Podcasts about corynebacterium

Dr. Jackie Sherbuk, Assistant Professor of Medicine at the USF Morsani College of Medicine, Division of Infectious Diseases, presents a case-based discussion of gram positive organisms producing disease in humans. Infections discussed include Staphylococcus aureus, Coagulase negative Staphylococcus, Pneumococcus, Streptococcus spp., Enterococcus, Corynebacterium, Bacillus, and Erysipelothrix. Associated clinical syndromes are also discussed.

Warum bestellen Kunden oft eine Scheibe Zitrone zu ihrem Schnitzel? Der Zitronensaft hebt den Geschmack und sorgt für Leichtigkeit. Apropos Geschmack: Die Mikrobe "Corynebacterium glutamicum", die für die Produktion von Natriumglutamat (E 621) sorgt, wurde zur "Mikrobe des Jahres 2025" ernannt. Eine Glosse von Caro Matzko.

In this episode Luis continues going over Corynebacterium. In the last episode he mentioned some media that is used to isolate Corynebacterium diphtheriae. Have you heard of cystine tellurite agar? How about Tinsdale agar? What type of testing is there for the diphtheria toxin?What test systems can identify C. diphtheriae? Tune in to learn more about this organism and how this media works. Questions? Feedback? Send those to letstalkmicro@outlook.comWant to support the podcast? Here's how:Venmo: https://venmo.com/u/letstalkmicroBuy me a Ko-fi: https://ko-fi.com/letstalkmicro

Back to the gram-positive rods! This week Luis goes back to gram-positive rods: Corynebacterium this time. The episode starts with an overview: gram stain, biochemicals, morphology, and species. What do you know about Corynebacterium diphtheriae? Does it always cause diphtheria? What is a pseudomembrane? Tune in and download this episode to learn about this genus that has some species commonly seen in the laboratory.Questions? Feedback? Send those to letstalkmicro@outlook.comWant to support the podcast? Here's how:Venmo: https://venmo.com/u/letstalkmicroBuy me a Ko-fi: https://ko-fi.com/letstalkmicro

Il batterio Corynebacterium diphtheriae, responsabile della difterite, scese minaccioso su Nome e sui più vulnerabili: bambine e bambini.Ancor prima di essere identificato in città, al Maynard Columbus hospital - il dottor Curtis Welch e le infermiere avevano verificato lo stato di conservazione dei farmaci in ospedale.Emerse però una criticità: il siero antitossina contro la difterite era scaduto, reso inutilizzabile dal tempo.Una variabile a cui prestare la massima attenzione che si trasformò in tragedia quando si manifestarono dei casi sospetti proprio nel distretto di Nome.Il Corynebacterium diphtheriae non avrebbe potuto essere contenuto senza l'arrivo del siero, ma con i porti della città ormai inaccessibili a causa del ghiaccio e con gli aeroplani costretti a rimanere a terra per condizioni metereologiche avverse, Nome era completamente isolata da qualsivoglia supporto.E nonostante Welch avesse comunque ordinato un nuovo lotto di siero antitossina, a dicembre del 1924 non era ancora arrivato e mai avrebbe potuto giungere a destinazione, prima della fine dei lunghi mesi invernali.Un periodo insostenibile, soprattutto quando Welch si accorse di uno strano incremento di diagnosi correlate a infiammazione del cavo orale e tonsillite.Tante similitudini che in pochi giorni portarono alla morte delle prime vittime.Soltanto con l'autopsia venne ufficializzato l'allarme: a Nome era appena arrivata la difterite.Contatto mail: andataeritorno.podcast@gmail.comMusic by Epidemic SoundNewsletter: https://andataeritornopodcast.substack.com/

