Enteropathogenic Clostridia Flashcards
What species of Clostridium are enteropathogenic and enterotoxemia producing?
C. perfringens, C. difficile, C. colinum, C. spiroforme, C. piliforme
What are some general characteristics of C. perfringens?
gram positive pleomorphic rods, obligate anaerobes, non-motile, spores of boxcar shaped appearance
What is unique about the structure of C. perfringens?
only clostridium that possesses a capsule
What is the habitat of C. perfringens?
soil, feces, GI tract - invades dead tissue post-mortem
What type of C. perfringens is part of the normal intestinal flora and causes both enterotoxigenic/enteropathogenic and histotoxic infections?
type A
What are some predisposing factors of C. perfringens?
inappropriate husbandry, sudden dietary changes, environmental influences
What are the four major toxins of C. perfringens?
alpha toxin (all strains), beta toxin (B and C strains), epsilon toxin (B and D strains), iota toxin (E strain)
What does alpha toxin of C. perfringens cause?
hemolysis and cell necrosis
What does the beta toxin of C. perfringens cause?
enteritis and contraction of intestinal smooth muscle
What are the epsilon and iota toxins of C. perfringens produced as?
pro-toxins
What are some other virulence factors of C. perfringens?
8 other exotoxins, minor toxins/enzymes, capsule
What is the causative agent of necrotic enteritis (rot gut) in chickens?
C. perfringens type A
How is necrotic enteritis (rot gut) transmitted?
fecal-oral route
What are some predisposing factors of necrotic enteritis (rot gut)?
dietary, mucosal damage, coccidia occurring concurrently
What are some clinical signs of necrotic enteritis (rot gut)?
sudden death, depression, ruffled feathers, diarrhea
How do you diagnose necrotic enteritis (rot gut)?
clinical signs and post-mortem findings, smear and gram-stain of intestinal mucosa, histological findings, isolation of C. perfringens from intestinal contents
How do you treat and control necrotic enteritis (rot gut)?
antibiotics in water, prevent coccidiosis, good diet, isolation of sick animals
What is the causative agent of lamb dysentery?
C. perfringens type B
What are some clinical signs of lamb dysentery?
sudden death with no premonitory signs, abdominal distension, pain, bloody feces
What are some predisposing factors of lamb dysentery?
low proteolytic activity in neonatal intestines, incomplete establishment of normal intestinal flora in neonates, dietary influences in older animals
How do you diagnose lamb dysentery?
clinical signs and post-mortem findings, demonstration of gram-positive rods from intestinal mucosa, anaerobic culture to isolate C. perfringens, ELISA
What are some post-mortem findings of lamb dysentery?
hemorrhagic enteritis with ulceration of small intestine, fluid accumulation in peritoneal cavity and pericardial sac NOTE: no visible external lesions
What is the causative agent of “struck” in sheep?
C. perfringens type C
What is the major toxin of “struck” in sheep?
beta toxin NOTE: causes intestinal inflammation and necrosis
What is the minor toxin of “struck” in sheep?
alpha toxin NOTE: causes hemolysis
What are some clinical signs of “struck” in sheep?
sudden death, acute enterotoxemia in adult sheep, possible terminal convulsions
What are some post-mortem findings of “struck” in sheep?
jejunal ulceration, patchy hyperemia in small intestines, peritonitis
What is the causative agent of hemorrhagic enteritis in pigs?
C. perfringens type C
What is the pathogenesis of hemorrhagic enteritis in pigs?
beta toxin -> binds vascular endothelial cells -> vascular necrosis and necrosis of villi
What are some clinical signs of hemorrhagic enteritis in pigs?
sudden death in newborn piglets, dullness, anorexia, blood-stained feces, perianal hyperemia
What are some post-mortem findings of hemorrhagic enteritis in pigs?
hallmark lesion, necrosis of intestinal mucosa with blood stained contents in small intestines, cecum, and colon, serosanguineous fluid in the pleural and peritoneal cavity
What is the hallmark lesion of hemorrhagic enteritis in pigs?
segmental mucosal necrosis with marked hemorrhage in the small intestine
What is the causative agent of pulpy kidney (over-eating disease)?
C. perfringens type D
What species are mostly affected by pulpy kidney (over-eating disease)?
thriving lambs 3-10 weeks old
What is the predisposition of pulpy kidney (over-eating disease)?
excessive consumption of high grain and low roughage diet, immunocompromised animals, GI parasites, decreased intestinal motility
What is the pathogenesis of pulpy kidney (over-eating disease)?
high starch content -> rapid proliferation of clostridial organisms -> partially digested food from rumen to intestine -> production of epsilon (major) toxin and beta (minor) toxin
What are some of the clinical signs of pulpy kidney (over-eating disease)?
lambs found dead, dullness, opisthotonos, convulsions, coma, blindness, head pressing, bloating in later stages, hyperglycemia and glycosuria