PREVALENCE OF Aac (6’)-ib-cr and QepA GENES AMONG QUINOLONE RESISTANT Escherichia coli ISOLATES FROM URINE SAMPLES IN YENAGOA METROPOLIS, BAYELSA STATE, NIGERIA

Quinolone resistance are commonly chromosomally encoded but plasmid mediated quinolone resistance has been reported. Can Escherichia coli strains harbor Quinolone resistance genes? This study was carried out between January, 2019 and October 2019, to determine the presence of aminoglycoside acetyltransferase (aac(6’)-ib-cr) and quinolone efflux pumps (QepA) genes in quinolone resistant Escherichia coli strains from urine samples in Bayelsa state, Nigeria. A total of 250 midstream urine samples collected (from the patients with Urinary Tract Infection cases attending Niger Delta Teaching Hospital, Okolobiri and Federal Medical Centre, Yenagoa) and examined using Cysteine Lactose Electrolyte Deficient and Eosin Methylene Blue agar, include 164(65.6%) females and 86(34.4%) males. Pure isolates of Escherichia coli were subjected to antibiotics susceptibility testing using modified Kirby Bauer disc diffusion method and Mueller Hilton agar. Out of 250 samples analyzed 22/250 (8.8%) were positive to Escherichia coli 13 (59.1%) females and 9(40.9%) males. Twelve (12) quinolone resistant isolates were subjected to genomic DNA extraction by boiling method to determine the presence of aac(6’)-ib-cr and qepA genes using an AB19700 applied Bio-system Thermo-cycler.. Ofloxacin was the most potent drug with percentage susceptibility of 64, this was followed by Streptomycin 54.5%; Pefloxacin 41%, Septrin 36%, Ciprofloxacin 32%; Gentamycin 27%, Augmentin 13.6%, Ceporex 12%, Nalidixic acid 4.5% and Ampicillin 4.5%. The isolates were highly resistant to quinolone class of antibiotics, Nalidixic acid, with percentage resistance of 95.5, followed by Ciprofloxacin 68%, Pefloxacin 59% and Ofloxacin 36%. Out of twelve (12) quinolone resistant Escherichia coli isolates subjected to molecular analysis, 6 (50%) and 1(8.3%) expressed the presence of aac(6’)-ib-cr on 480 base pair and QepA genes on 800 base pair respectively giving a summation of 7(58.3%) isolates in all. Statistical analysis showed that there is a significant difference in the potency of the antibiotics used in this study at P= .05, but no significant difference between the resistant genes detected which made the null hypothesis acceptable at P<0.05. In conclusion, these findings have revealed the difficulties clinician might encounter in the treatment of urinary tract infection caused by Escherichia coli using quinolone class of antibiotics.