Properties

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment & Prevention

Gram-positive rods

Obligate anaerobes

Form spores

Gas gangrene:

- spores are located in the soil.

- vegetative cells are members of normal flora of colon & vagina.

- found in human species.

- associated with war wounds, automobile & motorcycle accidents, septic abortions.

- produce alpha toxin (lecithinase) which destroys cell membrane and kills cells.

- other species: C.novyi & C.septicum

Food poisoning:

- spores located in soil & on food.

- heat-resistant spores survive cooking, germinate & grow in reheated foods.

Gas gangrene:

- pain, edema & cellulitis occur in wound area. discoloration of skin.

- hemolysis & jaundice.

- shock & death can ensure, with high mortality rate.

- crepitation – presence of gas in tissues.

- thin smelly discharge.

Food poisoning:

- abdominal cramps.

- diarrhea.

Neutropenic enterocolitis:

- spores enter tissues via bloodstream.

- there may be underlying disease of bowel, leukemia or diabetes.

- gas gangrene develops in absence of penetrating injury.

- organism is usually C.septicum.

Smears of tissue and exudate samples show large gram-positive rods.

Organism cultured anaerobically & identified by sugar fermentation reactions.

Serologic tests are not useful.

Gas gangrene:

- benzylpenicillin + metronidazole + gentamicin.

- early surgery to remove all dead or damaged tissue.

- hyperbaric oxygen reduce spread of infection.

Food poisoning:

- rehydration

- antibiotics not indicated

Prevention:

- good surgical technique.

- avoid damaging tissues.

- careful debridement of traumatized tissue.

- remove all dead or unhealthy tissue.

- food adequately cooked to kill organism.