Occurrence of plasmid mediated fluoroquinolone resistance genes amongst enteric bacteria isolated from human and animal sources in Delta State, Nigeria

Plasmid mediated quinolone resistance (PMQR) is a public health challenge arising among other things, from indiscriminate use of the floroquinolones (FQr) prophylactically in animal husbandry. This study examines the occurrence of PMQR genes amongst enteric bacteria isolated from human and animal sources. A total of 720 (360 stool and 360 fish pond water/poultry litter) samples were examined for fluoroquinolone resistant (FQr) bacteria. Percentage FQr was generally higher among human isolates than isolates from animals. Proportion of PMQR amongst FQr isolates were (1.05 and 4.32) % for E. coli from human and animal sources. For Salmonella spp., Shigella spp., Klebsiella spp. and Aeromonas spp., percentages PMQR were 0.00 & 6.93, 0.00 & 6.38, 4.26 & 5.26 and 0.00 &3.03 for human and animal sources respectively, for the isolates. The PMQR genes: qnrA, qnr B, qnr S and qep A were 11, 15, 7 and 1 amongst a total of 1018 FQr and 29 PMQR isolates respectively. The aac (6′)–Ib-cr gene was not detected in this study. Approximate Plasmid bands of PCR amplicon for qnr A, qnr B, qnr S and qep A respectively were established. The proportion of PMQR genes especially among isolates from animal sources is of public health concern due to the higher possibility of a horizontal FQ resistance transfer to humans.