3.09 Corynebacterium Diptheriae Microbiology review for the USMLE Step 1 Exam Corynebacterium diphtheriae is an aerobic gram positive rod that causes diphtheria, commonly spreads through respiratory droplets C. diphtheriae produces an exotoxin called diphtheria toxin which can cause systemic effects by inactivating elongation factor (EF-2) via ADP-ribosylation and shutting down protein synthesis Diphtheria causes fever, sore throat, croup-like cough, pseudomembranous pharyngitis, severe cervical lymphadenopathy, myocarditis and cardiac arrhythmias Cutaneous diphtheria involves ulcerative lesions or cellulitis on the skin that can occur independently of respiratory diphtheria Vaccine available and there are not many cases of it in the US, tends to have an outsized effect on developing countries Risk factors for C. diphtheriae infection include IV drug use, homelessness, and crowded living conditions Treatment involves diphtheria antitoxin and penicillin or erythromycin  

3.02 Bacterial Toxins   Microbiology review for the USMLE Step 1 Exam.   Bacterial toxins are harmful compounds produced by bacteria that cause damage to the host Exotoxins are toxins that are actively secreted by some species of gram positive and gram negative bacteria Examples of exotoxins include botulinum toxin, Corynebacterium diphtheriae toxin, and cholera toxin Endotoxins are toxins that are contained within the cell wall of gram negative bacteria and are released when the bacteria are lysed or fragmented Structurally, endotoxins consist of the O antigen, the core oligosaccharide, and Lipid A, with the Lipid A component being responsible for most of the toxicity Endotoxins are less virulent and more heat stable than exotoxins, and are usually contained in the bacteria's own genetic material rather than on a plasmid

Layda Rincon, an epidemiologist with the Cameron County Public Health Department in Texas, and Sarah Gregory discuss a case of toxigenic Corynebacterium diphtheriae infection in a pet cat.

Dr. Jacqueline Sherbuk, Assistant Professor at the Morsani College of Medicine Division of Infectious Diseases, presents a review on several important classes of clinically significant gram-positive bacteria. Dr. Sherbuk begins by discussing Staphylococcus aureus, MRSA, and Coagulase negative Staphylococci and some of the clinical syndromes they can cause. Next, Dr. Sherbuk introduces Streptococcus pneumonia and the syndrome of invasive pneumococcal disease. Then, Group A strep pyogenes, the viridans streptococci, and the variant streptococci are related. Also presented are Enterococcus faecalis and vancomycin resistant enterococcus faecium. Lastly, Dr. Sherbuk references Corynebacterium spp., Listeria, Bacillus, and Erysipelothirx spp.

In this episode, we review the high-yield topic of Corynebacterium diphtheriae 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

In this episode we continue exploring the realm of Gram positive bacilli. Jame and Callum discuss Listeria, Lactobacillus and Erysipelothrix. These complete the "non-branching GPBs" we are discussing, along with Bacillus and Corynebacterium.Send suggestions to idiotspodcasting@gmail.com

In this episode we continue exploring the realm of Gram positive bacilli. Jame and Callum discuss Corynebacterium looking at Diptheroids and Diptheria and explaining the difference.We're going to spend the next few episodes talking about Gram positive Bacilli and the infections they cause.Send suggestions to idiotspodcasting@gmail.com

 Garbing and Behavior Considerations for Those Servicing USP 797 Customers Podcast with Abby Roth from Critical Point Nearly every certification company Abby has worked with has at some point had viable results come back from the lab that are off the charts. It may be something like 120 CFU/m3 of Staphylococcus, Micrococcus, and Corynebacterium species on a sample; and the counts are similar for all buffer and ante-room results. When you receive results like this, two thoughts will likely run through your mind. First, wow they are a mess! And second, oh wait, what if this was from us? You are going to have to share the results with the customer regardless of the cause. But first, you will want to determine if the exceeded results were due to poor garbing or behavior practices or sampling errors on your end. This way, when you discuss the results with your customer, you are prepared to share the corrective actions your organization is taking to prevent issues like this in the future.How to Integrate Compliance Procedures into Business Activitieshttps://www.buzzsprout.com/1794777/8670285How To Integrate Compliance Issues Into Business Activities: Part 2https://www.buzzsprout.com/1794777/8713586Support the show

