ABSTRACT
The pathogenesis and disease symptoms of several pathogens associated with foodborne and waterborne gastroenteritis are somewhat different from classical food poisoning or foodborne infection caused by the pathogens described in Chapters 25 and 26. Although the differences are not always very clear, in this chapter, the gastroenteritis caused by Clostridium perfringens, Bacillus cereus, Vibrio cholerae, and enterotoxigenic Escherichia coli is described as a toxico-infection. The first two are Gram-positive spore-formers, and the last two are gram-negative short rods. For each pathogen, importance, characteristics, nature of toxins, food association, and control measures are discussed. For some, detection methods and analysis of outbreaks are also included. The following are some characteristics of foodborne toxico-infection:
For spore-formers, ingestion of large numbers of live vegetative cells is usually necessary.
Vegetative cells of spore-formers do not multiply in the digestive tract but sporulate and release toxins.
For gram-negative bacteria, live cells can be ingested in moderate numbers.
Gram-negative cells rapidly multiply in the digestive tract.
Many cells also die, releasing toxins.
Toxins of both groups produce the gastroenteritis symptoms.
