Survey of enterohemorrhagic Escherichia coli (EHEC) and its antibiotic resistance among children less than 5 Years in Marvdasht

Enterohemorrhagic Escherichia coli (EHEC) strains are one of the most important enteric pathogens which cause of the food-borne disease in humans. The purpose of this study was to survey the prevalence of diarrhea arising from this bacteria and infection source and antibiotic resistance of isolated strains in children under 5 years old in Marvdasht. In this descriptive study, Stool samples of under 5 years old children in Marvdasht were collected. After enrichment in specific culture media and evaluation sorbitol fermentation and their β-glucoronidase activity (MUG test) with specific antisera, the isolation of EHEC O157:H7 strain was confirmed. Then, virulence genes verotoxin, intimin and hemolysin with multiplex PCR and antibiotic resistance strains with disk diffusion method were tested. Also, getting infection with water, food and animal contact was evaluated. Out of 615 cases, 89 sorbitol negative colonies isolated which 7 strains O157 (1.14%) confirmed with antisera. Of virulence genes, only 1 of the isolated strains (0.16%) had stx1 and eaeA genes. All isolated bacteria had resistance to penicillin, ampicillin and erythromycin. There was no significant relation between isolated EHEC strains and the different seasons of the year. Hospital based surveillance to estimate the burden of EHEC strains in clinical centers in all less than 5 years old children with acute gastroenteritis and studies on etiology and genotyping of this bacterium in other parts of the country are recommended.