Certified Professional Food Safety (CP-FS) Practice Exam

Which bacteria is primarily responsible for most cases of diarrheal illness?

1. Staphylococcus aureus

2. Campylobacter jejuni

3. Bacillus cereus

4. Clostridium botulinum

The correct answer is: Campylobacter jejuni

Campylobacter jejuni is primarily responsible for most cases of diarrheal illness because it is one of the most common bacterial pathogens associated with foodborne infections. This bacterium is often linked to the consumption of undercooked poultry, unpasteurized milk, and contaminated water. Its ability to survive and multiply in the intestines leads to enteritis, which presents as diarrhea, abdominal cramping, and fever. Campylobacter jejuni's prevalence in food sources and its effective colonization of the intestinal tract make it a significant public health concern, particularly in areas where proper food safety practices are not strictly followed. Effective control measures, such as thorough cooking of meat, proper hygiene, and sanitation, are critical in preventing illness caused by this bacterium. In contrast, while other bacteria listed can cause foodborne illnesses, their impact on diarrheal illness specifically is less significant compared to Campylobacter jejuni. For instance, Staphylococcus aureus is more often associated with food poisoning cases that lead to vomiting rather than diarrhea. Bacillus cereus can cause gastrointestinal problems, but its effects often depend on the type of toxin produced and the time-related factors of food consumption. Clostridium botulinum primarily causes botulism, which is