Evaluation of enterohemorrhagic Escherichia coli of outbreaks of foodborne disease by molecular method

Background and Objective: The most common enterohemorrhagic Escherichia coli strain is the O157: H7 serotype, which is one of the most important intestinal pathogens and can cause complications such as hemorrhagic colitis, hemolytic uremic syndrome and acute renal failure. The aim of this study was to evaluate the enterohemorrhagic Escherichia coli causing molecular outbreaks of foodborne illness in Iran. Methods: In this descriptive cross-sectional study, 189 fecal swab specimens were examined during April to September 2018. All suspected isolates were tested for biochemical tests. The isolates were confirmed by molecular PCR and evaluated by antimicrobial susceptibility tests. Results: From 189 stool swab samples studied, 98 Escherichia coli isolates were detected based on phenotypic tests. Most of the outbreaks occurred in summer and the prevalence of enterohemorrhagic Escherichia coli was 24.5%, which 4% of them were non-O157H7. Most patients were between 1 and 12 years of age and the highest antibiotic resistance to cotrimoxazole and chloramphenicol was observed at 80% and 79%, respectively. Conclusion: This study showed an increase in enterohemorrhagic Escherichia coli with 24.5% and an increase in antibiotic resistance to the antibiotics of chloramphenicol, cotrimoxazole and carbapenems. Increased resistance to imipenem and meropenem antibiotics makes it difficult to treat beta-lactamase-resistant strains.