Which organism is an important cause of food poisoning?

• A. Bacteroides fragilis
• B. Bacteroides ureolyticus
• C. Clostridium perfringens
• D. Clostridium histolyticum

Answer: (C)

Foodborne illness from bacteria often comes from toxins produced in food or after the organism is ingested. Clostridium perfringens is a classic cause of food poisoning because its spores can survive cooking; if cooked meat or poultry is kept at improper temperatures, the spores germinate and the bacteria produce an enterotoxin in the small intestine. Ingesting a large number of organisms leads to abdominal cramps and watery diarrhea within about 6–24 hours, with vomiting being less common. This pattern—meat-associated, rapid onset, with cramping and diarrhea—points to Clostridium perfringens as the responsible organism.

The other organisms listed are not typical food poisoning culprits. Bacteroides species are part of the normal gut flora and more often cause intra-abdominal infections or abscesses in anaerobic settings, not classic foodborne intoxications. Clostridium histolyticum is noted for producing collagenases and causing tissue damage, not for foodborne illness.