20 Enteric Clostridium Flashcards
Organisms from the genus Clostridium are generally ________ (aerobic/anaerobic), shaped like ______ (rods/cocci), and are Gram _____ (+/-).
Anaerobic
Rods
G+
Although most Clostridium are Gram ___ (+/-), an exception is ______ (specific bacterium).
G+
C. piliforme (Tyzzer disease)
T or F: clostridium can form environmentally resistant spores.
T
Describe enterotoxemia.
Toxins are produced within the gut, enter the bloodstream, and then act on distant organs.
What are the six major types of toxins (not toxinotype) that C. perfringens can be encoded for based on the 2018 toxin-based typing scheme?
Alpha-toxin
Beta-toxin
Epsilon-toxin
Iota-toxin
CPE (enterotoxin)
NetB
What are the 7 toxinotypes of C. perfringens based on the 2018 toxin-based typing scheme?
A
B
C
D
E
F
G
T or F: it is rare to find C. perfringens in the intestine of a healthy animal.
F
C. perfringens toxinotype A is encoded for which toxin(s)?
Alpha-toxin
What specific organism causes Yellow Lamb Disease?
C. perfringens type A
What is the pathogenesis of yellow lamb disease?
Alpha-toxin causes intravascular hemolysis, which results in anemia and free hemoglobin. The anemia leads to hypoxic injury and hepatic necrosis. The free hemoglobin causes a nephropathy and icterus.
How is yellow lamb disease diagnosed?
Clinical signs and gross/histo appearance are suggestive. Culture with typing and a colony count over 10^6 CFU are confirmatory.
C. perfringens type B are encoded for which toxin(s)?
Alpha toxin
Beta toxin
Epsilon toxin
Lamb dysentery is caused by _______ (specific bacteria).
C. perfringens type B
T or F: lamb dysentery is prevalent in the Americas.
False – not diagnosed in the Americas
C. perfringens type C is encoded for which toxin(s)?
Alpha toxin
Beta toxin
+/- CPE
What is the general effect of C. perfringens type C?
Necrotizing
What is clostridial Beta-toxin sensitive to?
Trypsin
Briefly explain the relationship between clostridium and trypsin.
Clostridium inactivates trypsin, because otherwise trypsin would destroy all of the antibodies in the colostrum.
Trypsin deficiency or inhibition can lead to what kind of infection?
C. perfringens type C
What food items can cause trypsin inhibition if they are consumed in large quantities?
Sweet potatoes and soybeans
What age does C. perfringens type C most commonly affect, and why?
Neonates due to colostrum inactivating trypsin
What disease does C. perfringens type C cause in humans?
Enteritis necroticans
What are the clinical signs of C. perfringens type C?
Hemorrhagic diarrhea
Neurologic signs
Sudden death
What animal species are most likely to be clinically affected by C. perfringens type C enterotoxemia?
Neonatal livestock and horses
How is enterotoxemia from C. perfringens type C diagnosed?
Clinical signs, gross/histo, and culture with typing are suggestive. Fecal/intestinal content testing for Beta toxin is confirmatory.
C. perfringens type D is encoded for which toxin(s)?
Alpha toxin
Epsilon toxin
+/- CPE
What is the MOA of Epsilon toxin?
Increases vascular permeability
What is required for epsilon toxin to become activated?
Trypsin
What are the clinical signs of disease caused by C. perfringens type D?
Neurologic signs
Respiratory difficulty
Sudden death
(Usually no diarrhea)
What can cause excessive overgrowth of C. perfringens type D in ruminants?
Excessive carbohydrate ingestion
How is disease from C. perfringens type D diagnosed?
Clinical signs, gross appearance, and culture with typing are suggestive. Histology and testing of intestinal contents or feces for Epsilon toxin are confirmatory.
C. perfringens type E produces which types of toxin(s)?
Alpha toxin
Iota toxin
+/- CPE
What species has C. perfringens type E enterotoxemia been observed in?
Cattle, rabbits, sheep
C. perfringens type F produces which type of toxin(s)?
Alpha toxin
CPE
What type of enterotoxin is a cause of human food poisoning?
CPE
C. perfringens type G is encoded for which type of toxin(s)?
Alpha toxin
NetB
What causes necrotic enteritis in poultry?
C. perfringens type G
What is a major predisposing factor for C. perfringens type G enterotoxemia in poultry?
Eimeria co-infection
What is the most virulent factor of C. perfringens type G?
NetB
What are the clinical signs of C. perfringens type G in poultry?
Loss of production
Depression
Diarrhea
Sudden death
How is enterotoxemia from C. perfringens type G diagnosed?
Clinical signs, gross/histo, and culture with typing are individually suggestive, and all three combined may be confirmatory.
What is the main cause of antibiotic associated diarrhea in humans and animals?
C. difficile
What are the main virulence factors of C. difficile?
Toxin A
Toxin B
CDT
What are the clinical signs of C. difficile infection in HORSES?
Diarrhea (+/- hemorrhage) and colic in all age groups
What histologic lesion is characteristic for C. difficile?
Volcano lesions–lymphocytes bursting up through intestinal epithelium
What are the clinical signs of C. difficile infection in PIGS?
Diarrhea (+/- hemorrhage), constipation, colic
How is C. difficile infection diagnosed?
Clinical signs, gross/histo, and culture + typing are suggestive. Ancillary A/B toxin testing is confirmatory.
What is the causative agent of Tyzzer disease?
C. piliforme
What species are affected by Tyzzer disease?
Horses, rabbits, rats, hamsters, cats, other
What is the triad of lesions associated with Tyzzer disease?
Hepatitis
Colitis
Myocarditis
What is a characteristic gross lesion caused by C. difficile in the intestines?
Mesocolonic edema
How is Tyzzer disease diagnosed?
Histology (+ special stains), PCR, culture
How is Paeniclodtridium sordellii diagnosed?
Rule out other causes of enteric disease and prove presence of P. sordellii on culture, PCR, or IHC
What is the causative agent of quail disease?
C. colinum
What gross lesions do C. colinum cause?
Transmural ulceration of the pancreas and duodenum
What is the causative agent of rabbit enterotoxemia?
C. spiroforme