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Learn about why you shouldn’t add oil to your pasta water; a simple way to help kids think better; and why your dog’s paws smell like corn chips. Here's Why You Shouldn't Add Oil to Your Pasta Water by Ashley Hamer Helmenstein, A. M. (2019). Why Don’t Oil and Water Mix? ThoughtCo. https://www.thoughtco.com/why-oil-and-water-dont-mix-609193  ‌Corriher, S. (2007, April 10). Cooking Pasta Properly. FineCooking; FineCooking. https://www.finecooking.com/article/cooking-pasta-properly  ‌Pantry Raid I: Use Your Noodle Transcript. (2010). Goodeatsfanpage.com. http://www.goodeatsfanpage.com/season1/pasta/pastatranscript.htm  This Reminder Brings Out Flexible Thinking in Kids by Alison Jones Jones-Duke, A. (2019, July 5). This reminder brings out flexible thinking in kids. Futurity. https://www.futurity.org/reminders-children-roles-flexible-thinking-2099002-2/  ‌Gaither, S. E., Fan, S. P., & Kinzler, K. D. (2019). Thinking about multiple identities boosts children’s flexible thinking. Developmental Science, 23(1). https://doi.org/10.1111/desc.12871  Here's why your dog's paws smell like corn chips by Grant Currin Reactions. (2020). Why Do My Dog’s Paws Smell Like Fritos? [YouTube Video]. In YouTube. https://www.youtube.com/watch?v=30_QRAC6XOU&feature=youtu.be  Dove, L.L. (2016, November 14). Why Your Dog’s Paws Smell Gloriously Like Corn Chips. HowStuffWorks. https://animals.howstuffworks.com/pets/why-dog-paws-smell-fritos-corn-chips.htm   Soniak, M. (2010, July 12). Why Do Your Dog’s Feet Smell Like Popcorn? Mentalfloss.com. https://www.mentalfloss.com/article/25030/why-do-your-dogs-feet-smell-popcorn  Subscribe to Curiosity Daily to learn something new every day with Cody Gough and Ashley Hamer. You can also listen to our podcast as part of your Alexa Flash Briefing; Amazon smart speakers users, click/tap “enable” here: https://www.amazon.com/Curiosity-com-Curiosity-Daily-from/dp/B07CP17DJY  See omnystudio.com/listener for privacy information.

Microbiology-- corynebacterium diphtherium-- lab diagnosis --eleks gel ppt test --uses of eleks gel ppt test --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app

Pathogenesis of gram +ve non spore forming rod --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app

Microbiology-- Gram +ve non sporing rod shaped bacteria --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app

Though it's a less common form of psoriasis, Inverse Psoriasis (IP) impacts about 30% of those living with Plaque Psoriasis. One thing about having Inverse Psoriasis that really caught my attention was the connection to getting fungal infections at the site of IP rashes! I always ask clients regardless of what their main concern is if they have had issues with fungus or yeast in other areas of the body. And it's not uncommon for me to find that fungal issues elsewhere tend to match up to having fungal overgrowth in the gut. I wanted to share my alternative perspective on Inverse Psoriasis so that if you're struggling with it (or you know someone who is), you can use it as a clue! You don't have to feel embarrassed or live in shame about it because knowing that IP is present could help you identify other issues driving your psoriasis under the surface. In this episode: What is inverse psoriasis? Candida + other bacteria that make IP worse Conventional ways IP is addressed Shocking candida stat that all Psoriasis warriors should know Alterative thoughts on IP + where to dig deeper Quotes: One study found that 56.6% of Inverse Psoriasis rashes had Corynebacterium minutissimum present making symptoms worse. A 2018 paper found that the “prevalence of Candida spp. colonization was significantly higher in patients with psoriasis compared with the control group.”

