The isolation and characterization of diarrheagenic Escherichia coli strains from sources of meat in Bannu, KP, Pakistan

Background: Microbial contamination of meat sources including undercooked meat products is regarded as an emerging means of food-borne disease outbreaks. Diarrheagenic Escherichia coli (DEC) is an important agent of infectious diarrhea and is constantly evolving; hence its periodic monitoring is always required. Escherichia coli (E. coli) pathotypes including food-borne pathogens such as Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC) cause hemolytic uremic syndrome and fatal infant diarrhea. Herein, we focused on microbial contamination, especially E. coli pathotypes of retailed meat sources in the Bannu district of Khyber Pakhtunkhwa, Pakistan. Methods: Two hundred carcass samples from perineal area, flank, brisket, and neck region were collected from butcheries located in B.D Kp Pakistan using sterile bags. These different samples were inoculation on differential media for biochemical characterization and multiplex PCR assays. Results: We found that the percentage of contamination in beef by E. coli serotype O157:H7 was in beef meat 20.9%, chicken meat 0.00, and goat meat 34%. Furthermore, for confirmation of STEC, the stx1 and stx2 genes were amplified using the isolated E. coli strains. Prevalence of 21.5% and 5.9% were recorded for Shiga toxin-producing E. coli strains from sheep and goats respectively. The proportion of EPEC isolated from goat and chicken were 75% and 62.5% for strains isolated in samples. Enterotoxigenic E. coli were positive for heat-labile toxin (LT) genes compared to 37.5% having heat-stable toxin (ST) producing genes. Among ninety-seven percent of E. coli pathotypes showed resistance to tetracycline, while the 91% showed resistance to ciprofloxacin. Conclusions: To reduce food-borne pathogen contamination, novel, practical, and efficient food safety control and surveillance technologies for multi-drug resistant food-borne pathogens are required.