Abstract

The current work aimed to determine the prevalence of Escherichia coli in fresh ground beef purchased from butchers' shops in Suez Governorate, Egypt, and the antibiotics susceptibility pattern of the isolated bacteria. E. coli was isolated and detected on tryptone bile glucuronide agar (TBGA) plates as chromogenic selective medium for this species. The sensitivity and resistance of the isolated bacteria to antibiotics were performed according to the National Committee for Clinical Laboratory Standards guidelines (NCCLS). A total of 299 bacterial isolates were recovered from 130 ground beef and E. coli had the highest frequency of occurrence (81.5%). The isolated enteric bacteria were identified phenotypically and genotypically as Serratia marcescens, E. coli, Enterobacter cloacae and Klebsiella pneumoniae and deposited in the GenBank nucleotide sequence database under accession numbers KU237235, KU237236, KU237237 and KU237238, respectively. Antibiotic susceptibility test showed that the four isolated species were susceptible to norfloxacin, pefloxacin, kanamycin and ceftriaxone, and resistant to clindamycin and the other tested antibiotics showed different susceptibility pattern with each tested species. Precautions and strict hygienic measures should be taken during the processing stages of ground beef in order to avoid contamination by enteric bacteria.

Key words: Contamination, Enterobacteriaceae, genotype, resistance, susceptibility, meat.