Today we'll talk about the bacterium that makes you want to shake maracas! Corynebacterium diphtheriae High-yield, board-relevant information with board-style practice questions. --- Send in a voice message: https://anchor.fm/bradleysmicroboardreview/message Support this podcast: https://anchor.fm/bradleysmicroboardreview/support

Bună ziua. Eu sunt Elena Cioina și vă invit să ascultați un nou episod al podcastului „Sănătos Informațional”. Astăzi vorbim despre difterie, o boală infecțioasă destul de periculoasă, care se transmite foarte repede și pe distanțe foarte mici. Se răspândește cel mai des în încăperile închise, unde nu se aerisește sau nu se păstrează curățenia sau se află o persoană deja bolnavă. Te poți molipsi ușor, dacă ai fost în contact cu un purtător al bacteriei Corynebacterium diphtheriae și nu ești vaccinat, dacă ai pus mâna pe o suprafață contaminată, dacă cineva bolnav a tușit, strănutat lângă tine. Difteria afectează în mod special căile nazale, faringele, laringele și pielea, iar ulterior și alte organe interne. Este o urgență medicală și se tratează doar în staționar. Epidemiologii spun că singura metodă de prevenire a bolii este vaccinarea. Autoritățile din Ucraina au înregistrat în ultimele 2 luni peste 20 de cazuri de difterie. Cele mai multe în regiuni aflate la granița cu România și Moldova. Primul caz a fost important din India, țară endemică la difterie. Ucraina este afectată de infecție, spun epidemiologii, din cauza ratei mici de vaccinare a populației. Doar 40%-60% din populația acestei țări are vaccinul administrat împotriva difteriei, insuficient pentru o protecție de grup sau pentru protejarea celor cu contraindicații la vaccinare. România este și ea în alertă, chiar dacă nu au fost înregistrate cazuri. Și la ei rata de vaccinare împotriva difteriei este sub nivelul optim de protecție colectivă. Autoritățile au declarat stare de alertă și au demarat o campanie de informare și vaccinare, mai ales a populației din localitățile megieșe cu Ucraina. Alături de India, la nivel global, difteria are o incidență mare în Indonezia, Yemen, Nigeria și în Venesuela. Cazuri de difterie au fost constate și în Europa. Anul trecut au fost înregistrate 26 de cazuri în Germania, 15 cazuri în Marea Britanie, 10 în Ucraina. În Moldova situația e mai bună, spun specialiștii în imunizări. Potrivit Agenției Naționale pentru Sănătate Publică, acoperirea vaccinală a copiilor este între 90-95%. Mai prost la acest capitol stau adulții. Doar 75% din cetățenii moldoveni adulți sunt vaccinați împotriva difteriei. Nevaccinați sunt în mod special emigranții, a căror evidență e complicat să o ții, afirmă specialiștii de la ANSP. Despre difterie, simptome, importanța imunizării, tratament, ne paște sau nu pericolul izbucnirii unui focar sau chiar epidemii de difterie am vorbit astăzi cu Anatol Melnic coordonatorul Programului național de imunizări, șef al secției supraveghere epidemiologică a bolilor prevenibile prin vaccinare de la Agenția Națională pentru Sănătate Publică.

This episode: A stable community of only 7 bacteria around corn roots take on similar functions to the much more diverse soil community! Download Episode (12.5 MB, 13.75 minutes) Show notes: Microbe of the episode: Corynebacterium insidiosum Journal Paper: Niu B, Paulson JN, Zheng X, Kolter R. 2017. Simplified and representative bacterial community of maize roots. Proc Natl Acad Sci 114:E2450–E2459. Other interesting stories: Gut community correlates with inflammatory bowel disease treatment effectiveness Bacteria-produced hydrogen in soil could feed other plant-benefiting microbes (paper) Engineered bacteria could treat genetic disease by digesting things for people who can't (paper) Engineered cancer-killing virus also delivers therapy directly to tumors (paper) Using microbes to create clothing that adapts in color and ventilation (paper)   Post questions or comments here or email to bacteriofiles at gmail dot com. Thanks for listening! Subscribe: iTunes, RSS, Google Play. Support the show at Patreon, or check out the show at Twitter or Facebook

