AGE-SPECIFIC PREVALENCE OF ESCHERICHIA-COLI WITH LOCALIZED AND AGGREGATIVE ADHERENCE IN VENEZUELAN INFANTS WITH ACUTE DIARRHEA

To evaluate the epidemiological significance of HEp-2 cell-adherent Es cherichia coli isolates in diarrheal disease, we performed a study wit h 513 Venezuelan infants with diarrhea and 241 age-matched controls to determine the prevalence of enteropathogenic E. coli (enteroadherent E. coli, enterotoxigenic E. coli, enteroinvasive E. coli, and enterohe morrhagic E. coli) and their correlation with O:H serotypes. E. coli i solates exhibiting localized and aggregative adherence in the HEp-2 ce ll assay were significantly more frequently isolated from the patients (8.5 and 26.9%, respectively) than from the controls (1.7 and 15%, re spectively). This difference was significant for the group 0 to 2 mont hs of age but not for older infants. Regardless of age, E. coli isolat es with diffuse adherence were found at similar frequencies in both th e patients and the controls. A striking correlation between classic O serogroups and localized adherence was also observed. These findings c onfirm the pathogenic role of E. coli with localized and aggregative a dherence in diarrheal disease, as well as the epidemiological importan ce of O:H serotyping for characterizing localized-adhering E. coli.