Which of the following pathogens are associated with watery diarrhea after an incubation period of 8 to 14 hours?: (A) Rotavirus and Norwalk virus, (B) Shigella and Salmonella, (C) S. aureus and Bacillus cereus, (D) Bacillus cereus and Clostridium perfringens
Answer is D. Bacillus cereus and Clostridium perfringens Bacillus cereus strains can produce two different toxins: a heat stable toxin that can lead to an illness after 2 to 7 hours and a heat-labile toxin that causes disease manifestations 8 to 14 hours after ingestion. The syndrome of Clostridium perfringens diarrhea usually occurs 8 to 14 hours after ingestion of the preformed toxin.