ESCHERICHIA COLI | Enteroinvasive Escherichia coli: Introduction and Detection by Classical Cultural and Molecular Techniques

Abstract

Enteroinvasive Escherichia coli (EIEC) occupy a somewhat-distinct niche as it has many biochemical characteristics of E. coli and yet it is pathogenetically similar to Shigella. The pathogen causes bacillary dysentery but unlike shigellae, appears to be better adapted to survive in the environment and not to be restricted to host dependency for survival. Although EIEC and Shigella species are considered to compose a single pathovar within the genus E. coli, these pathogens most likely arose from different E. coli lineages. They do share a common evolutionary event, the acquisition of a large virulence plasmid. An overall identification scheme for EIEC would include amplification of the ipaH gene by PCR, maintained by both EIEC and Shigella species; biochemical tests; and serological assays using antisera to distinguish EIEC from noninvasive E. coli as well as Shigella. As a pathogen, the occurrence of food-related outbreaks is uncommon in industrial and developing countries but occasionally does cause sporadic cases.