MOLECULAR IDENTIFICATION OF E. COLI O157:H7, VIRULENCE GENES AND QUINOLONE / FLUOROQUINOLONE RESISTANT GENES AMONG E. COLI ISOLATES FROM RETAILED MEAT IN IBADAN, SOUTHWEST NIGERIA

Abstract

Escherichia coli is classified based on their pathogenicity factor, the strain E. coli O157:H7 is implicated in diarrhoea leading to haemolytic uremic syndrome. Therefore this study identified E. coli O157:H7, virulence and quinolone/fluoroquinolone resistant genes in Escherichia coli isolates from meat. Isolates of Escherichia coli from meat were identified by standard laboratory methods using Microbact GNB 12E (Oxoid), E. coli O157:H7 was identified by serotyping and the presence of virulence gene was determined by molecular methods. Antibiotic susceptibility of E. coli and quinolone/fluoroquinolone resistance (qnr) genes were determined using disc diffusion and molecular methods respectively. Out of the 130 E. coli identified, 72 (55.4%) were resistant to at least one or more of the antibiotics tested including quinolone/fluoroquinolones. E. coli O157:H7 were detected serologically 5 (3.9%) and by the multiplex PCR 8 (6.2%) out of which, 2 (25%) carried eaeA, hly, rfbE and flich genes, 7 1(12.5%) carries eaeA, rfbE and hly genes, 1(12.5%) carries hly, rfbE, flich and stx2 genes, 3(37.5%) 7 carries hly, rfbE and flich genes, 1 (12.5%) carries rfbE and hly genes while none of the isolates have 7 stx1 genes. Quinolone resistant genes (qnr) was harboured by 41 (56.9%) of which 5 (3.9%) and 36(27.7%) isolates carried qnrA and qnrB, respectively. Only 2 (50%) of the E. coli O157:H7 harbour qnrB, no qnrA was detected. The E. coli isolated from meat carries virulence and qnr resistance gene which could be potential vehicles for spread of multi-drug resistant to humans.