Typical and atypical enteropathogenic Escherichia coli.

Luiz R Trabulsi,Tânia A Tardelli Gomes,Rogéria Keller

doi:10.3201/eid0805.010385

Abstract

Typical and atypical enteropathogenic Escherichia coli (EPEC) strains differ in several characteristics. Typical EPEC, a leading cause of infantile diarrhea in developing countries, is rare in industrialized countries, where atypical EPEC seems to be a more important cause of diarrhea. For typical EPEC, the only reservoir is humans; for atypical EPEC, both animals and humans can be reservoirs. Typical and atypical EPEC also differ in genetic characteristics, serotypes, and virulence properties. Atypical EPEC is more closely related to Shiga toxin–producing E. coli (STEC), and like STEC these strains appear to be emerging pathogens.

Highlights

Typical and atypical enteropathogenic Escherichia coli (EPEC) strains differ in several characteristics
Typical EPEC serotypes have traditionally been associated with outbreaks of infantile diarrhea, and, the first EPEC strains isolated in different countries were of serotypes O55:H6 and O111:H2 [32]
The additional virulence characteristics of the eae+, EPEC adherence factor (EAF)+ strains have not been studied, but recently we investigated the virulence profile of 49 different eae+, EAF- strains isolated from children with diarrhea in São Paulo

Summary

Typical and Atypical Enteropathogenic Escherichia coli

Typical and atypical enteropathogenic Escherichia coli (EPEC) strains differ in several characteristics. The majority of typical EPEC strains fall into certain well-recognized O:H serotypes” [10] According to this definition, the basic difference between typical and atypical EPEC is the presence of the EAF plasmid in the first group of organisms and its absence in the second. Some serotypes are not so readily classified, mainly those that include Stx-producing strains, of which the most frequent are serotypes O26:H- and H11, and O111ac:[H8] (considered by some authors as EHEC or STEC) [1] These serotypes and others with properties similar to those of O128:H2 are not true atypical EPEC or STEC serotypes but rather are heterogeneous serotypes that include different clones or genetic lineages. Other characteristics that may complicate distinguishing typical from atypical EPEC are related to the EAF

Strains Typical

Intimin types

Prevalence in Developing and Industrialized Countries

Findings

Conclusion