associated With the Biodegradation of Sediment-Oil-Agglomerates Buried in a Florida Sandy Beach. Scientific Reports. 2019. Bociu I. Decomposition of Sediment-Oil-Agglomerates in a Gulf of Mexico Sandy Beach. Scientific Reports. 2019. Overhold W.A. et al. Draft Genome Sequences for Oil-Degrading Bacterial Strains from Beach Sands Impacted by the Deepwater Horizon Oil Spill. Genome Announcements. 2013. Gulf of Mexico Research Initiative ASM Colloquia Report: Microbial Genomics of the Global Ocean System ASM Article: Microbiomes: An Origin Story Joyful Microbe Blog: How to make a Winogradsky column Small Things Considered: How to Build a Giant Winogradsky Column 20% off The Invisible ABCs for MTM listeners! Use promo code: ABC20 at checkout.

How do arboviruses evolve as they pass between different hosts? Greg Ebel discusses his research on West Nile virus evolution and what it means for viral diversity. He also talks about using mosquitos’ most recent blood meal to survey human health in a process called xenosurveillance. Julie’s Biggest Takeaways: Mosquitoes and other arthropods have limited means of immune defense against infection. One major defense mechanism is RNA interference (RNAi). RNAi uses pieces of the West Nile viral genome to select against the viral genome, which helps select for broadly diverse viral sequences. The more rare a viral genotype, the more likely it is to escape negative selection inside the mosquito host, allowing this viral sequence to increase in frequency.  West Nile virus passes largely between birds and mosquitos. Culex mosquitos tend to prefer birds, and this leads to an enzootic cycle for the virus passing between birds and mosquitos. The viral life cycle inside the mosquito has several important steps:  The virus first enters as part of the mosquito blood meal.  The virus infects epithelial cells of the mosquito midgut. After 3-5 days, the virus leaves the midgut (midgut escape) to enter the mosquito hemolymph. In the next mosquito blood meal, virus is expelled with saliva, which has anticoagulant activity. West Nile virus selection undergoes cycles of selection as it passes from vertebrates (mostly birds) to invertebrates (mosquitos): In vertebrates, the virus must escape to cause viremia in a short period of time for replication to occur before the immune system recognizes and eliminates the virus. This leads to purifying selection, or elimination of amino acid variation that decreases viral protein function. In mosquitos, the virus spends several days in the midgut epithelial cells and then hemolymph, leading to a longer selection time. This leads to more viral diversity in the mosquito host. RNAi further drives population diversity. Through stochasticity, a single viral population will often come to dominate a single infected mosquito. How do scientists know which virus replicates best? Competitive fitness tests measure which virus grows to a higher population in a given environment. A manipulated virus (one passaged in a mosquito or selectively mutated at distinct sequences) and its non-manipulated parent sequence are inoculated at known proportions, and given a certain amount of time to replicate. By measuring the final proportions, Greg and his team can determine which sequence was more fit in that given environment.  Xenosurveillance uses mosquitoes to detect a wide array of pathogens at clinically relevant levels. Testing began with in vitro blood-bag feeding, and was validated with studies in Liberia and Senegal. The microorganism sequences are so diverse that the information was used to identify novel human viruses. These studies also provide insight into mosquito feeding habits, which helps in disease modeling. Links for this Episode:  Greg Ebel Lab Website Rückert C. et al. Small RNA Responses of Culex Mosquitoes and Cell Lines during Acute and Persistent Virus Infection. Insect Biochemistry and Molecular Biology. 2019. Grubaugh N.D. et al. Mosquitoes Transmit Unique West Nile Virus Populations during Each Feeding Episode. Cell Reports. 2017. Grubaugh N.D. and Ebel G.D. Dynamics of West Nile Virus Evolution in Mosquito Vectors. Current Opinion in Virology. 2016. Fauver J.R. et al. Xenosurveillance Reflects Traditional Sampling Techniques for the Identification of Human Pathogens: A Comparative Study in West Africa. PLoS Neglected Tropical Diseases. 2018. Fauver J.R. The Use of Xenosurveillance to Detect Human Bacteria, Parasites, and Viruses in Mosquito Bloodmeals. American Journal of Tropical Medicine and Hygiene. 2017. Tracey McNamera: Canaries in the Coal Mine TEDxUCLA New York Times: Encephalitis Outbreak Teaches an Old Lesson. 1999. ASM Article: The One Health of Animals, Humans, and Our Planet: It’s All Microbially Connected    