Corynebacterium glutamicum is a Gram positive soil bacterium with high industrial importance in ton scale production of amino acids. Apart from that, it becomes more and more important for medical studies, where it serves as model organism due to its close relation to bacteria causing several pathogens such as tuberculosis, diphtheria and leprosy. C. glutamicum, like Mycobacterium tuberculosis, has a distinct cell wall which is composed of a peptidoglycan layer (murein) with covalently bound polysaccharide layers that are capped with mycolic acids. In addition, both organisms have a polar cell wall synthesis machinery which is spatially regulated by DivIVA (Wag31 in M. tuberculosis). The present study shows that DivIVA regulates cell wall synthesis upon direct interaction with the lipid II flippase RodA. RodA determines morphology and growth in C. glutamicum and is localized to the poles and septa. The absence of rodA results in growth defects and cell shape alterations as well as altered lipid II proliferation of the poles (polar cell growth is sustained). DivIVA is furthermore involved in chromosome segregation upon direct interaction with the partitioning ParB protein, which binds to parS sites on the chromosome, thus tethering the replicated nucleoids to the cell poles. Interactions of DivIVA with ParB and RodA were identified in a synthetic in vivo protein-protein interaction assay where fluorescently labeled proteins of interest are expressed in E. coli cells and interaction is analyzed microscopically. A decisive improvement of this assay is the application of FRET, which is more sensitive and allows quantification of interaction. In order to test whether ParB and RodA compete for the same interaction site in DivIVA, we mapped interaction sites of both proteins. It turned out that ParB binds to a middle region of DivIVA, whereas RodA binds to the N-terminal domain of DivIVA where one lysine residue is essential for interaction. To fight bacterial infections, that cause thousands of casualties each year, it is mandatory to understand mechanisms in cellular processes, such as cell division and growth, to find new targets for antibiotic intervention. Unfortunately, bacteria are able to develop resistances against many antibiotics. The mycolic acid or arabinan layer and synthesis machinery are good candidates for new antibiotics. Amongst others, two of them have emerged as useful drugs against M. tuberculosis, ethambutol (EMB) and BTZ043. In this study, we investigated the modes of action and antibiotic susceptibility of C. glutamicum after EMB and BTZ043 treatment. We found that both antibiotics, which target the arabinan synthesis pathway, affect exclusively polar elongation growth, as demonstrated in different staining assays. Interestingly, only 10% of the cells were killed and cells in stationary phase were not affected by EMB or BTZ043. Moreover, we used a chromosomal DivIVA-mCherry fusion and found that DivIVA protein level is drastically increased. The cells show asymmetric recovery after treatment, in which one daughter cell acquires the excess DivIVA whereas the other daughter cell exhibits normal cell growth.

Background: Toxigenic Corynebacterium ulcerans can cause a diphtheria-like illness in humans and have been found in domestic animals, which were suspected to serve as reservoirs for a zoonotic transmission. Additionally, toxigenic C. ulcerans were reported to take over the leading role in causing diphtheria in the last years in many industrialized countries. Methods: To gain deeper insights into the tox gene locus and to understand the transmission pathway in detail, we analyzed nine isolates derived from human patients and their domestic animals applying next generation sequencing and comparative genomics. Results: We provide molecular evidence for zoonotic transmission of C. ulcerans in four cases and demonstrate the superior resolution of next generation sequencing compared to multi-locus sequence typing for epidemiologic research. Additionally, we provide evidence that the virulence of C. ulcerans can change rapidly by acquisition of novel virulence genes. This mechanism is exemplified by an isolate which acquired a prophage not present in the corresponding isolate from the domestic animal. This prophage contains a putative novel virulence factor, which shares high identity with the RhuM virulence factor from Salmonella enterica but which is unknown in Corynebacteria so far. Furthermore, we identified a putative pathogenicity island for C. ulcerans bearing a diphtheria toxin gene. Conclusion: The novel putative diphtheria toxin pathogenicity island could provide a new and alternative pathway for Corynebacteria to acquire a functional diphtheria toxin-encoding gene by horizontal gene transfer, distinct from the previously well characterized phage infection model. The novel transmission pathway might explain the unexpectedly high number of toxigenic C. ulcerans.

