Podcasts about pseudomonas aeruginosa

Matters Microbial #88: Microbial Interactions in Cystic Fibrosis April 24, 2025 Today, Dr. Reed Stubbendieck, Assistant Professor of Microbiology & Molecular Genetics at Oklahoma State University joins the #QualityQuorum to discuss how microbes and the host communicate with one another in the cystic fibrosis lung. Host: Mark O. Martin Guest: Reed Stubbendieck Subscribe: Apple Podcasts, Spotify Become a patron of Matters Microbial! Links for this episode An overview of cystic fibrosis as a disease with a genetic link. A review of the microbiome of the cystic fibrosis lung. An overview of biofilms. An interesting role for extracellular DNA itself as a “building block” of biofilms. An overview of polymicrobial communities. Life in mucus—an interesting essay. An overview of Pseudomonas aeruginosa. Pseudomonas and the siderophore pigment pyoverdin which is not only about iron, but also bacterial conflict and cooperation.   An interesting overview of microbe-microbe interactions, often called “sociomicrobiology,” and an introductory article on this topic. A review of the nasal microbiome. The organism Rothia, understudied and of interest to Dr. Stubbendieck's research group.  Some work from Dr. Stubbendieck's group describing how Rothia is helpful in inhibiting some disease causing bacteria. The organism Dolosigranulum pigrum, also understudied and of interest to Dr. Stubbendieck's research group. More work from Dr. Stubbendieck's group with another possibly probiotic bacterium,  Dolosigranulum pigrum, that may protect against disease causing microbes.  Dr. Stubbendieck's faculty website. Dr. Stubbendieck's very interesting research group website.  Intro music is by Reber Clark Send your questions and comments to mattersmicrobial@gmail.com

Las personas con fibrosis quística son particularmente susceptibles a las infecciones respiratorias, por lo que es importante encontrar tratamientos para estas infecciones. Una revisión Cochrane del Grupo Cochrane de Fibrosis quística y enfermedades genéticas examina la evidencia sobre el uso de antibióticos en personas con esta afección y en este podcast se habla sobre sus hallazgos. Este podcast ha sido traducido por Yasmín García y locutado por Andrea Cervera del Centro Cochrane Iberoamericano.

Las personas con fibrosis quística son particularmente susceptibles a las infecciones respiratorias, por lo que es importante encontrar tratamientos para estas infecciones. Una revisión Cochrane del Grupo Cochrane de Fibrosis quística y enfermedades genéticas examina la evidencia sobre el uso de antibióticos en personas con esta afección y en este podcast se habla sobre sus hallazgos. Este podcast ha sido traducido por Yasmín García y locutado por Andrea Cervera del Centro Cochrane Iberoamericano.

The ‘I' (intermediate susceptibility) in a EUCAST-guided antibiogram never meant impending resistance to your antibiotic. It was never meant to make you find the one ‘S' (invariably a carbapenem) and use it instead—even if many clinicians did. In this episode of Communicable, hosts Marc Bonten and Angela Huttner welcome Profs. Christian Giske (outgoing chair) and Sören Gatermann (newly elected chair) of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) to discuss its recent updates, including the new ‘susceptible dose dependent' (SDD) label, and to shed light on common misconceptions around the way it sets breakpoints. Breakpoints for Pseudomonas aeruginosa are discussed, as are intravenous fosfomycin's ‘disappearance' from the breakpoints table and EUCAST's new guidance on it. Episode peer-reviewed by Dr. Suzanne van Asten of Radboud University Medical Center.Literature:The European Committee on Antimicrobial Susceptibility Testing (EUCAST): https://www.eucast.org/EUCAST guidance on use of fosfomycin i.v. breakpoints:https://www.eucast.org/fileadmin/src/media/PDFs/EUCAST_files/Guidance_documents/Use_of_fosfomycin_iv_breakpoints_General_advice_20240528.pdfIn vitro synergy between fosfomycin and ceftazidime/avibactam: Kroemer, Martens, Decousser et al. Evaluation of in vitro pharmacodynamic drug interactions of ceftazidime/avibactam and fosfomycin in Escherichia coli. J Antimicrob Chemother. 2023 Oct 3;78(10):2524-2534. doi: 10.1093/jac/dkad264

Jenna Jackson we will review mechanisms of resistance, management of multidrug resistant infections, and antimicrobial development.   For more pharmacy content, follow Mayo Clinic Pharmacy Residency Programs @MayoPharmRes. You can also connect with the Mayo Clinic's School of Continuous Professional Development online at https://ce.mayo.edu/ or on X @MayoMedE  

People with cystic fibrosis are particularly susceptible to chest infection. It's important to find treatments for these infections and a Cochrane Review from Cochrane Cystic Fibrosis examines the evidence for the use of antibiotics. Nikki Rowbotham, respiratory paediatrician, who is based in the East Midland in the UK and one of the authors of the June 2023 update of the review, tells us more in this podcast.

People with cystic fibrosis are particularly susceptible to chest infection. It's important to find treatments for these infections and a Cochrane Review from Cochrane Cystic Fibrosis examines the evidence for the use of antibiotics. Nikki Rowbotham, respiratory paediatrician, who is based in the East Midland in the UK and one of the authors of the June 2023 update of the review, tells us more in this podcast.

Host Claire Stinson welcomes you to a special year-end episode of Contagious Conversations focused on highlights from the 2023 season! Listen to selections from the year's episodes on topics as diverse as heath threats facing Black women; training the next generation of public health professionals; and the respiratory triple threat posed by COVID-19, influenza and RSV. Highlights featured include the groundbreaking vaccination approach that led to the eradication of smallpox in 1980; how investigators zeroed in on the cause of an outbreak of a drug-resistant strain of pseudomonas aeruginosa found in contaminated eye drops; the health threats most common to women, and the particular challenges faced by Black women; a conversation with new CDC director Dr. Mandy Cohen; and more. For full episode transcription, visit Contagious Conversations.   Key Takeaways: [1:25] Drs. Bill Foege and Mark Rosenberg codeveloped a project called “Becoming Better Ancestors: Nine Lessons to Change the World”. Dr. Foege talks about his inspiration for this project. [3:09] Dr. Laura Evans discusses the triple threat of COVID-19, influenza and RSV, and shares with the audience her thoughts on how to stay healthy and the importance of vaccines against respiratory threats. [4:37] April was National Minority Health Month and for that occasion Dr. Judy Monroe spoke with Dr. Melody McCloud, an Atlanta-based obstetrician/gynecologist, who shared her insight into the most common health threats women face. [6:22] CDC epidemiologist Dr. Danielle Rankin talks about her role investigating the cause of the outbreak of a drug resistant strain of Pseudomonas Aeruginosa. [7:21] CDC director Dr. Mandy Cohen speaks with Dr. Judy Monroe about the experience she brings to her position and CDC's priorities going forward. [8:59] Drs. Ezekiel Emanuel and Jerome Adams discuss hypertension in America and the risks it poses to almost half of U.S. adults. In this episode, Dr. Adams highlights the ethnic inequities in diagnosing and controlling this silent killer.