How can the intricate relationship between soil microbiota and plants be managed for improved plant health? Linda Kinkel discusses new insights into the plant rhizosphere and the ways that some Streptomyces isolates can protect agricultural crops against bacterial, fungal, oomycete, and nematode infections. Julie’s Biggest Takeaways: The soil microbiome is extremely dynamic, with boom-and-bust cycles driven by nutrient fluxes, microbial interactions, plant-driven microbial interactions, and signaling interactions. Finding the source of these boom-and-bust cycles can help people to manage the microbiome communities and produce plant-beneficial communities for agricultural purposes.  Rhizosphere soil is soil closely associated with the root and is distinct from rhizoplane soil that directly touches the root. The endophytic rhizosphere are those microbes that get inside the root. Many scientists view these communities as a continuum rather than sharply delineated. Plants provide necessary carbon for the largely heterotrophic soil microbiota, and these microorganisms help the plants in several ways too:  Microbes mediate plant growth by production of plant growth hormones. Microbes provide nutrients through mechanisms like nitrogen fixation or phosphorus solubilization. Microbes protect the plant from stress or drought conditions. Through a University of Minnesota plant pathology program, potatos were passaged in a field for over 2 decades to study potato diseases. Over time, researchers found fewer diseases in test crops, which led the plot to be abandoned in the late 1970s. In the 1980s, Dr. Neil Anderson planted potatoes to see if they would develop disease, but neither Verticillium wilt nor potato scab developed among the plants. Soil from the field (and on the potatoes) contained Streptomyces isolates that showed antimicrobial activity against bacteria, fungi, nematodes, and oomycetes. This discovery led Neil, new University of Minnesota professor Linda, and their collaborators to study the antimicrobial activity of natural Streptomyces isolates from around the world. Inoculation quickly adds specific microbial lineages to soil microbiome communities. Alternatively, land can be managed by providing nutrients to encourage the growth of specific species, like Streptomyces, within a given plot, but this takes longer to develop. How are soil microbiomes inoculated? Microbes can be: Added to the seed coating before planting.  Placed in the furrow when the seed is planted. Distributed into the irrigation system. Links for this Episode: Linda Kinkel website at University of Minnesota Essarioui A. et al. Inhibitory and Nutrient Use Phenotypes Among Coexisting Fusarium and Streptomyces Populations Suggest Local Coevolutionary Interactions in Soil. Environmental Microbiology. 2020. Schlatter D.C. et al. Inhibitory Interaction Networks Among Coevolved Streptomyces Populations from Prairie Soils. PLoS One. 2019.  Schlatter D.C. et al. Resource Use of Soilborne Streptomyces Varies with Location, Phylogeny, and Nitrogen Amendment. Microbial Ecology. 2013. Small Things Considered blog: Are Oomycetes Fungi or What? International Year of Plant Health HOM Tidbit: Austin-Bourke P.M. Emergence of Potato Blight, 1843-1846. Nature. 1965.  

Pathogenic E. coli are different than lab-grown or commensal E. coli found in the gut microbiome. Alfredo Torres describes the difference between these, the method his lab is using the develop vaccines against pathogenic E. coli, and how this same method can be used to develop vaccines against Burkholderia infections. Julie’s Biggest Takeaways: coli plays many roles inside and outside the scientific laboratory: Laboratory E. coli strains used by scientists to study molecular biology. Commensal E. coli strains contribute to digestion and health as part of the intestinal microbiome. Pathogenic E. coli strains have acquired factors that allow them to cause disease in people The pathogenic E. coli associated with diarrheal disease are the ones named for their O-antigen and flagellar H-antigen, such as O157:H7. There are about 30 E. coli strains with various combinations of O-H factors known to cause diarrheal disease in people.  The E. coli Shiga toxin (though not the bacterium itself) can pass through the epithelial cell layer to become systemic, and eventually the toxin will accumulate in the kidneys. This can lead to patients experiencing hemolytic uremic syndrome (HUS) and kidney failure, leading to lifelong dialysis or need for a transplant. An immune response that prevents the E. coli from attaching will prevent the bacterium from secreting toxin in close proximity to the epithelial cells and decrease likelihood of HUS development. Burkholderia is a bacterial genus whose member species have been weaponized in the past, and which remain potent disease-causing agents around the world.  B. mallei causes glanders, a disease mostly of horses and their handlers. It is a respiratory infection that can become systemic if not treated. B. pseudomallei causes melioidosis, a disease that can manifest in many ways. It is endemic in many tropical regions around the world, found in over 79 countries so far. Coating gold nanoparticles with antigens against which the immune response will be protective is a method Alfredo has used for a number of candidate vaccines, including one against E. coli and one against B. pseudomallei. The nanoparticles can have the gold cleaved off to provide different functional variants of the same vaccine.  Links for this Episode: Alfredo Torres webpage at University of Texas Medical Branch McWilliams BD and Torres AG. Enterohemorrhagic Escherichia coli Adhesins. Microbiology Spectrum. 2013. Sanchez-Villamil JI et al. Development of a Gold Nanoparticle Vaccine against Enterohemorrhagic Escherichia coli O157:H7. mBio. 2019. Wiersinga WJ et al. Melioidosis. Nature Reviews Disease Primers. 2018.  Khakhum N. et al. Evaluation of Burkholderia mallei ΔtonB Δhcp1 (CLH001) as a live attenuated vaccine in murine models of glanders and melioidosis. PLOS Neglected Tropical Diseases. 2019. Torres AG. Common Sense Can Keep You Safe in E. coli Outbreak. Galveston County Daily News. 2020. ABRCMS: Annual Biomedical Research Conference for Minority Students MTM: Burkholderia pseudomallei & the neglected tropical disease melioidosis with Direk Limmathurotsakul HOM Tidbit: Kiyoshi Shiga Biography in Clinical Infectious Diseases  