Sat, 11 Feb 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/14080/ https://edoc.ub.uni-muenchen.de/14080/1/Boschert_Verena.pdf Boschert, Verena

Fri, 9 Feb 2007 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/6620/ https://edoc.ub.uni-muenchen.de/6620/1/Lenz_Andrea.pdf Lenz, Andrea

Stämme der Spezies Arcanobacterium (A.) pyogenes gelten allgemein als empfindlich gegenüber Penicillinen. Hauptsächlich aus diesem Grund gibt es bisher keine etablierte Methode zur Empfindlichkeitsbestimmung von A. pyogenes. Im Rahmen dieser Arbeit wurde für A. pyogenes eine Methode zur Bestimmung der Minimalen Hemmkonzentration (MHK) mittels Bouillonmikrodilution erarbeitet, die sich an der Vorgehensweise des CLSI (Clinical and Laboratory Standards Institute, USA)-Dokumentes M31-A2 orientiert. Mit Hilfe der erarbeiteten Methode wurden die MHK-Werte zweier Bakterienkollektive mit insgesamt 115 Bakterienstämmen [53 süddeutsche Isolate sowie 62 deutschlandweit im Rahmen eines Monitoringprogramms (Bft-GermVet) gesammelte Stämme] bestimmt. Zusätzlich wurde die genetische Grundlage der dabei häufig zu beobachtenden Tetracyclinresistenz untersucht. Bei Anwendung der vom CLSI-Dokument empfohlenen Verdünnung der Bakteriensuspension im Medium im Verhältnis 1:200 wurde die Inokulumsdichte von A. pyogenes im Vergleich zum vorgeschriebenen Dichtebereich etwa um das Dreifache über-schritten. Daher wurde eine Verdünnung im Verhältnis 1:667 vorgenommen, wodurch valide Inokulumsdichten erreicht wurden. In der vom CLSI-Dokument empfohlenen kationenadjustierten Müller-Hinton-Bouillon (CaMHB) konnte ohne weitere Zusätze kein ausreichendes Bakterienwachstum erreicht werden, unter Zusatz von 2 % fetalem Käl-berserum (FKS; aufgrund des Vorhandenseins von Thymidin nur für die Testung nicht-sulfonamidhaltiger Antibiotika verwendbar) oder 2 % lysiertem Pferdeblut konnte die MHK nach 24 Stunden gut abgelesen werden. Aerob (von der CLSI-Norm empfohlen) und unter Zusatz von 3 Vol% CO2 bebrütete Mikrotiterplatten wiesen nach 24 Stunden keine relevanten Unterschiede in der MHK der untersuchten Wirkstoffe auf. Aufgrund der besseren Ablesbarkeit wurde der Inkubation unter Zusatz von CO2 der Vorzug gegeben. Die aus dem süddeutschen Raum stammenden A. pyogenes-Stämme wurden hinsichtlich ihrer Resistenz gegenüber Tetracyclin, Penicillin G und Erythromycin untersucht. Im Rahmen des BfT-GermVet-Projekts wurden die Isolate auf ihre Empfindlichkeit gegenüber 24 verschiedenen Wirkstoffen geprüft. Eine qualitative Bewertung als „resistent“ oder „sensibel“ konnte anhand der im Dokument M31-A2 vorhandenen Grenzwerte nur für wenige Wirkstoffe (Amoxicillin/Clavulansäure, Cephalothin, Tetracyclin, Chloramphenicol, Sulfa-methoxazol/Trimethoprim, Sulfamethoxazol; Ampicillin und Penicillin unter Vorbehalt) vorgenommen werden. Gegenüber den getesteten β-Lactam-Antibiotika, Aminoglykosiden, Fluorchinolonen