In this episode, Emily Heil, PharmD, MS, BCIDP, AAHIVP; Laila Woc-Colburn, MD; and Trevor Van Schooneveld, MD, FSHEA, FACP, discuss their approach to managing infections involving Pseudomonas aeruginosa with difficult-to-treat resistance, including: Mechanisms of β-lactam resistanceEffect of resistance mechanism on susceptibility to antipseudomonal agent2023 IDSA guidance recommendations Activity against newer antipseudomonal β-lactams in the United StatesThe latest clinical data by antimicrobial regimen:              - Ceftolozane/tazobactam              - Ceftazidime/avibactam              - Imipenem/cilastatin/relebactam              - CefiderocolApplying antimicrobial stewardship principlesProgram Director:Trevor Van Schooneveld, MD, FSHEA, FACP  Professor, Division of Infectious DiseasesProgram Director, Infectious Diseases FellowshipMedical Director, Antimicrobial Stewardship ProgramUniversity of Nebraska Medical CenterOmaha, NebraskaFaculty:Emily Heil, PharmD, MS, BCIDP, AAHIVPAssociate ProfessorDepartment of PharmacyUniversity of Maryland  School of PharmacyID Clinical Pharmacy SpecialistUniversity of Maryland Medical Center|Baltimore, MarylandLaila Woc-Colburn, MDAssociate ProfessorDivision of Infectious DiseasesEmory University School of Medicine  Atlanta, GeorgiaContent based on a CME program supported by an educational grant from Merck & Co., Inc., Rahway, NJ, USA.Follow along with a downloadable slideset at: https://clinicaloptions.com/CE-CME/infectious-disease/cmv-prevention-in-sot-recipients/26139Link to full program: https://bit.ly/40HyvPy 

On episode #37 of the Infectious Disease Puscast, Daniel reviews the infectious disease literature for the weeks of 8/31 – 9/13/23. Host: Daniel Griffin and Sara Dong Click arrow to play Download Puscast 037 (22 MB .mp3, 31 min) Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Become a patron of Puscast! Links for this episode Association between varicella zoster virus and dementia (NS) Safety, efficacy, and immunogenicity of V160 vaccine in cytomegalovirus-seronegative women (The Lancet) Microorganisms detected in intussusception cases and controls in children (OFID) Clinician testing and treatment thresholds for management of UTIs (OFID) Clinical outcomes and management of NAAT-positive/toxin-negative Clostridioides difficile infection (CID) Associations of standard care, intrathecal antibiotics, and antibiotic impregnated catheters with cerebrospinal fluid shunt infection (JPIDS) Advances in asynchronous telemedicine call for increased antibiotic surveillance (CID) Two artificial tears outbreak-associated cases of extensively drug-resistant Pseudomonas aeruginosa detected through whole genome surveillance (JID) Pre-XDR congenital TB in an extremely premature baby (CID) Emerging Roles of (1→3)-β-D-glucan in cerebrospinal fluid for detection and therapeutic monitoring of fungal diseases (CID) Outbreak of locally acquired mosquito-transmitted malaria (CDC) Complexity of infectious diseases compared to other cognitive medical subspecialties (OFID) Risk of opportunistic infections associated with long-term glucocorticoid therapies in adults (CID) Music is by Ronald Jenkees

How manageable is multidrug-resistant keratitis? Find out about this and more in today's PV Roundup podcast.

In this episode, David van Duin, MD, PhD, FIDSA, FAST, discusses new data on complicated clinical infections presented at ECCMID 2023, including:Gram-negative resistancePharmacokinetic and clinical outcomes in patients receiving meropenem/vaborbactam for KPC-producing carbapenem-resistant Enterobacterales infectionsComparative study of cefiderocol- vs colistin-containing regimens for CRAB VAP with concomitant bacteremiaReal-world use of imipenem/cilastatin/relebactam for the treatment of infections caused by multidrug-resistant organismsAntimicrobial stewardshipSafety and efficacy of antibiotic de-escalation from an antipseudomonal β-lactam in patients with Enterobacterales BSIs in SIMPLIFYThe SOAB study comparing clinical outcomes of switching to oral antibiotics after IV lead-in therapy vs continuing IV therapy in patients with Enterobacterales BSIsData from REGARD-VAP on outcomes of shortened antibiotic treatment for VAP guided by clinical criteriaInvestigational agentsOpen-label study following ATTACK of patients with colistin-resistant CRAB infections receiving sulbactam/durlobactamSummary of findings from EAGLE-2 and EAGLE-3 of gepotidacin for uncomplicated UTI treatmentPost hoc DOOR analysis of SURE-2 of sulopenem for the treatment of complicated UTIs Faculty: David van Duin, MD, PhD, FIDSA, FAST Professor of Medicine Director, Immunocompromised Host Infecious Diseases Program Division of Infectious Diseases University of North Carolina Chapel Hill, North Carolina Content based on an online CME/CE program supported by an independent educational grant from Shionogi Inc. Link to full program: https://bit.ly/3niXGJ6Link to downloadable slides: https://bit.ly/3Hx0ppn