Does the fetus have a microbiome? How does the placenta prevent infection? Carolyn Coyne talks about placental structure and biology, and why studying the maternal-fetal interface remains a critical area of research. Julie’s Biggest Takeaways: The placenta forms within 3-5 days post conception as a single layer of cells surrounding the fertilized embryo. These cells differentiate and develop into more complex structures. Very few microbes cause fetal disease. Of those that do, the disease-causing microorganisms are diverse and can lead to serious congenital defects or even death of a developing fetus. These microbes are largely grouped into the TORCH (now TORCH-Z) microorganisms: Toxoplasma gondii Other (a variety of different bacteria and viruses) Rubella Cytomegalovirus Herpesviruses Zika virus The fetus is immunologically immature and unable to protect itself. Some of the maternal immunological molecules (such as maternal antibodies) cross the placenta to protect the fetus, but that only happens during later stages of fetal development. Between the first and second trimesters, the maternal vasculature reorganizes and maternal antibodies can begin to reach the fetus. This increases over time, until the end of the third trimester, when there is a higher concentration of maternal antibodies in fetal blood than in maternal blood. In the later stages of development, the placenta is coated in a layer of fused cells, leading to a shared cytoplasm that covers the entire surface area of the placenta. This fused-cell layer is formed from syncytiotrophoblasts, and the fusion is facilitated by the activity of an endogenous retrovirus fusion protein. Syncytiotrophoblasts are extremely resistant to infection with a number of different pathogens, and pathogen types. In initial tests experiments, Carolyn and her research team discovered that these cells releasing certain antimicrobial molecules to share protective properties. Syncytiotrophoblasts secrete type III interferons, which play a big role at barrier surfaces such as the airway and the gut—but unlike these barriers, the syncytiotrophoblast cells secrete type III interferons constitutively. Links for this Episode: Carolyn Coyne Website on the University of Pittsburgh School of Medicine Arora N. et al. Microbial Vertical Transmission during Human Pregnancy. Cell Host & Microbe. May 2017.  Coyne C.B. The Tree(s) of Life: The Human Placenta and My Journey to Learn More About It. PLoS Pathogens. April 2016. Ander S.E. et al. Human Placental Syncytiotrophoblasts Restrict Toxoplasma gondii Attachment and Replication and Respond to Infection by Producing Immunomodulatory Chemokines. mBio. January 2018. Wells A.I. and Coyne C.B. Type III Interferons in Antiviral Defenses at Barrier Surfaces. Trends in Immunology. October 2018.  Ander S.E. Diamond M.S. and Coyne C.B. Immune Responses at the Materna-Fetal Interface. Science Immunology. January 2019. HOM Tidbit: Women in Microbiology HOM Tidbit: Small Things Considered blog post: Retroviruses, the Placenta, and the Genomic Junk Drawer  