und Phenicolen wurden generell niedrige MHK-Werte beobachtet, die - soweit Grenzwerte vorhanden waren - im sensiblen Bereich lagen. Bei der Testung von Sulfonamiden und potenzierten Sulfonamiden kam es zu großen Unterschieden zu früheren Studien, was jedoch eher auf methodische Unterschiede zurückzuführen ist als auf Änderungen der Resistenzraten. Gegenüber Sulfamethoxazol/Trimethoprim waren alle Stämme empfindlich, gegenüber Sulfamethoxazol waren die porcinen Isolate ebenfalls empfindlich, die bovinen Stämme wiesen je nach Indikation eine Resistenzrate von 24 bis 32 % auf. Insgesamt waren 9,5 % der untersuchten Isolate resistenzverdächtig gegenüber Makrolid-Antibiotika. Diese im Vergleich zur Literatur niedrige Zahl ist entweder durch die unterschiedlichen Isolatzahlen bedingt oder tatsächlicher Ausdruck eines Resistenzrückgangs, der mit dem Verbot von Tylosin als Futtermittelzusatzstoff in den 1990er Jahren assoziiert sein könnte. Bei der Untersuchung von Tetracyclin erwiesen sich unabhängig von der Tierart über 60 % der Isolate als resistenzverdächtig, wobei die MHK90 beim Schwein bei 8 µg/ml und beim Rind bei 64 µg/ml lag. Bei der genetischen Untersuchung von 36 tetracyclinresistenten Isolaten aus Süddeutschland auf das Vorkommen von acht verschiedenen tetracyclinresistenzvermittelnden Genen konnte bei 66,7 % der Isolate das für ein ribosomales Schutzprotein kodierende Resistenzgen tet(W) detektiert werden, das in der Literatur als hauptverantwortlich für die Tetracyclinresistenz bei A. pyogenes gilt. Neben diesem konnte auch die strukturelle Einheit eines für ein Effluxprotein kodierenden Gens, tet(33), bei 22,2 % der Isolate nachgewiesen werden. Bei keinem Stamm konnte tet(33) ohne gleichzeitig vorhandenes tet(W) isoliert werden. Die in der Literatur beschriebene Lokalisation von tet(33) auf einem Plasmid konnte für die untersuchten Stämme nicht bestätigt werden. Bei allen tet(W)- und tet(33)-positiven Isolaten handelte es sich um Stämme boviner Herkunft. Der MHK-Wert der tet(W)-positiven Isolate lag zwischen 8 und 64 µg/ml, die Mehrheit der Stämme hatte eine MHK von 16 µg/ml. In Anwesenheit von tet(33) lag die MHK bei sieben von acht Isolaten bei 32 µg/ml, ein Isolat wies eine MHK von 64 µg/ml auf. Bei einem Isolat boviner Herkunft (4371-03), bei dem weder tet(W) noch tet(33) detektiert werden konnte, konnte erstmals für Arcanobakterien die regulatorische Einheit des Gens tet(Z), das bisher nur bei Corynebacterium glutamicum beschrieben wurde, identifiziert werden. Das Strukturgen tetA(Z), das ebenfalls für ein Effluxprotein kodiert, konnte nur partiell nachgewiesen werden. Es ist daher nicht bekannt, ob die bei 4371-03 beobachtete MHK von 8 µg/ml auf das identifizierte tet(Z) zurückzuführen ist. Insgesamt blieben elf Isolate einschließlich aller Stämme porciner Herkunft (N = 8) ohne zugeordnete tet-Determinante.

