Prevalence, Virulence and Antibiotic Resistance of Escherichia coli Isolated From Fresh, Chilled and Frozen Retail Marketed Beef in Egypt

Existance of antimicrobial-resistant pathogenic E. coli in meats is of great concern due to its harmful effects on human health. Therefore, this study aimed to detect pathogenic E. coli in retail beef samples. Herein, seventy-five retail beef samples representing 25 from each fresh, chilled and frozen samples were randomly collected from various butcher shops located in EL-Minya and Beni-Suef governorates. Collected samples were assessed for their microbiological quality using the most probable number technique for enumeration of coliforms, fecal coliforms and E. coli. Additionally, E. coli isolates were subjected to biochemical, serological and molecular identifications. Antibiotic sensitivity test was conducted by disc diffusion method to evaluate the antibiotic resistance of the isolates. The results showed that the incidence of E. coli pathogen in the fresh, chilled and frozen beef samples was 16%, 4% and 4% respectively. The identified serovars in fresh samples were O44: K74 (8%), O111: K58 (4%), and O55:K59 (4%), in chilled was O44:K74 (4%) and in frozen samples was O25:K11 (4%). Genetically, the most prevalent gene was EaeA, followed by ChuA, AdrA, LuxS, and Stx1 with percentages accounted for 100%, 83%, 83%, 83%, 83% and 16%, respectively. All the isolated strains were multi drug resistant (MDR) when examined against different types of antibiotics. It was concluded that the existence of virulent E. coli in meat is widely distributed which has a public health significance and need periodical evaluation of the hygienic status of Egyptian meat markets to prevent food poisoning and public health hazards.