Dr. Kevin Most of Northwestern Medicine joins the Steve Cochran Show for his weekly roundup of health news. This week, Dr. Most discusses the early signs of all types of cancers, the increased prevalence of autism, and a recent outbreak of candida auris in the U.S. Read Dr. Most's notes below and hear him every Tuesday morning on the Steve Cochran Show. Autism prevalence is Up, but early evaluations fell as pandemic set in, study shows. Findings from  the ADDM network study of 11 communities from 10 states 2.8% of children at the age of 8 were identified to be on some spectrum of the Autism disorder in 2020 The rate in boys is 4% and girls 1% This is up from 2.3% in 2018 There continues to be an increase since 2020, it is unclear if this is the result of more focused evaluations or something else When Covid hit, the evaluations for Autism at ages 4 and 8 decreased, missing the opportunity to identify some individuals at an earlier age For this network in the 6 months before the pandemic 1,593 more evaluations than there had been four years prior, showing increased acceptance for early identification, in the 6 months after the start of the pandemic this pattern reversed and there were 217 less evaluations. Need to get back to increasing the evaluations, as we have shown that early treatment leads to better outcomes. Bacteria in eye drops linked to concerns As of last week, some individuals using eye drops tainted with a drug resistant bacteria had severe consequences Close to 70 individuals ended up with severe infections, 8 were blinded and 3 died The outbreak had been identified in 16 states, including Illinois The cause is a strain of a  highly drug resistant bacteria, Pseudomonas Aeruginosa, never seen in the US before The outbreak was noted in individual who used artificial tears from over 10 different brands Some of the eyedrops were recalled in February from 2 companies EzriCare and Delsam Pharma, The drops for these companies were made in India, where this bacteria is commonly linked to outbreaks CDC is testing unopened bottles to look for contamination Symptoms to look for discharge from the eye, eye pain, redness of the eye, sensitivity to light, blurred vision. These symptoms can be caused by other concerns but should be checked by physician Candida Auris outbreak in US CDC has raised concerns for a spreading fungus in the US Fungus do cause infections but in numbers so much lower than viruses and bacteria, worldwide fungal infections cause about 1.5 million deaths. Too put it in perspective pneumonia causes close to 3 million deaths a year, and that is just infections in the lung Fungus are different than Bacteria and viruses and in most cases cause little health problems, they can be found on our skin and thru out the body, not causing any problems in healthy individuals, however they can be deadly in immunocompromised individuals The specific fungus of concern is a drug resistant Candida Auris strain that was first noted in Japan in 2013 See omnystudio.com/listener for privacy information.

3.26 Pseudomonas Aeruginosa Microbiology review for the USMLE Step 1 Exam Pseudomonas aeruginosa is an encapsulated gram-negative oxidase positive rod that causes a variety of diseases. It can be found in soil, hospitals, and water, and it particularly likes water. P. aeruginosa can enter the body through contact with water, inhalation of respiratory droplets, or by medical equipment. The symptoms of infections caused by P. aeruginosa are caused by the toxins it secretes, including phospholipase C, exotoxin A, and endotoxin. P. aeruginosa causes community-acquired infections such as hot tub folliculitis, otitis externa, lung infections in cystic fibrosis patients, osteomyelitis, and skin infections. It causes nosocomial infections such as ventilator-associated pneumonia and catheter-associated urinary tract infections. P. aeruginosa is associated with skin infections in burn victims

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.01.26.525796v1?rss=1 Authors: Kang, D., Kirienko, N. Abstract: Multidrug-resistant Pseudomonas aeruginosa is a common nosocomial respiratory pathogen that continues to threaten the lives of mechanically-ventilated patients in intensive care units and those with underlying comorbidities such as cystic fibrosis or chronic obstructive pulmonary disease. For over 20 years, studies have repeatedly demonstrated that the major siderophore pyoverdine is an important virulence factor for P. aeruginosa in invertebrate and mammalian hosts in vivo. Despite its physiological significance, an in vitro, mammalian cell culture model to characterize the impact and the molecular mechanism of pyoverdine during infection has only recently been developed. In this study, we adapt a previously-established murine macrophage-based model for human bronchial epithelial cells. We demonstrate that pyoverdine-rich conditioned medium from P. aeruginosa disrupts epithelial integrity in a manner that depends on protease activity and the type II secretion system. Disrupting pyoverdine production, whether genetically or chemically, mitigates this damage. Interestingly, this damage did not require exotoxin A or PrpL (protease IV), two previously-characterized toxins regulated by pyoverdine. We also examined the effects of exposure to purified pyoverdine on lung epithelial cells. While pyoverdine accumulates within cells, the siderophore is largely sequestered inside early endosomes, showing little cytotoxicity. This is in contrast to other, more membrane-permeable iron chelators and siderophores such as pyochelin. However, pyoverdine may indirectly contribute to lung inflammation by potentiating these iron chelators in promoting the production of proinflammatory cytokines. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

In this episode, we review the high-yield topic of Pseudomonas Aeruginosa Infection from the Infectious Disease section. Follow Medbullets on social media: Facebook: www.facebook.com/medbullets Instagram: www.instagram.com/medbulletsofficial Twitter: www.twitter.com/medbullets

In this episode, we review the high-yield topic of Pseudomonas aeruginosa from the Microbiology section. Follow Medbullets on social media: Facebook: www.facebook.com/medbullets Instagram: www.instagram.com/medbulletsofficial Twitter: www.twitter.com/medbulletsIn this episode --- Send in a voice message: https://anchor.fm/medbulletsstep1/message

Drs. Antonio Oliver (@aoliverp73) and Maggie Monogue (@MaggieMonogue) join Dr. Erin McCreary (@Erin McCreary) to discuss all things Pseudomonas aeruginosa. Tune in to learn from some of the best about the complexities of P. aeruginosa resistance, the role of various antibiotics in the management of DTR isolates, and much more! LinkedIn: https://www.linkedin.com/company/sidp/ Learn more about the Society of Infectious Diseases Pharmacists: https://sidp.org/About Twitter: @SIDPharm (https://twitter.com/SIDPharm) Instagram: @SIDPharm (https://www.instagram.com/sidpharm/) Facebook: https://www.facebook.com/sidprx References Shields RK, et al. Clin Infect Dis. 2022;ciac097. doi: 10.1093/cid/ciac097. Check out our podcast host, Pinecast. Start your own podcast for free with no credit card required. If you decide to upgrade, use coupon code r-7e7a98 for 40% off for 4 months, and support Breakpoints.

Infections caused by multidrug-resistant Pseudomonas aeruginosa are considered a major public health problem. Antibiotic options are scarce but new drugs are emerging and more maybe available in the near future. Topics discussed: Pseudomonas aeruginosa as an important pathogen capable of developing resistance to multiple antibiotics Common mechanisms of resistance in Pseudomonas aeruginosa The current and future approaches for these MDR organisms. Guests: Michael Satlin, MD, Associate Professor of Medicine, Pathology and Laboratory Medicine, William Randolph Hearst Foundation Clinical Scholar in Microbiology and Infectious Diseases at Weill Cornell Medical College, New York, NY Alessandra Carattoli, PhD, Professor of Microbiology at the Sapienza University of Rome, Italy. Editor, AAC Visit journals.asm.org/journal/aac to browse issues and/or submit a manuscript.