Are there drugs that can treat coronaviruses? Timothy Sheahan talks about his drug discovery work on a compound that can inhibit all coronaviruses tested so far, and tells how his career path  took him to pharmaceutical antiviral research and then back to academia. Julie’s Biggest Takeaways: Even though the MERS-CoV was discovered as a human pathogen in 2012, it was likely percolating as a disease agent for a long time before that. Banked camel serum provides evidence that the virus had been circulating in camels for several decades prior. Differentiated ex vivo lung cultures allow study of virus infection in a 3D model representation for studying viral infection, including target cell types of both MERS-CoV and SARS-CoV. SARS-CoV prefers ciliated epithelial cells Ace2 MERS-CoV prefers nonciliated epithelial cells DPP4 Coronavirus disease in people takes place over a course of about 2 weeks. In mice, the disease is similar, but progression is faster, taking about 1 week.  The drug remdesivir (RDV) is a nucleoside analog that inhibits the coronavirus RNA-dependent RNA polymerase (RDRP). Remdesivir activity has not been tested against nCoV2019, but similarity to other viruses is promising. Bioinformatic approaches show that the nCoV2019 RDRP is 99% similar and 96% identical to SARS-CoV RDRP. Remdesivir works against every coronavirus tested so far, including viruses with highly divergent RDRP sequences, so remdesivir is likely to be effective again nCoV2019. Experiments must still be performed before reaching this conclusion, of course. Tim also hopes to discover the genetic determinants that will allow a chronic hepatitis C virus (HCV) infection in mice, but not standard inbred mice. He uses outbred mice meant to mimic the diversity of the human population, and strengthen the results. Understanding these determinants would inform human studies to better understand chronic HCV infection. Links for this Episode: MTM Listener Survey, only takes 3 minutes. Thanks! TWiV 584: Year of the Coronavirus Timothy Sheahan website at University of North Carolina Sheahan T.P. et al. Broad-Spectrum Antiviral GS-5734 Inhibits both Epidemic and Zoonotic Coronaviruses. Science Tranlational Medicine. 2017. Sheahan T.P. et al. Comparative Therapeutic Efficacy of Remdesivir and Combination Lopinavir, Ritonavir, and Interferon Beta against MERS-CoV. Nature Communications. 2020. Agostini M.L. et al. Coronavirus Susceptibility to the Antiviral Remdesivir (GS-5734) is Mediated by the Viral Polymerase and the Proofreading Exoribonuclease. mBio. 2018. ASM Coronavirus Resource Page HOM Tidbit: Baltimore D. In Vitro Synthesis of Viral RNA by the Poliovirus RNA Polymerase. PNAS. 1964.  

Viral gastroenteritis around the world causes 200,000 deaths globally each year. Mary Estes talks about her work on 2 gastroenteritis-causing viruses, rotavirus and norovirus, and tells the story of her discovery of the first viral enterotoxin. She also describes how noroviruses have changed from human volunteer studies to studies using “miniguts,” a system now used with many enteropathogenic microorganisms. Julie’s Biggest Takeaways: Rotaviruses and noroviruses kill 200,000 people annually, despite an available rotavirus vaccine and current anti-infective measures. Rotavirus is generally associated with gastrointestinal disease in the very young and the very old, while norovirus infects people at all life stages. Rotavirus is so stable that even when viral samples are extremely dessicated by lyophilization, the samples remain perfectly infectious. Rotavirus stability is largely due to 3 concentric capsid cells. NSP4 is a rotavirus enterotoxin, and the first viral enterotoxin to be discovered. It affects the concentration of the intracellular calcium pools. By activating the calcium chloride channel, NSP4 forces chloride and water to be excreted, directly leading to diarrhea. NSP4 is secreted from infected cells and can also disrupt calcium concentrations of neighboring cells, amplifying the effect of a single infected cell. Rotarix® and RotaTeq® are 2 different attenuated rotavirus vaccines. One contains a single attenuated viral strain while the other contains 5 attenuated viral strains; both vaccines have high efficacy in developed countries and slightly lower efficacy in developing countries. Why vaccine efficacy is lower in developing countries is uncertain, with many hypotheses including microbiome-based effects under study now. Human enteroids, or “miniguts,” offer insight into complex virus-cell interactions. These stem-cell derived miniguts can be generated from different types of animal stem cells, and the enteroids they become reflect the same host-barrier restriction as the animal of origin. The miniguts can be used to culture many sorts of viruses and other microorganisms, such as bacteria and protozoa. Links for this Episode: Mary Estes Website at Baylor College of Medicine Hyser J.M. et al. Rotavirus Disrupts Calcium Homeostasis by NSP4 Viroporin Activity. mBio. 2010. Crawford S.E. et al. COPII Vesicle Transport is Required for Rotavirus NSP4 Interaction with the Autophagy Protein LC3 II and Trafficking to Viroplasms. J Virology. 2019. Ettayebi K. et al. Replication of Human Noroviruses in Stem Cell-Derived Human Enteroids. Science. 2016. In J.G. et al. Human Mini-Guts: New Insignts into Intestinal Physiology and Host-Pathogen Interactions. Nat Rev Gastroenterol Hepatol. 2016. Finkbeiner S.R. et al. Stem Cell-Derived Human Intestinal Organoids as an Infection Model for Rotaviruses. mBio. 2012. Henning S.J. and Estes M.K. Women in Science: Hints for Success. Gastroenterology. 2015. Kapikian A.Z. et al. Visualization of a 27-nm Particle Associated with Acute Infectious Nonbacterial Gastroenteritis. Journal of Virology. 1972. HOM Tidbit: Smith K.N. The Iron Long was just an Engineer’s Side Project. Forbes. 2019. HOM Tidbit: Ramirez M. Living Inside a Canister: Dallas Polio Survivor is One of Few People Left in U.S. Using Iron Lung. Dallas Morning Star. 2018.  

