Incidence of Heat-Labile Toxin (LT) Producing Enterotoxigenic Escherichia coli Mediated Diarrheal Disease in Egyptian Children under 5 Years Presenting to Tanta University Hospital

Background: Enterotoxigenic E. coli (ETEC) is under recognized but an important cause of diarrhea in the developing countries. It is the most frequent bacterial cause of diarrhea in children and adults living in these areas but is most frequently seen in children. We aimed to determine the incidence of LT producing ETEC in cases of acute diarrhea in children under 5 years, to detect the phenotypic characters of LT producing ETEC and to investigate the presence of the heat labile toxigenicity gene in isolated E. coli strains.

Methodology: This study was carried out on 100 children with acute diarrhea. After history taking and clinical examination, diarrheal stool was used for phenotypic characterization of ETEC through isolation of E. coli by culture followed by microscopic examination then biochemical reactions using API 20 E. LT producing ETEC strains were detected using Phadebact R ETEC-LT test. Antibiotic sensitivity of the positive strains was done followed by genotypic characterization through detection of heat-labile toxigenecity gene (elt) in isolated E. coli strains by polymerase chain reaction.

Results: LT producing ETEC was isolated in (8%) of studied children with a higher sensitivity of PCR than coagglutination test. There was no significant effect on ETEC incidence regarding sex or age; it was significantly lower in breast fed infants with a seasonal peak during summer and early autumn. It showed sensitivity to ceftriaxone (87.5%) and resistance to trimethoprim-sulphamethoxazole (75%), ampicillin (62.5%) and gentamycin (50%).

Conclusion: Rapid screening test is a useful addition to laboratory diagnostic procedures in regions where ETEC is endemic. PCR has high levels of sensitivity and specificity and able of detecting both expressed and silent genes. Sensitivity of isolates to ceftriaxone (87.5%) suggests that this antibiotic is a rational choice for the treatment of prolonged childhood diarrhea in which ETEC is a primary etiologic causative agent.