Hosts Katherine Raspovic and Jacob Wynes have discussions with award winning Systematic Review Format poster authors:    1st Place – Poster No. SR-907: Time to Revision After Periprosthetic Joint Infection in Total Ankle Arthroplasty: A Systematic Review, discussion with poster authors Samantha A. Miner, DPM, AACFAS, and John A. Martucci, DPM, AACFAS 2nd Place – Poster No. SR-902: Functional Outcomes and Complications Associated with Total Talus Arthroplasty: A Systematic Review, discussion with poster author Alex J. Bischoff, DPM 3rd Place – Poster No. SR- 301: Prevalence of Pseudomonas Aeruginosa in Diabetic Foot Infections in the United States: A Systematic Review and Meta-Analysis, discussion with poster author Tyler L. Coye, DPM For more educational resources, visit: https://www.acfas.org/   Release Date: April 26, 2022 Run Time: 12min 27sec

Dr. Cal Ham, a medical officer at CDC in Atlanta, and Sarah Gregory discuss extensively drug-resistant infections linked to medical tourism from the United States to Mexico.

In this episode, Christian Railsback and co-host Dr. Kimothy Smith one another's virtues and conduct a shallow dive into the molecular machinery, persistence, and epidemiology of Pseudomonas aeruginosa, the first of several waterborne pathogens discussed this season. A transcript of the conversation appears below. More about Pseudomonas aeruginosa:Infection risk, spread, and treatmentDrinking water and outbreak surveillance Additional opportunistic pathogens of premise plumbing Stay tuned for more episodes, posting on the first Thursday of each month. Subscribe to our show wherever you get your podcasts and find more info at weebeastiespodcast.com The Wee Beasties podcast is a production of Nephros, Inc., a leading water technology company providing filtration and pathogen detection solutions to the medical and commercial markets. *** SHOW TRANSCRIPT: Christian: I am here with Dr. Kimothy Smith. Kimothy, welcome! Christian: Kimothy, you are currently the Vice President of the Pathogen Detection Systems division at Nephros, but you have a pretty rich history. Can you give our listeners a summary of your professional life and what you're currently working on with Nephros? Kimothy: DVM, PhD, Biodefense, Consulting, Academia/DRI, Nephros, Pathogen Detection in potable water systems. Christian: So, the current technology that Nephros incorporates in its risk management portfolio identifies waterborne pathogens, but there must dozens, possibly hundreds of pathogens to identify? I imagine most people don't know these pathogens by name; maybe they've heard them mentioned, but are likely not acquainted with the specifics -- cellular structure, diseases they cause, target populations which are vulnerable, and recent outbreaks, etc. This series is meant to share information about waterborne pathogens and make otherwise unpalatable information about microorganisms more accessible. Kimothy: Yes, that's right Christian. There is an entire catalog of pathogens and it can get overwhelming quickly. It's difficult to know exactly where to start directing your attention. I thought we might start with pathogens that have been in the headlines as it pertains to outbreaks, but that people aren't screening for or aren't aware is a potential problem at all. Christian: Great; what should we start with? Kimothy: I was thinking Pseudomonas aeruginosa might be a good place to start. Christian: I realize there are other species of Pseudomonas that are important, but, what kind of waterborne pathogen is Pseudomonas aeruginosa and what kind of infection does it cause? Kimothy: This is a gram-negative, opportunistic pathogen, that can infect the blood and lungs and lead to pneumonia. It thrives in moist environments, so soil or water is where it's most commonly found. Christian: I'd like to get to the population of individuals most susceptible to this infection, but before we go there can you give everyone a sense of what type of bug this is at the cellular level? Kimothy: Sure, it's a motile, rod-shaped, gram-negative bacterium. It takes on a blue-green color when grown on a plate and has relatively low nutritional requirements. It can grow anaerobically, which means it does not use oxygen. It also produces a biofilm which combined with its highly adaptive environmental response makes this a fairly resilient bug.  Christian: What do you mean by that? Kimothy: Well, the cell can modify itself very quickly to an antimicrobial environment. The cell's ability to modify its DNA (through mutation or from genes from other bacteria) allows it to resist most anti-microbial climates, while less robust microorganisms will die. The bacteria's efficiency in rapid adaptation combined with being able to obfuscate itself in biofilms makes it very difficult to eradicate. It can also provide a home for other microbes to establish themselves and live. This is why we have seen this bug among the more rapidly trending outbreaks when it comes to nosocomial infections. Christian: Okay, so nosocomial infections? These are infections that are acquired in healthcare environments, like hospitals, clinics, or long-term care facilities? Kimothy: That's right. Christian: Okay, so let's come back to my question from earlier – what kind of population of individuals are most susceptible to acquiring Pseudomonas aeruginosa? Kimothy: Well, the bacterium takes advantage of the vulnerable epithelium (i.e. skin). That is, a patient that has degraded, or underdeveloped epithelial tissue is going to be highly susceptible to Pseudomonas aeruginosa. Babies in the PICU/NICU, for instance, or burn patients in particular. But anyone with a preexisting acute or chronic respiratory issue is also vulnerable. Ironically, since hospitals are where you find antibiotics and antimicrobial agents, antibacterial-resistant Pseudomonas aeruginosa strains find hospitals to be a favorable environment. Medical equipment, such as ventilators or catheters are good locations to harbor Pseudomonas. Christian: I see, so given the persistent and lethal nature of this bug, why are we still seeing it as a problem not being addressed in hospitals and healthcare facilities? For example, we know that if water isn't treated or filtered you can acquire cholera and die, so now we treat or filter the water and don't get sick. Why isn't the same approach taken to address Pseudomonas aeruginosa? Kimothy: Here in the United States, there is not a strict regulatory requirement to test water for pathogens other than for Legionella, so many facilities don't realize they have Pseudomonas aeruginosa in their water supply. Christian: Couldn't facilities just treat or filter the water without screening for it? In other words, isn't it unnecessary to know what's in the water if you implement methods to eliminate nosocomial infections, such as water treatment and filters? Kimothy: I think unfortunately it's slightly more nuanced than what you've described. Just like there is not one or two solutions your physician gives you when you go to the doctor when you're sick, there is no panacea to treat building water networks. Just like a physician, if you want to practice good medicine and develop a sound patient care plan, you need to know what you're dealing with before you start treating. Physicians run blood tests and take images -- x-ray, MRI, etc. We are doing something similar are Nephros. We are taking water samples and testing them using molecular assays and gene sequencing technology. This allows us to have, or give our clients, a clear picture of the building health. Treatment outcomes for the building – filters, UV, chlorine, copper, silver nitrate, etc. – largely depend on what we are diagnosing the problem to be. Christian: So, Pseudomonas aeruginosa, for example, isolated to a burn unit or NICU, may require a more robust remediation strategy for an Infectious Disease staff than say E. coli or addressing certain coliforms? Kimothy: That's right, Christian. And may I add that what we're doing is allowing the screening and diagnosis to occur in the field, on-site, which doesn't confine clients to only using feedback from lab cultures – which can take several days or weeks to get results. Christian: And that's PluraPath you're talking about there, correct? Kimothy: Correct Christian: Alright folks, well that was a nice little overview of Pseudomonas aeruginosa. We'll see you next time for our next Pathogen Podcast here at Nephros. Thanks, Kimothy! Kimothy: You bet; thank you, Christian.

