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17 Cards in this Set
- Front
- Back
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Group D pathogens are what?
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Enterococcus and S. suis - this is his final word on the matter
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What bacteria are in the mycolic acid-based cell envelope?
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Corynebacterium, Arcanobacterium (?),
Rhodococcus, Mycobacterium |
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What is the special power that mycolic acid cell envelopes instills these bacteria with?
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Corynebacterium, Arcanobacterium (?),
Rhodococcus, Mycobacterium It makes some of them acid fast. Corynebacteria are not acid fast because their fatty acid chain (of mycolic acids) are too short. Nocardia and Mycobacteria are. |
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Tell me some things about Corynebacteriae.
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C. diphtheriae- “chinese
letter” pattern of microorganisms.! Corynebacteriae-! Diverse group of commensals in your tracheal and oral mucosa and pathogens.! Infect many animal species.! |
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What is the big animal corynebacterium?
What are the two major biotypes? |
Corynebacterium pseudotuberculosis
• Two biotypes: _nitrate__ reducers and non- _nitrate_ reducers. |
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What are the two corynebacterium biotypes?
What is the difference in their infections? |
Two biotypes: __nitrate_ reducers and non-
_nitrate_ reducers.! •! Reducers: infect horses and cattle! !Ulcerative lymphangitis! •! Non-reducers: sheep and goats! _caseous__ lymphadenitis! Worldwide, endemic in areas with lots of sheep and goats.! |
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What is the mechanism of action of ulcerative lymphangitis?
How does the disease come on? How do you treat it? How is the dz introduced? |
Corynebacterium
Ascends __lymphatics__, leaving a track of ulcers.! Seasonal- arthropod vector suspected Skin wounds, ! arthropod bites,! Contaminated hardware! Onset of disease is __slow_. Infects the lymphatics (lymph vessels).! These swell and form nodules, these ulcerate and exude pus.! Systemic antibiotics, wash with _antiseptic shampoo_.! |
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What species does casesous lymphadenitis effect?
How is it transmitted? What type of bacteria is this? How is this treated |
Corynebacterium
Treatment is through antiseptic use - very hard to get rid of though Serious disease of sheep and goats •Contact with infected animals and via _environment_. Pathogen can survive in the environment for over 6 months. •Also can be transferred via contaminated_shears_, through insect bites, contaminated dips. •Infection of the lymph nodes |
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How do you control caseous lymphadenitis?
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Corynebacterium
Control: import restrictions, _quarantine_, possible vaccination. ! If endemic, tough to get rid of. Antibiotics don’t get into lesions…! |
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What are the C. pseudotuberculosis vir. factors?
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Corynebacterium
Cell wall lipids- allow survival in host, antiphagocytic, protection against H 2O2, etc. ! Secreted___phospholipase D__- active against mammalian cell membranes.! Note: Corynebacteria in this group can produce _diphtheria toxin__ and perhaps infect people through raw milk.! |
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What is the pathogenesis of C. pseudotuberculosis?
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Corynebacterium
• Pathogen enters through break in skin or -less common- inhalation or ingestion. • Microscopic abscesses form at the site. • Phagocytosis- organisms remain viable within phagocytes. • Pathogen “hitchhikes” with phagocyte and is disseminated. • Phagocyte is lysed, likely from action of phospholipase D and perhaps cell wall components • Abscesses begin to form at these secondary sites- can be very large. • Pathogen may also disseminate from secondary sites of infection. • phospholipase D a critical virulence factor-deleted strains do not cause disease in model systems. • Antibodies to PLD are protective (how antibodies to an intercellular antigen is complicated - there is likely something else going on, an intermediate step) - – Vaccine consisting of inactivated whole cells plus culture sup is available and works in sheep, not goats. • Case-Bac Other vaccines are being experimented with Toxin deleted strains, DNA vaccines - if you can vaccinate, you can control the enzyme and neutralize the infectious process. |
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What are the other corynebacterium that cause ascending infections in the urinary tract?
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These are normal urinary tract bacteria that cause problems up north
•! C. renale, pilosum, cystidis! –! Bovine cystitis! –! Normal flora of repro. tract of cattle.! –! C. renale most common, pilosum least pathogenic.! –! All possess adhesive pili! –! Ascending infections- end up in kidney and bladder.! |
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What causes pizzle rot?
What enzyme is this corynebacterium positive for? |
C. renale-!
_urease_ positive- breaks down urea to ammonia plus CO 2! C. renale is associated with Ovine Posthitis: ”Pizzle Rot”! Commensal of the urinary tract- also on dermis outside UT/GT.! Urea breakdown leads to ammonia- based tissue destruction/scarring! Functional problems in urination/ insemination. ! |
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Which corynebacterium is an uncommon cause of mastitis?
Which leads to a very serious human infection? |
•! C. ulcerans- uncommon cause of _urease__.!
•! C. diphtheriae- very serious human infection! –! Bacteriophage encoded ________- leads to potentially fatal human disease.! –! Most of us are vaccinated against C. d.- DPT and DT vaccines.! •! C. ulcerans can cause human disease.! –! Raw milk, milk by products.! |
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What is the important virulence factor of arcanobacgterium pyogenes ?
What does this bacteria typically follow? |
It is histolytic (tissue degrading) enzymes
Disease often follows __traumatic injury__! •! Common opportunist in ruminants and pigs! •! Dissemination following injury, leads to abortion, suppurative infections! •! Common in mixed infections! Present in up to 90% of liver abscesses !! Ruminal acidosis- leads to infections.! |
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What kinds of animals does A. pyogenes cause mastitis in?
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(Arcanobactera pyogenes)
Dry animals, or lactating animals suffering an injury to the teat. – Thick purulent secretions Can also be involved in uterine infections Common inhabitant of mucosal surfaces. Introduced to submucosal sites by trauma/insult/poor hygiene. Vaccination challenging- no real success in this area. Work with cytolysin vaccine has potential. pyolysin- chol. Dep. cytotoxin |
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What arcanobacterium is associated with ruminal acidosis?
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Associated with high grain feeding!
•! Leads to lesions on wall of rumen- bacteria escape.! •! Primary pathogen is _fusobacteirum_! |
