Anaerobes - part 2 Flashcards
What are the virulence factors of Clostridium perfringens
Exotoxins
Enterotoxin
Degradative enzymes
What are the main/most important C. perfringens exotoxins?
Phospholipase C and alpha toxin - disrupt mammalian cell membranes
The enterotoxin of C. perfringens is heat labile but….
the spores remain viable for >1 hour at 100°C
What are the important temperatures to keep food at?
60°C + for hot food
4°C and below for cold food
C. prefringens is always associated with what kind of gangrene?
gas producing gangrene
Why is C. prefringens named as such?
when you colonize it, have inner and outer edges on agar
What is the most feared complication of wound infection?
Gas gangrene (C. perfringens)
Rapidly advancing inflammation, very painful, usually originating at a site of tissue devitalization.
gas gangrene
Late in the course, ___ _______ can be felt in 80% of cases of gas gangrene.
gas crepitation
What is the treatment for gas gangrene?
Radical surgery plus penicillin
Sporulating gram positive anaerobic rod with two exotoxins and widespread in the environment.
Clostridium difficile
Clostridium difficile is a common floral agent where?
Enteric flora
C. diff is common in what individuals?
infants < 8 months
Healthy adult carrier rates of C. diff are about 2-5%, how does this number go up?
Recent antibiotic use and hospitalization
Most common cause of infectious diarrhea in hospitals and long-term care facilities.
C. diff
Infection associated with antibiotic use
C. diff
What are some of the most severe symptoms/signs of C. diff infection?
Severe colitis, toxic megacolon, perforation, sepsis (i.e. progression to the latter from the former)
Most cases of C. diff diarrhea are _____.
Mild - do not require investigation or treatment
There is a _________ strain of C. diff.
hypervirulent
Major anaerobes of the colon
Bacteroides fragilis
Describe the morphology and staining of Bacteroides fragilis
Gram negative rods
What does Bacteroides fragilis cause?
Peritonitis and abdominal abscesses
What does Bacteroides fragilis produce in terms of protection?
B-lactamase - not susceptible to penicillin type antibiotics
Propionibaterium elaborates what?
Propionic acid