The most abundant organism on Earth lives in its seas: the marine bacterium SAR11. Steve Giovannoni describes how the origins of SAR11 provided its name, and the ways that studying SAR11 have taught scientists about ocean ecology. He also discusses how the different depths of the ocean vary in their microbial compositions and what his big questions are in marine microbiology. Different depths of the ocean have different habitats, but the microbes vary continuously, based in part on light availability: Surface light facilitates photosynthesis by algal cells. These primary producers fix carbon for the entire ecosystem! Because nutrients are readily available, the cell concentration in surface waters can reach nearly 1,000,000 cells/ml. The twilight zone offers dim light. Microbes in this area mainly use carbon sources generated by the surface-dwelling microbes. Below a few hundred meters, cell concentrations drop to 10,000-100,000 cells/ml. The deep ocean has no light and the microbes that live here have significantly different biochemistries and metabolisms. SAR11 is small in both physical size and genome size (0.37–0.89 µm and 1.3 million base pairs, respectively). It is nevertheless the most abundant organism on the planet, with more than 1028 cells estimated to exist worldwide. These cells convert between 6-37% of the carbon fixed in the oceans daily. SAR11 in different niches have ecotypes with different specialties but look physically similar and have very similar genome sequences. Naturally, the most abundant cells in the ocean have the most abundant parasites: bacteriophages called pelagiphages infect SAR11 all over the world. SAR11 and pelagiphages are under constant evolution, though there doesn’t seem to be a CRISPR system in the Pelagibacter genome; these bacteria largely use other mechanisms to evade phage infection. SAR11 is like a house with the lights on all the time, in that the cells constitutively express most metabolic genes. For example, SAR11 metabolizes dimethylsulfoniopropionate (DMSP) into dimethyl sulfide (DMS) and methanethiol (MeSH), which can be produced as soon as the cells are exposed to DMSP. While this may seem energetically expensive, the cells must capitalize on their encounters with this transient resource, often found only at low concentrations, and this capitalization requires the investment of protein production. The cost of metabolic gene regulation outweighs the benefits in this particular case. SAR11 and SAR202 are the poles on the spectrum of heterotrophic marine bacteria. SAR11 is very efficient at accessing and using the organic compounds that come from the phytoplankton (also called the labile organic matter). SAR202, found in the deeper part of the ocean, specializes in hard-to-access carbon compounds that other bacteria can’t access. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Stephen Giovannoni website at Oregon State University OSU High Throughput Microbial Cultivation Lab Carini P. et al. Discovery of SAR11 Growth Requirement for Thiamin’s Pyrimidine Precursor and its Distribution in the Sargasso Sea. ISME J. 2014. Sun J. et al. The Abundant Marine Bacterium Pelagibacter Simultaneously Catabolizes Dimethylsulfoniopropionate to the Gases Dimethyl Sulfide and Methanethiol. Nature Microbiology. 2016. Moore E.R. et al. Pelagibacter Metabolism of Diatom-Derived Volatile Organic Compounds Imposes an Energetic Tax on Photosynthetic Carbon Fixation. Environmental Microbiology. 2019. HOM Tidbit: Sagan L. On the Origin of Mitosing Cells. 1967. HOM Tidbit: Cellmates (Radiolab podcast episode) ASM Article: The Origin of Eukaryotes: Where Science and Pop Culture Collide  

Can a protein be contagious? Jason Bartz discusses his work on prion proteins, which cause spongiform encephalopathy and can be transmitted by ingestion or inhalation among some animals. He further discusses how prions can exist as different strains, and what techniques may help improve diagnosis of subclinical infections. Links for this Episode: Jason Bartz Creighton University website Holec SAM, Yuan Q, and Bartz JC. Alteration of Prion Strain Emergence by Nonhost Factors. mSphere. 2019. Yuan Q et al. Dehydration of Prions on Environmentally Relevant Surfaces Protects Them from Inactivation by Freezing and Thawing. Journal of Virology. 2018. Bartz JC. Prion Strain Diversity. Cold Spring Harbor Perspectives in Medicine. 2016.  Bartz JC. From Slow Viruses to Prions PLoS Pathogens. 2016. Deleault NR, Harris BT, Rees JR, Supattapone S. Formation of native prions from minimal components in vitro. Proceedings of the National Academy of Sciences. 2007. Planet Money Episode 952: Sperm Banks  