This episode covers pseudomonas aeruginosa!

We hare both very tired, and sometimes we will talk about Pseudomonas in this episode. Theme music is "Lovesick" written and performed by Mors Ontologica.

We hare both very tired, and sometimes we will talk about Pseudomonas in this episode. Theme music is "Lovesick" written and performed by Mors Ontologica.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.22.308627v1?rss=1 Authors: Muthuramalingam, M., Whittier, S., Lovell, S., Battaile, K. P., Tachiyama, S., Johnson, D. K., Picking, W. L., Picking, W. D. Abstract: Many Gram-negative bacterial pathogens use type III secretion systems (T3SS) to inject effector proteins into eukaryotic cells to subvert normal cellular functions. The T3SS apparatus (injectisome) shares a common overall architecture in all systems studied thus far, comprising three major components - the cytoplasmic sorting platform, the envelope-spanning basal body and the external needle with controlling tip complex. The sorting platform consists of an ATPase (SctN) connected to "pods" (SctQ) having six-fold symmetry via radial spokes (SctL). These pods interface with the 24-fold symmetric SctD inner membrane ring (IR) via an adaptor protein (SctK). Here we report the first high-resolution structure of a SctK protein family member, PscK from Pseudomonas aeruginosa, as well as the structure of its interacting partner, the cytoplasmic domain of PscD (SctD). The cytoplasmic domain of PscD forms a forkhead-associated (FHA) fold, like that of its homologues from other T3SS. PscK, on the other hand, forms a helix-rich structure that does not resemble any known protein fold. Based on these structural findings, we present the first model for an interaction between proteins from the sorting platform and the IR. We also test the importance of the PscD residues predicted to mediate this electrostatic interaction using a two- hybrid analysis. The functional need for Arg96 in vivo was then confirmed by monitoring secretion of the effector ExoU. These structures will contribute to the development of atomic-resolution models of the entire sorting platform and to our understanding of the mechanistic interface between the sorting platform and the basal body of the injectisome. Copy rights belong to original authors. Visit the link for more info

Three perspectives on how to approach the treatment of patients with serious MDR Pseudomonas aeruginosa infections. Full manuscript available at: https://accpjournals.onlinelibrary.wiley.com/doi/10.1002/phar.2449

Direto ao Ponto SBPT - Temas em evidência na área respiratória para atualização dos profissionais de saúde. Veja nesta edição: entrevista com o Dra. Fabíola Villac Adde, Pneumologista Pediátrica do Núcleo de Pediatria do Hospital Sírio-Libanês, Doutora em medicina pela Faculdade de Medicina da Universidade de São Paulo, Fellowship na divisão de Pneumologia do Hospital for Sick Children de Toronto no Canadá e também membra do departamento de Pneumologia da Sociedade de Pediatria de São Paulo.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.28.224923v1?rss=1 Authors: Ngo, T. D., Perdu, C., Jneid, B., Ragno, M., Novion Ducassou, J., Kraut, A., Coute, Y., Stopford, C., Attree, I., Rietsch, A., Faudry, E. Abstract: Pseudomonas aeruginosa is an opportunistic bacterium of which the main virulence factor is the Type III Secretion System. The ATPase of this machinery, PscN (SctN), is thought to be localized at the base of the secretion apparatus and to participate in the recognition, chaperone dissociation and unfolding of exported T3SS proteins. In this work, a protein-protein interaction ELISA revealed the interaction of PscN with a wide range of exported T3SS proteins including the needle, translocator, gate-keeper and effector. These interactions were further confirmed by Microscale Thermophoresis that also indicated a preferential interaction of PscN with secreted proteins or protein-chaperone complex rather than with chaperones alone, in line with the release of the chaperones in the bacterial cytoplasm after the dissociation from their exported proteins. Moreover, we disclose a new role of the gate-keeper complex and the ATPase in the regulation of early substrates recognition by the T3SS. This finding sheds a new light on the mechanism of secretion switching from early to middle substrates in P. aeruginosa. Copy rights belong to original authors. Visit the link for more info

Today we'll talk about an organism that can cause everything from pneumonia to turning your nails green. Oh, and we'll make you scared of using hot tubs. --- Send in a voice message: https://anchor.fm/bradleysmicroboardreview/message Support this podcast: https://anchor.fm/bradleysmicroboardreview/support

