VIRULENCE AND ANTIMICROBIAL RESISTANCE GENES OF Escherichia coli IN READY TO EAT SANDWICHES IN SHARKIA GOVERNORATE

Abstract

Ready to eat food has been associated with some epidemics of foodborne illness all over the world. This study was designed to evaluate the microbial quality of ready to eat (RTE) sandwiches in Sharkia Governorate with special reference to virulence and antibiotic resistance genes of Escherichia coli ( E. coli ). One hundred and eighty RTE sandwiches containing meat (shawerma, kofta, sausage and hawawshi), chicken (chicken shawerma, pane, shish tawook, grilled chicken) and fish (grilled Tilapia nilotica, grilled Mugel cephalus , fried shrimp and fried fillet), fifteen of each were randomly collected from restaurants in Sharkia Governorate. Bacteriological examination revealed that the mean values of aerobic plate count (APC) ranged from 1.23×10 4 to 8.4×10 5 CFU/g and of total coliform count indicated by most probable number (MPN/g) ranged from 0.09×10 2 to 6.95×10 2 . E. coli percentages ranged from 6.7% to 26.7%. Serotyping of E. coli strains revealed five serotypes (O 153 : H 2 , O 78 , O 127 : H 6 , O 91 : H 21 and O 26 : H 11 ) by different percentages, O 26 : H 11 was the most common one (31.6%) and O 153 : H 2 was the lowest one (5.3%). All recorded isolates showed 100% antibiotic resistant to both erythromycin and amoxicillin – clavulanic acid. It was further found that eae A gene present in all isolated serotypes except O 153 : H 2 while Shiga toxin ( Stx 1 and Stx 2) were not detected at all, also found that resistant E. coli isolates to amoxicillin-clavulanic acid and erythromycin possessed bla TEM , mph A resistance genes (100%). Current results point to that RTE sandwiches in Sharkia Governorate are potential vehicles of antimicrobial-resistant E. coli among other possible foodborne pathogens with public health significance. Key words: ready-to-eat; aerobic plate count; E. coli ; coliform; resistance genes