ABSTRACT
BA C T E R I A L diarrheal pathogens may be divided into two groups, based on their pathogenic mechanisms: (1) The noninvasive group exemplified by on the one hand Vibrio cholerae and enterotoxigenic Escherichia coli (ETEC), which cause disease by adhering to the small intestinal mucosa and secreting potent enterotoxins, and enteropathogenic E. coli (EPEC), which colonize and partially destroy the intestinal epithelium without invading it. And (2) The invasive group, typified by Salmonella and Shigella, has invasion of the intestinal mucosa as a central feature, which in the case of Salmonella may proceed to systemic dissemination (typhoid fever), which is rarely seen during Shigella infections.
