Which organism produces alpha-toxin (lecithinase) and is associated with gas gangrene and food poisoning?

• A. Listeria monocytogenes
• B. Clostridium difficile
• C. Clostridium perfringens
• D. Bacillus cereus

Answer: (C)

Alpha-toxin (lecithinase) is a phospholipase that Clostridium perfringens makes to attack cell membranes. By cleaving phospholipids, it damages tissues and blood vessels, leading to rapid cell death, tissue necrosis, and gas production in infected wounds—hallmarks of gas gangrene. In addition, large numbers of C. perfringens can cause food poisoning when they contaminate foods; the bacteria produce an enterotoxin during sporulation in the gut, producing short-lived diarrhea and abdominal cramps. This combination of a membrane-damaging toxin and the classic association with both gas gangrene and food poisoning points to Clostridium perfringens as the responsible organism. Other organisms listed do not produce this toxin and have different disease profiles (for example, Listeria causes meningitis and sepsis, C. difficile causes pseudomembranous colitis, and Bacillus cereus causes its own distinct foodborne illness).