Microbial interactions drive microbial evolution, and in a polymicrobial infection, these interactions can determine patient outcome. Deb Hogan talks about her research on interkingdom interactions between the bacterium Pseudomonas and the fungus Candida, 2 organisms that can cause serious illness in cystic fibrosis patients’ lung infections. Her research aims to better characterize these interactions and to develop better diagnostic tools for assessing disease progression and treatment. Links for this Episode: Deb Hogan Lab Website Demers EG et al. Evolution of Drug Resistance in an Antifungal-Naive Chronic Candida lusitaniae Infection. PNAS. 2018. Lewis KA et al. Ethanol Decreases Pseudomonas aeruginosa Flagella Motility through the Regulation of Flagellar Stators. Journal of Bacteriology. 2019. Gifford AH et al. Use of a Multiplex Transcript Method for Analysis of Pseudomonas aeruginosa Gene Expression Profiles in the Cystic Fibrosis Lung. Infection and Immunity. 2016. Grahl N et al. Profiling of Bacterial and Fungal Microbial Communities in Cystic Fibrosis Sputum Using RNA. mSphere. 2018. Microbiology Resource of the Month: The Aeminium ludgeri Genome Sequence HOM Tidbit: https://www.sciencedirect.com/science/article/pii/S0065216408705628 HOM Tidbit: The Frozen Potential of Microbial Collections  

Why is C. diff such a serious disease and what are clinical microbiologists doing to improve patient outcomes with better diagnostic tools?

Many hospital-acquired bacterial infections are also drug-resistant. Amy Mathers describes her work tracking these bacteria to their reservoir in hospital sinks, and what tools allowed her team to make these discoveries. Mathers also discusses her work on Klebsiella, a bacterial pathogen for the modern era. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Nosocomial infections are a type of opportunistic infection: one that wouldn’t normally cause disease in healthy individuals. Once the immune system is compromised due to other infection or treatment, the opportunist bacteria take advantage of the conditions to grow to higher numbers and cause disease. How are different pathogens transmitted in the hospital? Previously, transmission was considered to occur from one patient to a second patient, perhaps via a healthcare worker. When patients from very different parts of the hospital began to come down with the same resistant strain of bacteria, without interacting through the same space or staff, researchers began to look at a different reservoir: the hospital wastewater. How does the bacteria get from the sink to the patients? The bacteria, existing in a biofilm in the pipe right below the drain, can be transferred in droplets when the water is run. These droplets can fall as far as 36 inches from the drain plate and can contaminate the sink bowl or patient care items next to the sink. Some of the solutions to decrease bacterial dispersion from hospital sinks are very simple: for example, offsetting the drain from the tap, which keeps the water from directly running onto the drain, helps decrease the force with which the water hits the drain and therefore decreases bacterial dispersion. The Sink Lab at University of Virginia couldn’t replicate the bacterial growth patterns seen in the rest of the building; in particular, there were fewer protein nutrients that promoted bacterial growth. By setting up a camera observation of sink stations used in the hospital, the team realized that the waste thrown down the sink (extra soda, milk, soup, etc) was feeding the microbial biofilm. This helps the CRE in the biofilms in the sinks thrive. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Amy Mathers website at University of Virginia The Sink Lab at UVA Kotay SM et al. Droplet- Rather than Aerosol-Mediated Dispersion is the Primary Mechanism of Bacterial Transmission from Contaminated Hand-Washing Sink Traps. Applied and Environmental Microbiology. 2018. Mather AJ et al. Klebsiella quasipneumoniae Provides a Windo into Carbapenemase Gene Transfer, Plasmid Rearrangements, and Patient Interactions within the Hospital Environment. Antimicrobial Agents and Chemotherapy. 2018. Kotay S et al. Spread from the Sink to the Patient: in situ Study Using Green Fluorescent Protein (GFP)-Expressing Escherichia coli to Model Bacteral Dispersion from Hand-Washuing Sink-Trap Reservoirs. Applied and Environmental Microbiology. 2016. Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan. Send your stories about our guests and/or your comments to jwolf@asmusa.org.  