Merhabalar. Birçok ülkede olduğu gibi, solunum sistemi hastalıkları nedeniyle acil servis başvurularının arttığı aylardayız. Global Initiative For Chronic Obstructive Lung Disease (GOLD) Komitesi 2020 kılavuzunun da yayınlanmasıyla, bu yoğun dönemde bilgilerimizi güncellemek amacıyla acil yönetimiyle alakalı son değişiklikleri gözden geçirelim dedik. İyi okumalar. Öncelikle, bu kılavuzda, en azından acil bakımını etkileyen, çok büyük değişiklikler yok. O yüzden özet bilgilere birkaç güncelleme ekleyeceğim. Temel bilgiler için önceki yazılarımızı (burada ve burada)inceleyebilirsiniz. Tanım ve özet Bu bölümde ufak tefek kelime değişiklikleri hariç, pratiğimizi değiştirecek bir yenilik yok. Birkaç yeni çalışmadan bahsedilmiş : Pseudomonas Aeruginosa kolonizasyonunun, alevlenme nedeniyle artmış hastane yatışı ve mortalite üzerine bağımsız prediktör olduğunun gösterildiği çalışmaya atıfta bulunulmuş​1​. Daha temiz yakıtlara geçilmesi veya maruziyetin azaltılmasının sigara içmeyenlerde KOAH gelişimi riskini azaltabileceğinin gösterildiği çalışmaya atıfta bulunulmuş​2​. Ortamdaki parçacık madde düzeyi ile KOAH prevelansının ilişkili olduğunun gösterildiği çalışmalara atıfta bulunulmuş.​3,4​ Tanı ve Değerlendirme Bilinmesi gerekenler : Dispne, kronik öksürük veya balgam, tekrarlayan alt solunum yolları enfeksiyonu öyküsü ve/veya hastalık için risk faktörlerine maruziyet hikayesi olan tüm hastalarda KOAH göz önünde bulundurulmalı. Tanı için spirometre gerekmekte; bronkodilatörü takiben FEV1/FVC < 0.7 olması dirençli  akımı kısıtlılığını konfirme eder. KOAH değerlendirme hedefleri, hava yolu kısıtlılığının düzeyinin, hastalığın hastanın sağlık durumuna etkisinin ve ilerleyen dönemde gelişebilecek durumların (alevlenme, hastane yatış, ölüm) risklerinin belirlenmesidir. KOAH’ta mortalite ve hastane yatışlarını etkileyebileceğinden, kardiyovasküler hastalıklar, iskelet kası hastalıkları, metabolik sendrom, osteoporoz, depresyon, anksiyete ve akciğer kanseri gibi sıklıkla KOAH’a eşlik eden kronik hastalıklar kontrol altında tutulmalı. Ayırıcı tanı için; 2019’da KOAH-Astım ayırıcı tanısının mevcut görüntüleme ve testlerle yapılmasının mümkün olmadığı belirtilirken, 2020’de bunun “zor” olduğu ifade edilmiş. CRP ve prokalsitoninin alevlenme dönemlerinde antibiyotik kullanımını sınırlandırabileceği, fakat yine de bu tip epizodlarda balgam renginin bakteri yükünü göstermede oldukça duyarlı ve özgül olduğunun gösterildiği bildirilmiş. Başlangıç olarak, eozinofil bakılmasının kortikosteroid kullanımı için başarılı bir kılavuzluk sağladığı çalışmaya atıfta bulunulmuş​5​. Önleme ve idame tedavi Sigaranın bırakılması gerektiği herkesin malumu. Fakat geçen yılda, elektronik sigaralar için “etkinliği ve güvenliği belirsiz” denilse de, geçtiğimiz aylarda bildirilen, ürünlerin içeriğindeki tetrahidrokanabinol, kannabinoid yağları, vitamin E ve diğer bağımlılık yapıcı madde katkıları ile ilgili yayınlar ve  elektronik sigaraya bağlı akut akciğer hasarı, alveolar hemoraji, solunumsal bronşiolit vakalarının patlak vermesi nedeniyle, üzerinin çizilmek üzere olduğunu düşündürdü. Metilksantinlerle ilgili olarak, artmış alevlenme riski altındaki KOAH hastalarında inhale kortikosteroide düşük doz teofilin eklenmesinin, bir yıllık KOAH alevlenme sayısında plasebo ile karşılaştırıldığında, fark oluşturmadığı bildirilen bir çalışmaya atıfta bulunulmuş​6​. (Metilksantinler bir önceki kılavuzda da önerilmiyordu) Kombine bronkodilatör tedavi ile ilgili olarak, uzun etkili B2 agonist/uzun etkili muskarinik agonist ve inhale kortikosgteroid/ uzun etkili B2 agonist tedavilerinin etkinliklerinin benzer olduğu, ancak inhale kortikosgteroid/ uzun etkili B2 agonist verilen hastaların daha yüksek pnömoni riski altında olduğunun gösterildiği bir çalışmaya atıfta bulunulmuş​7​. Daha önceki kılavuzda, >300 hücre/mL kan eozinofil sayısı, inhale kortikosteroid tedavisinden fayda gören hastaların belirlenmesinde eşik ...

In this episode, guest host Dr. David Poetker speaks with Dr. Brad Woodworth and Dr. Do-Yeon. They will discuss the article: In‐vitro evaluation of a ciprofloxacin‐ and ivacaftor‐coated sinus stent against Pseudomonas aeruginosa biofilms. Read the article in International Forum of Allergy and Rhinology Listen and subscribe for free on Apple Podcasts , Google Play […]

A grape jelly smell and greenish blue pigments in an open wound are a sure sign of a serious infection that is hard to cure. Kiara Jeffrey from the 2019 Hiram College Genetics course introduces to the pathogen Pseudomonas aeruginosa.

En el program de esta semana hablamos sobre Pseudomonas aeruginosa y el rol en el tratamiento que tendría el ceftolozano / tazobactam  sobre todo el lo referente a cepas multiresistentes y como los diversos mecanismos de resistencia que este tipo de bacterial puede manifestar pueden afectar la sensibilidad a dicho antimicrobiano. Referencias: A.P Magiorakos y colaboradores. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect. 2012; 18 (3) 268-81. Gabriel Cabot y colaboradores. Pseudomonas aeruginosa Ceftolozane-Tazobactam Resistance Development Requires Multiple Mutations Leading to Overexpression and Structural Modification of AmpC. Antimicrob Agent Chemother 2014; June 58 (6): 3091-9. Pablo A. Fraile-Ribot y colaboradores. Mechanisms leading to in vivo ceftolozane/tazobactam resistance development during the treatment of infections caused by MDR Pseudomonas aeruginosa. J Antimicrob Chemother 2017; 73: 658-663.  Yu Mi Wi y colaboradores. Activity of Ceftolozane-Tazobactam against Carbapenem- Resistant, Non-Carbapenemase-Producing Pseudomonas aeruginosa and Associated Resistance Mechanisms. Antimicrob Agents Chemother 2017; 62 (1).  Andrew Walkty y colaboradores. In vitro activity of ceftolozane/tazobactam versus antimicrobial non-susceptible Pseudomonas aeruginosa clinical isolates including MDR and XDR isolates obtained from across Canada as part of the CANWARD study, 2008–16. J Antimicrob Chemother 2018; 73: 703-708. Tommaso Giani y colaboradores. Italian nationwide survey on Pseudomonas aeruginosa from invasive infections: activity of ceftolozane/tazobactam and comparators, and molecular epidemiology of carbapenemase producers. J Antimicrob Chemother 2018; 73: 664-671. David M. Livermore y colaboradores. Activity of ceftazidime/avibactam against problem Enterobacteriaceae and Pseudomonas aeruginosa in the UK, 2015–16. J Antimicrob Chemother 2018. 73: 648-657.   La Frase de la Semana:   Y esta semana no puede ser sino de Stephen Hawkings debido a queel británico murió este martes (la madrugada del miércoles en Inglaterra), a sus 76 años. Fue uno de los físicos más importantes de la cosmología moderna y se destacó por su teoría sobre agujeros negros y por sus esfuerzos matemáticos para unificar la teoría general de la relatividad de Einstein con los conocimientos emergentes de la física cuántica. La frase dice:  “El peor enemigo del conocimiento no es la ignorancia, es la ilusión del conocimiento”        

People with cystic fibrosis are particularly susceptible to chest infections, some of which can become chronic. It’s important, therefore to try to find treatments for these infections and an updated Cochrane Review from the Cochrane Cystic Fibrosis and Genetic Disorders Group examines the evidence for the use of antibiotics. Alan Smyth, a Coordinating Editor for the Group, based in University of Nottingham in the UK, is one of the authors of this April 2017 review update. He tells us more in this podcast.

