Frequency of qepA and aac(6')-Ib-cr Plasmid-Mediated Quinolone Resistance Genes in Klebsiella Pneumoniae isolated from Patients with Urinary Tract Infection in Yazd City, Iran

Klebsiella pneumoniae is a common bacterium in nosocomial infections, especially urinary tract infection. Considering rising in fluoroquinolone resistance and lack of accurate reports of frequency of plasmid-mediated genes, this study aimed to determine the frequency of qepA and aac(6')-Ib-cr genes among Klebsiella pneumoniae isolated from urinary tract infection in Yazd City, Iran.
In this cross-sectional study, 70 Klebsiella pneumoniae strains were isolated from the urine cultures during 9 months (March to November 2014). Antibiotic resistance pattern for common fluoroquinolones were determined via disk diffusion method and the minimum inhibitory concentration (MIC) via Epsilometer test (Etest). Polymerase chain reaction (PCR) method was used for detection of qepA and aac(6')-Ib-cr genes by specific primers. The results were analyzed using SPSS software.
Findings: Disk diffusion results showed that the highest and lowest resistance rates were for nalidixic acid (40.0%) and levofloxacin (27.1%), respectively. According to the minimum inhibitory concentration, 45.7% and 38.6% of the isolates were identified as resistant for nalidixic acid and ciprofloxacin, respectively. aac(6')-Ib-cr gene was detected in 21 isolates (30%); but qepA gene was not detected in any of isolates (0%).
The results of this study indicate that resistance to common fluoroquinolones is gained. High frequency of aac(6')-Ib-cr gene is an alarm for the region. Therefore, antimicrobial resistance monitoring of this bacterium should be reviewed seriously before initiating treatment and studies about the chromosomal and plasmid-mediated quinolone resistance determinants should be done regularly.