Anaerobic Organisms Flashcards
An aerobic bacterial wound culture was reported. What organisms can you not rule out?
Clostridium
Organisms that can produce spores include:
A) Bacillus (aerobic) and bacteroides (anaerobic)
B) Bacillus (anaerobic) and Bacteroides (Aerobic)
C)Bacillus (aerobic) and Clostridium (anaerobic)
D) Bacilus (anaerobic) and clostridium (aerobic)
C
An organism causing pseudomembranous colitis after prolonged antibiotic use is most consistent with:
Clostridium difficle
Infections caused by which anaerobic organisms are confirmed via culture?
Bacteroides fragilis and Clostridium perfringens
The Gram stain reaction and morphology of the most common anaerobic organism isolated in the clinical laboratory is:
gram-negative bacilli- Bacteroides fragilis
An organism causing gas gangrene in which wound direct specimen Gram stains will often lack white blood cells due to cell lysis is:
Clostridium perfringenes
Organism leading to Flaccid paralysis leads to Resp paralysis (death); Wounds (rare)
Clostridium botulinum
Gram stain of Clostridium sp.
Gram positive bacilli- most produce spores when stressed
What is widely distributed in soil and water and associated with home canning and honey?
Clostridium botulinum
Virulence factor of Clostridium botulinum
Neurotoxin- inactivates proteins that regulate release of Ach
How is Clostridium botulinum identified in the lab
Confirmed via toxin detection Usually performed by public health lab
Most frequently isolated clostridium sp.
perfringens
Virulence factor of Clostridium perfringens
Alpha toxin: lyses RBCs, [;ate;ets, WBCs, tissue; hepatic toxicity; myocardial dysfunction
Eating what type of food can put you at risk of getting Clostridium perfringens enterotoxin. How would you treat?
Meat products: beef, chicken, turkey. No treatment necessary.
Clostridium perfringens reatment
Debridement, excision or amputation of dead tissue. Antibiotic therapy: penicillin (high dose) plus clindamycin.
-Hyperbaric oxygen- effectiveness inconclusive.
What anaerobic organism is normal flora of mouth, Upper respiratory tract, GI tract, and urogenital tract that can cause infect wounds, abscesses, bacteremia, other infections?
Bacteroides fragilis group
How is clostridum butulinum confirmed?
Via toxin detection- usually performed in public health lab
How is clostridium perfringens confirmed?
Via anaerobic culture. Gas gangrene culture shows necrotic tissue with large rectangular rods with lack of inflammatory cells.
How is clostridium tetani confirmed? Treatment?
Via clinical symptoms. Debridement, Metro, Antitoxin.
How is clostridium difficile confirmed? Treatment?
Via toxin in stool (Metro and vanco)
How is Bacteroides fragillis confirmed? How would you treat?
Via anaerobic culture- treat with beta lactam and beta lactamase inhibitor (Metronidazole and Imipenem)
How do anaerobes obtain energy?
Fermentation
T/F: Strict obligate anaerobes can cause human infections.
False: Not associated with humans. Cant be cultured because oxygen is toxic. Moderate obligate anaerobes cause human infections.