Flashcards in E2 Anaerobes Deck (47)
Where do anaerobes like to live?
What is common pathogenic factor among anaerobes?
What are the two classes of anaerobes?
1. Obligate = die in O2
2. Aerotolerant = kinda like facultative bacteria but use fermentation
Why do obligate anaerobes die when exposed to O2?
H202 and superoxide are formed
= lack enzymes to deal with these chemicals
What are signs of an anaerobic infection (4)?
1. Painful tissue necrosis
2. Gas in the wound
3. Foul odor
4. Black discoloration
What are some anaerobic environments in healthy animals?
1. Oral cavity between teeth and gums
How can anaerobic grow in wounds?
Facultative bacteria use up all the O2 first
What is Eh?
Measure of redox potential
Lower Eh = more anaerobic environment
What is a spore forming Gram POSITIVE bacteria that are anaerobic?
What are the two groups of Clostridium?
1. Tissue invasive w/ weak toxins
2. Non-invasive w/ severe toxins
Where do Clostridium live in nature?
Can also be normal commensals
What is type A Clostridium?
Has only alpha toxin
Normally present in intestines of healthy animals
What type of toxins do Clostridia have?
= secreted toxins
What is the most dangerous toxin?
What type of diseases are caused by Type A Clostridium?
Necrotizing myositis in horses
Yellow lamb disease = enterotoxemia
What toxin is in Type D clostridium?
Alpha & Epsilon toxins
What are some disease caused by Type D clostridium?
Enterotoxemia of sheep & goats
"Pulpy kidney disease"
= Epsilon toxin!
What is Clostridium chauvoei?
Black leg in ruminants
3. Tooth loss
= necrotic muscle tissue
What is special about Clostridium chauvoei's pathogenesis?
Can remain latent until tissue is damaged!
What is Clostridium septicum?
Ingestion of spores
Rapid death! 1-2 hrs
How is Clostridium septicum different from Clostridium chauvoei (Blackleg)?
C. septicum does NOT produce gas!
What is Clostridium difficile?
What can cause Clostridium difficile infections?
What are the clinical signs of Clostridium difficile infection?
How is Clostridium difficile diagnosed?
PCR of feces
What are the 2 non-invasive super toxic Clostridia?
1. C. botulinum
2. C. tetani
What is Clostridium tetani?
Causes Tetanus or "Lockjaw"
What species are most susceptible to Clostridium tetani? Least susceptible?
Most = Horses & Humans
Least = Cats, Chickens
Of the 3 Clostridium tetani toxins which one is the most pathogenic? What does it do?
Blocks inhibitory NTs at NMJs