How do medical professionals incorporate microbiome science into their patient care? Ami Bhatt discusses her research on the diversity within and between human gut microbiomes, and how this research is slowly and carefully being used to build new patient care recommendations. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Julie’s Biggest Takeaways Although these terms are often used interchangeably, microbiome and microbiota represent distinct samples types: Microbiotarepresents all the organisms that live within a community: archaea, bacteria, viruses, and fungi. Microbiomeis the genomes or transcriptomes of these organisms. The gut microbiota may often be referred to as a single entity, but the gastrointestinal tract has many different niches. Alterations in pH, cell type, and the available nutrients provide different selective pressures for the microorganisms that reside in these conditions. By clustering small proteins based on similarity, Ami’s group was able to identify over 4000 new families of small proteins from existing microbiome datasets. Some of these were found among all microbiome datasets while others were found only in human microbiomes, which provides a clue to their potential housekeeping versus host-microbe-interaction functionality, although the exact functions are still unknown. Outcomes for non-infectious diseases are affected by the gut microbiome. Ami and her colleagues have worked with transplant patients to understand what type of diversity and which strains play a role in best outcome for cancer therapy patients, such as patients receiving bone marrow transplants. Medical doctors are beginning to incorporate new patient care in light of new microbiome studies. Understanding the effects of the gut microbiome on human health have helped slowly change patient care in some settings. For example, doctors are reconsidering recommendations for immunocompromised people to stay away from fresh fruits and vegetables, a recommendation previously made due to the potential risk of patients exposure to pathogenic microbes. The benefit of a wide variety of fiber sources, which promote a diverse and robust microbiome, may turn out to outweigh this risk. Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Ami Bhatt lab website Brewster R. et al. Surveying Gut Microbiome Research in Africans: Toward Improved Diversity and Representation. Trends in Microbiology. Oct 1 2019. Sberro H. et al. Large-Scale Analyses of Human Microbiomes Reveal Thousands of Small, Novel Genes. Cell August 22 2019. Andermann T. et al. The Microbiome and hematopoietic Cell Transplantation: Past, Present, and Future. Biol Blood Marrow Transplant. July 1 2019. Bloomberg: Superbugs Deadlier Than Cancer Put Chemotherapy into Question Clinical Guide to Probiotic Products Available in USA HOM Tidbit: Rous P. A Sarcoma of the Fowl Transmissible by an Agent Separable from the Tumor Cells. Journal of Experimental Medicine. April 1 1911. ASM Article: A Brief History of Cancer Virology

Identified in the 1980s, Borrelia burgdorferi and other Lyme disease-associated spirochetes have since been found throughout the world. Jorge Benach answers questions about Lyme Disease symptoms, his role in identifying the causative bacterium, and his current research on multispecies pathogens carried by hard-bodied ticks. Julie’s Biggest Takeaways Erythema migrans (the classic bullseye rash) is the most common manifestation that drives people to go see the doctor to be diagnosed with Lyme disease, but only about 40% of people diagnosed with Lyme disease experience erythema migrans. Lyme disease can progress to serious secondary manifestations. Why some patients experience these additional disease manifestations, but others do not,  is one of the heaviest areas of study in Lyme disease. Though Borreliadoesn’t have virulence factors that mediate tissue damage, it does avoid the immune system via antigenic variation. When the bacterium is first introduced into a new human host, that person’s immune system generates reactions to the outer membrane components. These bacterial components change over time, leaving the immune response lagging behind and unable to clear the infection. Ixodesticks are the vector for Lyme disease and there are 3 stages in the Ixodestick life: Larvae: the stage during which the tick is most likely to become infected by feeding on a rodent. Nymph: the stage most likely to infect a person (due to their small size, they are less likely to draw attention while feeding). Adult: the stage when the tick develops into a sexual adult; females are most likely to be infected but because female ticks are large, most people will detect and pull out a feeding adult. Ticks feed for 2-4 days; removing a tick in the first 48 hours of attachment decreases the chance for transmission to the patient. Long Island is seeing anecdotal increases of Ambliomaticks (the Lone Star tick), which can transmit the human pathogen Ehrlichia. These anecdotal increases were one of the motivations behind a recently published survey of ticks and the human pathogens they carry. Links for This Episode MTM Listener Survey, it only takes 3 minutes. Thanks! Jorge Benach website at Renaissance School of Medicine Stony Brook University Sanchez-Vicente S. et al. Polymicrobial Nature of Tick-Borne Diseases. mBio. September 10 2019. Monzón J.D. et al. Populaiton and Evolutionary Genomics of Amblyomma americanum, and Expanding Arthropod Disease Vector. Genome Biol Evol. May 2016. ASM Article: The Bulls-Eye Rash of Lyme Disease: Investigating the Cutaneous Host-Pathogen Dynamics of Erythema Migrans Patient Zero podcast HOM Tidbit: Barbour A.G. and Benach J.L. Discovery of the Lyme Disease Agent. mBio. September 17 2019.  

