clostridia Flashcards
clostridium perfringens
large rod shaped, nonmotile, encapsulated, double zone of hemolysis, anaerobic cellulitis
- food poisoning
clostridium
gram-positive rods, anaerobic, extracellular, spore former
type of clostridium perfringens that is responsible for most human infections
type A
alpha toxin is also known as
lecithinase
what does alpha toxin (lecithinase) do?
degrades lecithin in mammalian cell membranes
exotoxins effects
hemolytic or other cytotoxic and necrotic effects either locally or when dispersed in the bloodstream
myonecrosis (gas gangrene)
painful, rapid destruction of muscle tissue; systemic spread with high mortality
clostridial endometritis
gangrenous infection of uterine tissue is followed by toxemia and bacteremia
is clostridial myonecrosis fatal
uniformly within days of initiation if left untreated
treatment for clostridial myonecrosis
antibiotics and hyperbaric oxygen
clostridium perfringens enterotoxin
heat liable and can be detected in contaminated food and feces
clostridium botulinum causes
botulism- fatal food poisoning in people and animals
source of clostridium botulinum
soil borne organism can also be found in GI tract of mammals
transmission of clostridium botulinum
ingestion of pre-formed toxin (different from tetanus)
risk factors of clostridium botulinum
immature GI flora (infants and foals)
mechanism of action of Botulinum toxin
toxin survives in stomach acid, absorbed into the bloodstream, inhibits release of Ach, results in paralysis
classic botulism
food poisoning
clinical signs of botulism
difficulties in vision, swallowing, and other cranial nerve functions…a progressive paralysis of muscles, starting in the head and neck region and moves down the body to the arms, legs, and chest (mortality happens due to respiratory paralysis)
most common form of botulism in the US
infant botulism- transmitted by honey contaminated with C botulinum
clostridium tetani
source: soil-borne organism, transmission: spores are inoculated into wounds
risk factors: recent wound (puncture wound)
management practices: ear tags, castration, tail docking
tetanus presents as_____
spastic paralysis, in which muscle spasms often first involve the site of infection
lockjaw is indicative of
tetanus
clostridium difficile
gram-positive, spore-forming rod, strict anaerobe
- spores can be detected in hospital rooms of infected patients (exogenous source of infection)
clinical significance of clostridium difficile
antimicrobial drugs have been reported as predisposing to clostridial AAD and colitis
pseudomembranous colitis
most severe form: profuse diarrhea, abdominal cramping, and fever
- white plaques
