8. GI Pathogens 2 (Steph) Flashcards
4 major characteristics of clostridia
- gram positive
- anaerobic
- spore forming
- produce exotoxins
C. perfringens 5 toxinotypes
A,B,C,D,E
C. perfringens 4 major toxins
alpha, beta, epsilon, iota
common disease of C. perfringens toxinotype A
myonecrosis, fowl necrotic enteritis, bovine and ovine enterocolitis, porcine necrotic entercolitis
common disease of C. perfringens toxinotype B
ovine hemorrhagic enterotoxemia, hemorrhagic enteritis
common disease of C. perfringens toxinotype C
neonatal hemorrhagic or necrotizing enterotoxemia (ovine, porcine, bovine, equine)
common disease of C. perfringens toxinotype D
ovine enterotoxemia
common disease of C. perfringens toxinotype E
bovine hemorrhagic enteritis
what does C. perfringens alpha toxin act on
Phospholipase: acts on membranes; cytolytic, hemolytic, dermonecrotic
what does C. perfringens beta toxin act on
pore forming activity, HEMORRHAGIC, cytolytic, dermonecrotic
what does C perfringens epsilon toxin act on
alerations of cell membrane permeability –> edema in various organs (liver, kidney, CNS)
what does C. perfringens iota toxin act on
Hemolysin: pore forming, cytotoxic, lethal leakage of water and ions by enterocytes and diarrhea
Describe the zoonotic component of C.perfringens type A
some strains of C.perfringens type A produce an enterotoxin (CPE) at the moment of sporulation causing disease in humans
describe how CPE causes food poisoning in humasn
- pore formation: cytotoxic due to plasma membrane permeability alterations
- interactions with epithelial tight junctions –> alter paracellular permeability
Type A C.Perfringens in poultry
Necrotic enteritis, necrosis in jejunal and ileal mucosa, sometimes mild NE results in decreased rates of gain, short clinical course culminating in dealth
what predisposes poultry to Type A C.perfringens
high fiber diet and concurrent coccidiosis
Type A C.perfringens in sucking and feeder pigs
necrotizing enterocolitis with mild villous atrophy. jejunal and ileal lesions are heavily colonized with C. perfringens
Type A C.perfringens in equine:
neonatal hemorrhagic diarrhea. clinical pres: watery-mucoid diarrhea to peracute death with hemorrhagic mucosal necrosis
Type A C.perfringens in beef calves
abomasal ulceration and tympany
Type A C.perfringens in dairy calves
necrotic enteritis in newborn calves
Type A C.perfringens in adult cattle
haemorrhagic bowl syndrome
what is “red gut”? what is it caused by
post mortem finding in enterotoxemic and sudden death dairy and feedlot cattle. large segments of small intestine arereddish purple and filled with blood. large numbers of C.perfringens can be isolated from jejunum
C. perfringens lesions
necro-haemorrhagic enteritis: severe dilated and congested small intestine
C. perfringens histological lesions
sloughing in large intestine, lots of immune cells and cell death