Volume 6, Issue 10.Christopher Oermann, MD covers the important topic of the Pseudomonas Eradication in the format of case-study scenarios for the clinical practice.Take our post-test to claim CME credits:Physician post-testNurse post-testTo read a companion newsletter click here.The post Pseudomonas aeruginosa Eradication and Outcomes: Key Questions appeared first on DKBmed Radio. Hosted on Acast. See acast.com/privacy for more information.

Volume 5, Issue 14.In this issue we are joined by Dr. Shawn Aaron of University of Ottawa in Ontario, Canada. Dr. Aaron will discuss infection in patients with optimal therapy of chronic Pseudomonas aeruginosa cystic fibrosis, describe the pathophysiology of pulmonary exacerbations associated with Pseudomonas infection in patients with cystic fibrosis, and evaluate the optimal choice of antibiotics to treat Pseudomonas-associated pulmonary exacerbations in patients with cystic fibrosis.The post Agents for the management of Pseudomonas aeruginosa infection appeared first on DKBmed Radio. Hosted on Acast. See acast.com/privacy for more information.

Timothy Kidd discusses the results of a social network analysis to investigate the spread of Pseudomonas aeruginosa infection in patients with cystic fibrosis. 

Andrea Blanka and Susanne Häussler explain why altered fatty acid metabolism enhances the ability of a disease-associated strain of Pseudomonas aeruginosa to form biofilms.

2014 Doris S. Perpall SURF Speaking Competition Finals. Produced in association with Caltech Academic Media Technologies. © 2015 California Institute of Technology.

Meet Daniel, a three-year-old whose routine throat culture just grew P. aeruginosa, originally presented at the 28th North American Cystic Fibrosis Conference.

Zystische Fibrose ist die häufigste vererbbare letale Erkrankung in Europa, die trotz Fortschritten in Diagnostik und Therapie weiterhin mit einer verkürzten Lebenserwartung einhergeht. Einer der Hauptgründe verfrühter Sterblichkeit betroffener Patienten sind persistierende pulmonale Infektionen mit Pseudomonas aeruginosa. Der Keim bedient sich des Quorum Sensing (QS), eines interbakterielles Kommunikationssystems, um die Ausbildung von Virulenzfaktoren zu regulieren und die Immunantwort des Patienten zu beeinflussen. In dieser Arbeit wurde die Auswirkung des P. aeruginosa QS Moleküls 3oxoC12-HSL auf die Reifung humaner Dendritischer Zellen (DZ) untersucht. DZ vermitteln als professionelle Antigen-präsentierende Zellen zwischen angeborenem und erworbenem Immunsystem. Eine Infektion wurde simuliert, indem humane DZ mit Lipopolysaccharid oder Zytokin-Cocktail aktiviert wurden. Anschliessend wurde die Expression von Maturations- und Migrationsmarkern sowie Zytokinsekretion in Anwesenheit von 3oxoC12-HSL untersucht. Bei LPS-stimulierten DZ kam es in Anwesenheit von 3oxoC12-HSL zu einer erniedrigten Expression der Reifungsmarker CD80, CD86, CD83, CD40, HLA-DR, sowie der Migrationsmarker CD184 (CXCR4) und CD197 (CCR7). Die Coinkubation mit Zytokin-Cocktail und 3oxoC12-HSL ergab eine Herabregulierung der Maturationsmarker CD80, CD86 und HLA-DR. Auf unstimulierte DZ zeigte 3oxoC12-HSL keinen Effekt, das Oberflächenmarker-Expressionsprofil dieser Zellen glich dem unreifer DZ. 3oxoC12-HSL inhibierte auch die Sekretion der pro-inflammatorischer Zytokine IL-12, IFN-gamma, MIP-1alpha, TNF-alpha durch LPS- bzw. Zytokin-Cocktail-gereifte DZ. Insgesamt zeigen unsere Ergebnisse, dass 3oxoC12-HSL die Reifung von DZ unterdrückt und somit das Zustandekommen einer effektiven Immunantwort verhindert wird.

Researchers at Cambridge University announced the discovery of a new way to attack the bacterial "superbug" Pseudomonas aeruginosa, which accounts for 6% of all hospital acquired infections and can be very hard to treat, particularly for patients with lung diseases like cystic fibrosis. Ben Valsler went to meet the man behind the breakthrough, Martin Welch... Like this podcast? Please help us by supporting the Naked Scientists

Researchers at Cambridge University announced the discovery of a new way to attack the bacterial "superbug" Pseudomonas aeruginosa, which accounts for 6% of all hospital acquired infections and can be very hard to treat, particularly for patients with lung diseases like cystic fibrosis. Ben Valsler went to meet the man behind the breakthrough, Martin Welch... Like this podcast? Please help us by supporting the Naked Scientists

Thu, 27 Sep 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/14966/ https://edoc.ub.uni-muenchen.de/14966/1/Eichner_Anja.pdf Eichner, Anja ddc:570, ddc:500, Fakultät für Biologie

Thu, 28 Jun 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/14631/ https://edoc.ub.uni-muenchen.de/14631/1/Kirchner_Fabian.pdf Kirchner, Fabian

eCystic Fibrosis Review: Featured Cases: Exacerbation Therapies

Peter Greenberg, University of Washington, USA speaks on "Sociomicrobiology: Quorum Sensing Circuits in Pseudomonas aeruginosa..". This seminar has been recorded by ICGEB Trieste

Featured Cases: State-of-the-Art Treatment for CF Lung Disease

Fri, 30 Jul 2010 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/11897/ https://edoc.ub.uni-muenchen.de/11897/2/Binder_Tatiana.pdf Binder, Tatiana

Thu, 21 May 2009 12:00:00 +0100 https://epub.ub.uni-muenchen.de/10438/1/Appendix_Hoboth_10438.pdf Hogardt, Michael; Heesemann, Jürgen; Imhof, Axel; Schmold, Sabine; Henke, Chrstine; Eichner, Anja; Hoffmann, Reinhard; Hoboth, Christina

