Isolation EPEC strains in the region of Thrace, Greece

Abstract number: 1733_80

Alepopoulou E., Panopoulou M., Dala V., Chatzimichail A., Ritis K., Kartali S.

Objective: Enteropathogenic E. coli (EPEC) is an important category of diarrhoeagenic E. coli which links to infant diarrhoea in the developing world and sporadic cases of diarrhoea in industrial countries. EPEC damage the bowel mucosa with characteristic mechanism (attaching and effacing lesion) mediated by a protein encoded by the eae chromosomal gene.

Methods: Two hundred fifteen stool specimens were examined for EPEC. One hundred sixty five samples proceeded from patients with diarrhoea (group A) and 50 from healthy individuals (group B). Stool specimens or rectal swabs were inoculated on MC agar and incubated at 37°C overnight. Five colonies of E. coli isolated on MC agar were picked. The biochemical identification of the strains was performed by automated system VITEK 2 (bioMérieux) and serotyping by slide-agglutination methods for serotypes O111, O55, O26, O86, O119, O127, O125, O126, O128, O124, O114, O142 (BioRad). The presence of eae gene was detected by PCR that contains primers for eae E. coli gene. The PCR products 384 bp were analysed by electrophoresis in 2% agar gel.

Results: From 215 stools 1207 strains E. coli were examined. EPEC were recovered from 22 (10.2%) stool specimens, 11 (5.1%) of them were from children and 8 (3.7%) from adults (group A), though 2 and 1 strain respectively from group B (control). The EPEC strains encountered in this study belonged to 5 different serotypes of E. coli: O127–8 (36%), O26–5 (23%), O126–4 (18%), O125–4 (18%) and O55–1 (4.5%). These strains did not have the eae gene. However, one strain (0.6%) from group A that yielded gene eae, did not ferment sorbitol and has been isolated from stool of an adult patient with diarrhoea.

Conclusion: The 5.1% EPEC strains were isolated from children and isolation rate is in agreement with those of other investigations. However, according to the decision of the Second International Symposium on EPEC in 1995: strains with A/E histopathology and absence of Shiga toxin should be called EPEC. Consequently, the rate of isolation of EPEC in this study was much lower (0.6%), as only one from the 165 samples has the eae gene. The detection of pathogenic genes altered in high degree the rates of isolation of EPEC and modifies the epidemiologic data of various regions.