Prevalence of Aac(6’)-Ib-Cr and Qepa Genes among Quinolone    Resistant Uropathogens Isolated from Asymptomatic Female Students of a Northern University on Nigeria.

Introduction: Quinolone resistance are commonly chromosomally encoded but plasmid mediated quinolone resistance (PMQR) has been reported. This study aimed to assess the prevalence of aac (6’)-Ib-cr and qepA genes among quinolone resistant uropathogens isolated from asymptomatic female students of a northern university.

Method: A total of 400 urine samples were examined, uropathogens were isolated from the urine samples, identified using Microgen GNA-ID kit and tested for antibiotics susceptibility by the modified Kirby-Bauer disc diffusion method. DNA were extracted from quinolone resistant isolates and presence of aac(6’)-Ib-cr and qepA genes were determined using PCR.

Result: A total of 148 Enterobacteriaceae were isolated from the urine samples positive for bacteriuria. The organisms consisted mainly of Klebsiella spp. (19.6%), Acinetobacter spp. (19.6%), Enterobacter spp. (17.6%) and Escherichia spp. (11.5%). Identification to species level revealed that the most prevalent organisms were Acinetobacter baumannii (13.5%), Klebsiella oxytoca (11.5%), Serratia marcescens (8.1%), Klebsiella pneumonia (7.4%), Enterobacter agglomerans (7.4%), Salmonella arizonae (6.8%) and Escherichia coli (6.8%). Antibiotics susceptibility showed that 18/148 (12.2%) of the isolates were resistant to quinolones. The highest level of resistance to Quinolones was seen with Ciprofloxacin (12%) followed by Pefloxacin, Norfloxacin and Levofloxacin (6%). 10 (55.6%) of the isolates showed increased susceptibility to the same quinolone antibiotics used for antibiotic susceptibility testing to which they were resistant after plasmid curing indicating that resistance was carried on plasmids. Molecular analysis on the 10 cured isolates showed the amplification aac(6’)-Ib-cr gene and qepA gene on electrophoretic gel. 70% of the isolates expressed the gene aac(6’)-Ib-cr of 482 bp and 70% of the isolates expressed the gene qepA of 199 bp. The report shows that there is an occurrence of PMQR among the study population.