Abstract

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Enteropathogenic Escherichia coli (EPEC), is among the most important pathogens infecting children worldwide and one of the main causes of diarrhoea. EPEC infection is often under diagnosed during routine microbiological analysis, especially in resource constrained settings and therefore the use of serological and molecular test could help to determine the distribution of EPEC and its clinical significance. The study was carried out to investigate the occurrence of EPEC as a cause of diarrhoea in children younger than 5years of age and to detect their virulence genes. During the study period, a total of 280 faecal specimen from children with diarrhoea and 20 from healthy children were collected and screened for E.coli using biochemical tests. The confirmed E. coli isolates were serologically tested with EPEC polyvalent and monovalent antisera to detect EPEC serotypes. The EPEC serotypes were screened for the presence of the attaching and effacing (eaeA) and bundle- forming pilus (bfpA), gene by PCR assay. Furthermore, antimicrobial susceptibility pattern of the EPEC serotypes were determined by Kirby Bauer disc diffusion method. The isolates were also screened for Extended Spectrum βeta-lactamase (ESBL) production by double disc synergy. The study revealed that EPEC was detected in 19 (6.7%) of the test samples but negative in the control group. The EPEC serotype O55: K59 (B5), had the highest frequency of occurrence. The bfpA and eaeA genes were detected in 31.6% and 15.7% of the EPEC isolates respectively. Typical EPEC (eaeA+, bfpA+) was detected in one isolate, while atypical EPEC was detected in seven isolates. The antimicrobial susceptibility revealed that EPEC isolates were highly resistant to ampicillin (100%), tetracycline (84.2%), and trimethoprim (89.4%) but were sensitive to ciprofloxacin (95%), ceftriaxone (84.2%), ceftazidime (79.0%) and amoxicillin-clavulanate (79.0%). Three (3) isolates were found to produce ESBL. The investigation including the use of serotyping and molecular technique, are necessary to allow precise identification and epidemiological study of these pathogens. Multidrug resistant EPEC can be associated with infantile diarrhoea

Keywords: Enteropathogenic E.coli, Typical EPEC, Atypical EPEC, Bundle- forming pilus, Intimin, Diarrhoea