Prevalence of Quinolone Resistance Genes in Klebsiella pneumoniae Strains Isolated from Hospitalized Patients During 2013 - 2014

Background: The increasing emergence of resistance among clinical isolates of Klebsiella pneumoniae (K. pneumoniae) has limited the therapeutic options used to treat infections caused by these bacteria. Objectives: The aim of this study was the molecular detection of quinolone resistance genes acrA, acrB, qepA, and aac(6’)-Ib-cr in K. pneumoniae strains isolated from hospitalized patients in selected hospitals in Tehran during 2013 - 2014. Methods: One hundred and seventeen strains of K. pneumoniae were isolated between August 2013 and March 2014 from hospitalized patients in Taleghani hospital, Mofid children’s hospital, and Imam Hossein hospital in Tehran. Antimicrobial susceptibility tests were performed using disk diffusion and broth microdilution methods based on CLSI guidelines. The identification of the genes that encode efflux pumps acrA, acrB, qepA, and aac(6’)-Ib-cr was done using the PCR technique. Results: Antimicrobial susceptibility tests showed that colistin and tigecycline had the best effect against clinical isolates of K. pneumoniae. The PCR assay detected the acrA and acrB genes in 110 (94%) and 102 (87%) isolates, respectively. Additionally, the qepA and aac(6’)-Ib-cr genes were detected in 5 (4%) and 100 (85%) isolates, respectively. Conclusions: The prevalence of the acrA, acrB, qepA, and aac(6’)-Ib-cr genes in K. pneumoniae, which causes resistance to fluoroquinolones, in this study is cause for concern. Based on our results, accurate identification of resistant Gram-negative bacteria such as K. pneumoniae and detection of its susceptibility to common antibiotics could lead to proper treatment and control of resistant nosocomial infections.