Evaluation of the frequency of Escherichia coli pathogroups in Brassica oleracea cultivars

Abstract

Background and Objectives: Pathogenic diseases resulting from microbial contamination of food have been widely distributed in many parts of the world. Among these, Escherichia coli is one of the most important foodborne pathogenic bacteria. Diarrhea is one of the major causes of children’s death in developing countries, with approximately 2 million deaths annually. The current study aimed to determine the frequency of diarrheagenic E. coli pathotypes such as Enteropathogenic E. coli (EPEC), Enterotoxigenic E. coli (ETEC), Enteroaggregative E. coli (EAEC), and Shiga toxin-producing E. coli (STEC) in Brassica oleracea cultivars in order to provide information on the assessment of diarrheagenic E. coli pathogenesis risk. Materials and Methods: 100 samples of vegetables were collected in Tehran, including cabbage, cauliflower, broccoli and Brussels sprouts. After homogenizing samples, enrichment was done in the EC broth medium. Five colonies of pure culture were used for DNA extraction. Pathotypes were identified by PCR using virulence genes. Results: The results showed that the prevalence of diarrheagenic E. coli strains was 7%. The EPEC prevalence was 3%, All EPEC isolates were atypical. The ETEC frequency was 3%, And the EAEC prevalence was 1%. Conclusion: These findings indicated that Brassica oleracea cultivars could be consideredas a source of contamination with diarrhea-causing E. coli strains.

Keywords

• Diarrheagenic Escherichia coli;
• Virulent genes;
• Raw vegetables;
• Brassica oleracea