1. Der Aufbau des Membranpotentials und die ATP-Synthese in H. halophilus wurden durch Cl- nicht beeinflußt. Zusammen mit den Ergebnisse früherer Studien gibt es keinen Hinweis darauf, daß Cl- an der primären Bioenergetik von H. halophilus beteiligt ist. 2. Es wurde ein unter Hochsalzbedingungen induziertes, Cl--abhängiges Transportsystem für das kompatible Solut Betain identifiziert und charakterisiert. Dieses System transportiert Betain mit einer maximalen Geschwindigkeit von Vmax.= 14,0 ± 0,2 nmol/min x mg Protein und hat einen Km-Wert für Betain von 72,8 ± 10,4 µM. Die Ergebnisse der durchgeführten Hemmstoffstudien deuten darauf hin, daß die Betain-Aufnahme in H. halophilus über einen primären Transportmechanismus erfolgt. 3. Die Beweglichkeit von H. halophilus auf Weichagarplatten zeigt eine klare Cl--Abhängigkeit. In elektronenmikroskopischen Untersuchungen konnte festgestellt werden, daß die Flagellenbildung in H. halophilus Cl--abhängig ist. Das Flagellin wurde gereinigt, und es wurde ein spezifisches Antiserum dagegen hergestellt. 4. Immunologische Analysen ergaben, daß die Synthese des Flagellins Wachstumsphasen-abhängig war. In der log-Phase und in der frühen stationären Phase wurden große Mengen an Flagellin nachgewiesen, während die Flagellinkonzentration in der späten stationären Phase zurückging. Interessanterweise war die Flagellinsynthese zu jedem Zeitpunkt des Wachstums Cl--abhängig; in Abwesenheit von Cl- war kein Flagellin nachzuweisen. Dies ist der erste Nachweis einer Cl--abhängigen Proteinproduktion in einem Prokaryonten. 5. Es wurde eine Plasmid-Genbank aus chromosomaler DNA von H. halophilus generiert, die 5807 Klone mit einer durchschnittlichen Fragmentgröße von 4415 Bp enthält. Dies entspricht einer Wahrscheinlichkeit von 99,8%, daß sämtliche Bereiche des Genoms von H. halophilus abgedeckt wurden. Die für das Flagellin (fliC) und die β-Untereinheit der F1FO-ATP-Synthase (atpD) aus H. halophilus kodierenden Gene wurden mit Hilfe von Koloniehybridisierungen in der Genbank identifiziert. Anschließend wurden Teile dieser Gene kloniert und sequenziert. 6. Northern-Blot- und RT-PCR-Analysen zeigten, daß die Transkription von fliC durch Cl- um den Faktor 2 stimuliert wird. Dies ist der erste Nachweis einer durch Cl- stimulierten Transkription eines Gens mit bekannter Funktion. 7. Versuche zur Substitution von Cl- durch kompatible Solute ergaben, daß Glutamat, Succinat und Fumarat die Cl--Abhängigkeit des Wachstums von H. halophilus aufheben können. Für Glutamat wurde gezeigt, daß dies auf die nicht Cl--abhängige Aufnahme von Glutamat zurückzuführen ist. Für die Beweglichkeit und die Flagellinsynthese wurde gezeigt, daß Glutamat Cl- nicht effektiv substituieren kann. 8. Mit Hilfe von 2D-gelelektrophoretischen Studien konnten 5 weitere Cl-- abhängig synthetisierte Proteine in H. halophilus nachgewiesen werden. Die Identifizierung dieser Proteine erfolgte durch N-terminale Sequenzierung und nachfolgender Suche nach ähnlichen Proteinen in Datenbanken. Zwei davon, YvyD und SodA, gehören zum σB-Regulon von B. subtilis. YvyD ist von besonderem Interesse, da es als σ-Faktor modulierendes Protein an der Cl-- abhängigen Signaltransduktionskette, die von der Wahrnehmung des Reizes zur Genexpression führt, beteiligt sein könnte. Ein drittes Protein (YhfK) ist Aspartatund Glutamat-Semialdehyd-Dehydrogenasen sehr ähnlich. Das vierte Protein ist der ATP-bindenden Untereinheit verschiedener ABC-Transporter sehr ähnlich. Das fünfte identifizierte Protein, LuxS, ist in Gram-negativen an der Biosynthese von Autoinduktoren beteiligt. 9. Teile der Gene, die in H. halophilus für YvyD bzw. LuxS kodieren, wurden mit Hilfe von degenerierten Oligonukleotiden per PCR amplifiziert, kloniert und sequenziert. 10. In Wachstumsversuchen konnte gezeigt werden, daß 11 von 44 darauf untersuchten Arten Gram-positiver und Gram-negativer Bakterien eine Cl-- abhängige Osmotoleranz aufweisen. Dies waren: Aeromonas hydrophila, Bacillus megaterium, Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Paracoccus denitrificans, Proteus mirabilis, Proteus vulgaris, Staphylococcus aureus, Thermus thermophilus und Vibrio fischeri.