A 32-year-old woman from rural Maharashtra presents to the emergency department with sudden onset of severe abdominal pain, profuse watery diarrhea, and vomiting for 6 hours. She had consumed leftover chicken curry kept at room temperature for 2 days. On examination, she is afebrile (37.2°C), blood pressure 100/65 mmHg, with mild dehydration. Stool examination shows no blood, WBC, or RBC. Blood culture is negative. Which toxin is most likely responsible for her clinical presentation?

Explanation

## Clinical Diagnosis: Clostridium perfringens Food Poisoning **Key Point:** This is a classic presentation of C. perfringens food poisoning, characterized by acute onset (6–24 hours post-ingestion) of crampy abdominal pain and watery diarrhea WITHOUT fever or bloody stools. ### Pathophysiology C. perfringens produces **enterotoxin (CPE)** during sporulation in the small intestine. The toxin: - Binds to claudin and occludin on intestinal epithelial tight junctions - Causes loss of intestinal barrier integrity - Leads to watery diarrhea and abdominal cramping - Does NOT cause systemic toxemia (hence afebrile, negative blood culture) ### Clinical Features of C. perfringens Food Poisoning | Feature | Present | Absent | | --- | --- | --- | | Onset | 6–24 hours | Fever | | Diarrhea | Watery, profuse | Blood/mucus | | Abdominal pain | Crampy, severe | Vomiting (mild) | | Blood culture | Negative | — | | Duration | 24–48 hours | — | **High-Yield:** C. perfringens is the **second most common bacterial cause of food poisoning** in developed countries (after Salmonella). In India, it ranks among the top 5 foodborne pathogens. ### Why Enterotoxin (CPE) is the Answer 1. Produced during **sporulation** in vivo (not preformed in food) 2. Acts locally on intestinal epithelium → watery diarrhea 3. No systemic invasion → afebrile, negative blood culture 4. Incubation period 6–24 hours matches the timeline **Clinical Pearl:** Unlike Staphylococcal food poisoning (preformed toxin, vomiting-predominant, 1–6 hours), C. perfringens causes diarrhea-predominant illness with longer latency. ### Mnemonic: CPE = "Crampy Pain + Enterotoxin" [cite:Jawetz, Melnick & Adelberg's Medical Microbiology 28e Ch 12]