Multiple Resistance in Clinical Isolates of Escherichia coli and Plasmid-mediated Quinolone Resistance Genes

Abstract

Quinolone antibiotics have been commonly used to treat cases of multiple antibiotic resistance. Unfortunately, quinolone antibiotics have so much been resisted by infectious bacterial agents. This study aimed to evaluate the susceptibility of some clinical isolates of E. coli to some commonly used quinolone antibiotics and the determination of the plasmid-encoded quinolone resistance genes. Our results showed the plasmid quinolone-resistance genes in the following prevalence: qnr genes: qnr S (71.4 %); qnr B (15.4 %); qnr S and B (12.1 %); aac (6) lb-cr (4 %); Efflux genes: oqxA (7.7 %); oqxB (25.3 %); qepA (12.1 %); oqxA and oqxB (5.5 %). We conclude that there is a high frequency of Plasmid-mediated quinolone resistance genes in Escherichia coli isolates from clinical samples in South-Eastern Nigeria. These could be responsible for the high incidence of quinolone resistance reported in Enugu. There is a need for whole-genome sequencing to map out all resistance genes.