Microbiology · Gram-positive rods
Clostridium perfringens !
- Bacterium
- Gram-positive
- Exam priority: medium
A bacterium that causes gas gangrene in deep wounds and a common food poisoning from reheated meat and gravy.
Updated 2026-11-01
Also called: gas gangrene bacillus
At a glance
- Gram
- Gram-positive
- Shape
- Thick rod; spores rarely seen
- Oxygen
- Anaerobe (aerotolerant)
- Family
- Clostridiaceae
- Stain
- Gram positive; spore former
Morphology
- Thick, boxcar-shaped Gram-positive rod
- Double zone of haemolysis on blood agar
- Non-motile
Transmission
- Deep wounds contaminated with soil (trauma, war, surgery)
- Food cooked in large batches and kept warm (meat, poultry, gravy)
Isolation precautions
What the care team adds to standard precautions.
- Standard
Virulence factors
- Alpha toxin (lecithinase, phospholipase C): destroys membranes, causes myonecrosis and haemolysis
- Enterotoxin: diarrhoea in food poisoning
- Gas production in tissue
Diseases it causes
- Gas gangrene (clostridial myonecrosis)
- Food poisoning with watery diarrhoea and cramps Acute (viral) gastroenteritis →
Clinical picture
- Severe pain in a wound, swelling, bronze to purple skin and crepitus
- Rapid progression to shock
- Diarrhoea and cramps without much fever, settling on their own
Diagnosis
- Clinical and surgical diagnosis in gangrene
- Tissue Gram stain: large Gram-positive rods with few neutrophils
- Gas in tissue on X-ray
- Nagler reaction (lecithinase) in the lab
Treatment
Gas gangrene is a surgical emergency: wide debridement or amputation, plus penicillin and clindamycin; some centres use hyperbaric oxygen. Food poisoning only needs rehydration.
Drug class only; doses and regimens are set by the clinician from the current guideline.
In Pharmacology:
Prevention
- Prompt cleaning and debridement of wounds
- Chill cooked food quickly and reheat it thoroughly
Test yourself
Think of the answer, then tap the question to see it.
Which C. perfringens toxin causes gas gangrene?
Alpha toxin, a lecithinase (phospholipase C) that destroys cell membranes.
Which physical sign suggests gas in tissue?
Crepitus when the area is palpated.
Which foods are linked to C. perfringens food poisoning?
Meat, poultry and gravy cooked in large batches and kept warm.
Related
Related conditions
← Back to the group: Gram-positive rods
Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: About C. perfringens food poisoning (CDC, 2024); Gas gangrene: MedlinePlus Medical Encyclopedia (MedlinePlus (NLM), 2024).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.