Jeanine Wiener-Kronish, MD, discusses an article published in the September 2008 issue of Critical Care Medicine, titled "Increased mortality of ventilated patients with endotracheal Pseudomonas aeruginosa without clinical signs of infection." Dr. Wiener-Kronish is a professor of research and teaching in anaesthetics and anaesthesia at Harvard Medical School, and Chief of Anesthesia, Massachusetts General Hospital in Boston, (Crit Car Med 2008.36(9): 2495)

BACKGROUND: Eradication of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is possible if initiated early in the course of colonisation. To detect P aeruginosa as early as possible is therefore a major goal. This study was undertaken to validate a commercialised test for the detection of serum Pseudomonas antibodies in patients with CF. METHODS: A representative cross sectional analysis of serum antibodies against three Pseudomonas antigens (alkaline protease, elastase, and exotoxin A) was performed in 183 patients with CF of mean age 16.7 years and FEV1 85.9% predicted. The results were correlated with microbiological results from the previous 2 years to calculate sensitivity, specificity, positive and negative predictive values. The following 2 years were assessed to determine prognostic predictive values. RESULTS: A combination of all three tested antibodies yielded the best results with a sensitivity of 86%, specificity of 96%, and a positive predictive value of 97%. These values were higher if only patients in whom sputum cultures were available were considered (n = 76, sensitivity 95%, specificity 100%, positive predictive value 100%). The prognostic positive predictive value was high in intermittently infected patients (83%) but low in patients free of infection (33%), whereas the prognostic negative predictive value was high in patients free of infection (78%) and low in intermittently infected patients (58%). CONCLUSIONS: Regular determination of serum antibodies may be useful in CF patients with negative or intermittent but not with positive P aeruginosa status. A rise in antibody titres indicates probable infection and eradication treatment may be initiated even in the absence of microbiological detection of P aeruginosa.

Thu, 27 Apr 2006 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/5414/ https://edoc.ub.uni-muenchen.de/5414/1/Schikor_Daniela.pdf Schikor, Daniela ddc:610, ddc:600,

Background: Eradication of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is possible if initiated early in the course of colonisation. To detect P aeruginosa as early as possible is therefore a major goal. This study was undertaken to validate a commercialised test for the detection of serum Pseudomonas antibodies in patients with CF.Methods: A representative cross sectional analysis of serum antibodies against three Pseudomonas antigens (alkaline protease, elastase, and exotoxin A) was performed in 183 patients with CF of mean age 16.7 years and FEV1 85.9% predicted. The results were correlated with microbiological results from the previous 2 years to calculate sensitivity, specificity, positive and negative predictive values. The following 2 years were assessed to determine prognostic predictive values.Results: A combination of all three tested antibodies yielded the best results with a sensitivity of 86%, specificity of 96%, and a positive predictive value of 97%. These values were higher if only patients in whom sputum cultures were available were considered (n = 76, sensitivity 95%, specificity 100%, positive predictive value 100%). The prognostic positive predictive value was high in intermittently infected patients (83%) but low in patients free of infection (33%), whereas the prognostic negative predictive value was high in patients free of infection (78%) and low in intermittently infected patients (58%).Conclusions: Regular determination of serum antibodies may be useful in CF patients with negative or intermittent but not with positive P aeruginosa status. A rise in antibody titres indicates probable infection and eradication treatment may be initiated even in the absence of microbiological detection of P aeruginosa.

Pseudomonas aeruginosa ist ein bedeutender Erreger nosokomialer Infektionen. Besondere Bedeutung erlangt es im Krankheitsverlauf der Cystischen Fibrose. Hier und bei anderen Erkrankungen kann die Expression verschiedener Virulenzfaktoren zu schweren Verläufen führen. Ein Typ-III-Sekretions-positiver Phänotyp, das heißt der Besitz des ExoS-Regulons, ist dabei von prognostischem Wert hinsichtlich Gewebszerstörung, Krankheitsverlauf und Überleben. Bisher ist jedoch wenig über die Regulation des ExoS-Regulon bekannt. Sinnvoll erscheint eine gegensätzliche Expression mit dem Typ-II-Sekretionssytem, da hier zahlreiche degradierende Enzyme sezerniert werden, die auch den Typ-III-Sekretionsapparat beschädigen könnten, und mit der Biofilmbildung, da für Typ-III-Sekretion ein direkter Zellkontakt zur Wirtszelle notwendig ist. Bekannte Regulatoren von Biofilmbildung und Typ-II-Sekretion sind Quorum Sensing, der Sigmafaktor der Stationären Phase (RpoS) und der AlgU-Antisigmafaktor MucA für die Alginatsynthese. In der vorliegenden Arbeit wurden daher ihre Auswirkungen auf die Typ-III-Sekretion untersucht. Hierbei zeigt sich unter Stimulationsbedingungen für Typ-III-Sekretion in vitro und durch Kokulturversuche mit humanen Zellen, daß P. aeruginosa in einem Biofilm nahezu kein ExoS exprimiert. Im Gegensatz dazu werden im Überstand dieser Kokultur größere Mengen an Exotoxin S durch planktonisch wachsende Bakterien erzeugt. Es ließ sich zeigen, daß das rhl-Quorum-Sensing-System von P. aeruginosa die Expression von ExoS und ExoU hemmen kann. Ebenso vermindert der Sigmafaktor der Stationären Phase RpoS die Expression von exoS ebenfalls stark. Die Mutation des AlgU-Antisigmafaktors MucA führt zu einem Anstieg von ExoS in der stationären Phase. Ein möglicher Regulationsweg durch Quorum Sensing besteht in der Aktivierung von ExsD, einem negativen Regulator des ExoS-Regulons. exsD besitzt in der Promotorregion eine Sequenz, die einer lux-Box, das heißt einer Bindungsstelle für die Regulatorproteine (RhlR, LasR) des Quorum Sensing, entspricht. Diese Ergebnisse zeigen, daß die Typ-III-sezernierten Exotoxine durch die oben genannten Faktoren reguliert werden können. Dadurch könnte die Expression des ExoS-Regulons im wesentlichen auf die exponentielle Phase beschränkt und in der stationären Phase und im Biofilm gehemmt werden. Zum anderen kann die verstärkte Expression von Typ-III-sezernierten Exotoxinen bei Mutation des mucA-Genes zur erhöhten Virulenz von mucoiden Isolaten von P. aeruginosa in vivo beitragen.

Featured Cases: Exacerbation Therapies

Featured Cases: State-of-the-Art Treatment for CF Lung Disease