Anaerobic infections: Bench to Bedside

Question 1

What are the two classes of anaerobic organisms?

Answer 1

gram positive and gram negative

Question 2

What are some main anaerobic gram positive organisms?

Answer 2

Gram positive – Clostridium, Peptosptreptococcus, Actinomyces

Question 3

What are some main anaerobic gram negative organisms?

Answer 3

Gram negative – Bacteroides, Prevotella, Porphyromonas, Fusobacterium

Question 4

What is the pathogenesis of infections with anaerobes?

Answer 4

a. Endogenous anaerobes (normal flora) gain access to normally sterile sites
b. Contamination of wound or puncture by objects contaminated by anaerobes
c. Ingestion of preformed toxins present in food
d. Depopulation of normal GI flora allowing anaerobes to multiple
e. Nosocomial

Question 5

What type of bacilli is Clostridium?

Answer 5

• Gram positive or Gram-variable bacilli, spore-forming
• Clostridium species associated with human infections
  o Clostridium tetani
  o Clostridium perfringens
  o Clostridium botulinum
  o Clostridium difficile

Question 6

What is the source of clostridium tetani? What are the infection results in tetanus and what prevention of infections and treatment of infection is used/

Answer 6

Clostridium tetani
- source: soil / environment
- infection results in tetanus
- prolonged contraction of skeletal muscles, drooling, excessive sweating,
fever, swallowing difficulty/breathing difficulty, uncontrolled urination/defecation
- prevention of infection – immunization
- treatment of infection
- Tetanus immune globulin
- systemic antibiotics against clostridium
- supportive care – ventilator, IV fluids/NPO, etc

Question 7

What is the source of clostridium perfringens? What does the infection usually result in? and the treatment?

Answer 7

Clostridium perfringens

• source: environment, GI tract
• infection results in:
• watery diarrhea and abdominal cramping - toxin induced
• self-limited, rehydration, no abx
  
  • gas gangrene: toxin mediated destruction of tissues
    
    • surgical debridement, abx

Question 8

What is the source of clostridium botulinum? What is the infection that usually results? What treatment should be applied?

Answer 8

Clostridium botulinum

• source: soil / environment
• infection results in botulism due to release of toxin that prevents release of acetylcholine at cholinergic nerve junctions
  
  • ingestion of contaminated foods: descending symmetric paralysis, dry mouth and throat (decreased production of saliva), postural hypotension, constipation (decreased peristalsis)
  • infant botulism
  • infected wound site: wound botulism
• treatment – supportive care: ventilation, IV fluids
  
  • botulism immune globulin
  • botulinum antitoxin

Question 9

For clostridium difficile, what is the source, type of ifection, and complications, as well as treatment?

Answer 9

Clostridium difficile

• source: GI tract, nosocomial spread from contaminated environment
• infection results in colitis: abdominal cramping, watery diarrhea
• complications: toxic megacolon, perforation, shock
• treatment – abx