Adherence patterns in HEp-2 cells of Escherichia coli strains isolated from contaminated rivers in Havana

Abstract

Introduction: Adherence is crucial to the development of most Escherichia coli infections. Three different adherence patterns have been described for pathotypes of this species: localized, diffuse and aggregative adherence, based on the specific clinical pathogenic processes they bring about. However, few studies have been conducted about in vitro adherence phenotypes of E. coli isolated from the environment.

Objective: Determine the adherence phenotypes of E. coli strains isolated from freshwater ecosystems in Havana.

Methods: An analysis was conducted of 108 E. coli strains isolated from the rivers Almendares, Quibú and Luyanó in Havana. Determination was made of the adherence pattern by adherence assays in HEp-2 cell line cultures, as well as of the serotype for each strain.

Results: Of the E. coli strains isolated, 25% were adherent and 75% were not. Twenty-two strains displayed the typical diffusely adherent pattern and five displayed aggregative adherence. Strains exhibiting the two adherence patterns were found in the three rivers evaluated. The strains contained 24 different serotypes.

Conclusions: The environmental E. coli strains circulating in these ecosystems were found to have adherent characteristics whose pathogenicity implies a potential risk to human health, particularly in childhood.