Influenza is famous for its ability to mutate and evolve but are mutations always the virus’ friend? Jesse Bloom discusses his work on influenza escape from serum through mutation and how mutations affect influenza virus function and transmission. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Influenza is famous for its ability to mutate and evolve through two major mechanisms: Antigenic drift occurs when a few mutations accumulate in the influenza genome and lead to seasonal changes. Antigenic shift occurs when two influenza strains recombine their genomes to form one previously unknown in human populations. Avian influenza has caused thousands of zoonotic cases, in which the virus is transmitted from birds to people. This causes serious disease but the virus doesn’t easily pass from person-to-person, limiting how many people are affected. When a zoonotic case becomes easily transmissible between people, as is suspected occurred in the 1918 influenza pandemic, the outcome can be very serious for many, many people. During antigenic drift, the virus accumulates mutations randomly throughout its genome. Mutations in the hemagglutinin (HA) glycoprotein gene are the mutations most likely to affect the ability of antibodies to attach and block HA during viral infection of a new host cell. The circulating human H3N2 influenza A virus accumulates approximately 3-4 mutations annually within its HA gene, representing a 0.5-1% change. On average, it takes 5-7 years of these mutations accumulating until a viral strain can reinfect a previously infected person. The changes in the influenza sequence are responsible for waning immunity against the annually circulating strain. This was demonstrated when a flu strain from the 1950s was inadvertently reintroduced in the 1970s; older people who had previously been infected were protected against this exact same strain. Influenza viruses can escape from sera, which contains many different antibodies, similar to how they can escape from a single monoclonal antibody: through mutations in major antibody binding sites. However, the mutations that allow escape from one person’s serum are different from the mutations that allow escape from another person’s serum. This means the strains that escape one person’s immune system may only be able to infect those with similar immunity.   Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Jesse Bloom’s lab website Guns Germs and Steel by Jared Diamond Lee J.M. et al. Mapping Person-to-Person Variation in Viral Mutations that Escape Polyclonal Serum Targeting Influenza Hemagglutinin.eLife. August 2019. Xue K.S. et al. Cooperating H3N2 Influenza Virus Variants are not Detectable in Primary Clinical Samples.mSphere. January 2018. Francis Arnold at ASM Microbe:Innovation by Evolution: Bringing New Chemistry to Life Let us know what you thought about this episode by tweeting at us @ASMicrobiology or leaving a comment on facebook.com/asmfan.

Graciela Lorca studies genetic systems to find positive and negative microbial interactions that lead to disease. She talks about her discovery of chemical inhibitors for the citrus greening disease bacterium, Liberibacter asiaticus,and how a specific strain of Lactobacillus johnsoniimodulates the immune system and may help prevent development of diabetes in people. Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways Citrus greening disease, or huanglongbing, is a disease of citrus trees causing a major epidemic among citrus farmers around the world. The disease causes trees to sicken and eventually die, and is best diagnosed by PCR amplification of the bacterial DNA from the bacterium that causes the disease, Liberibacter asiaticus. Because the disease spreads through the tree at different rates, it’s important that many samples be tested for accurate diagnosis. Quarantining the disease has proved difficult, as undiagnosed roots can transmit the disease if they are used to hybridize with canopy plants. The disease becomes even harder to contain under bad weather conditions: the high winds of recent hurricanes can scatter the insect vector, the Asian citrus psyllid, leading to infection of new orchards. Although L. asiaticuscan’t be cultured, Graciela performed a screen on L. asiaticustranscription factors that were produced by E. coli. These were tested for inhibition by a chemical library, and discovered that a common treatment for gout, benzbromarone, inhibited protein activity. This discovery was confirmed using in vivoinfected plants and by expressing the gene in related bacterial species, Graciela and her team predict the protein plays a role in responding to osmotic stress. The protein target of the chemical differs widely between citrus greening disease and gout, but the protein-chemical interaction is similar enough to allow protein inhibition. Is there a link between the microbiome and diabetes? 10 years ago, Lactobacillus johnsoniican rescue animals that are predisposed to diabetes. L. johnsoniiinactivates a host enzyme, IDO, which regulates proinflammatory responses. Activated immune cells can travel to the pancreas and attack beta cells, leading to diabetes. Regulating the proinflammatory response by administering L. johnsoniias probiotics offers the opportunity to control development of diabetes in predisposed people.   Links for This Episode MTM Listener Survey, only takes 3 minutes. Thanks! Graciela Lorca’s lab website Pagliai F.A. et al. The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance. PLoS Pathogens. April 2014. Lai K.K., Lorca G.L. and Gonzalez C.F. Biochemical Properties of Two Cinnamoyl Esterases Purified from a Lactobacillus johnsonii Strain Isolated from Stool Samples of Diabetes-Resistant Rats. Applied and Environmental Microbiology. August 2009. Marcial G.E. et al. Lactobacillus johnsonii N6.2 Modulates the Host Immune Response: A Double-Blind, Randomized Trial in Healthy Adults. Frontiers in Immunology. June 2017. HOM Tidbit: Hartmann A., Rothballer M., and Schmid M. Lorenz Hiltner, a Pioneer in Rhisophere Microbial Ecology and Soil Bacteriology Research. Plant and Soil November 2008.