Detection of OqxAB and QepA Efflux Pumps and Their Association with Antibiotic Resistance in Klebsiella pneumoniae Isolated From Urinary Tract Infection

Abstract

Background: The emergence and spread of drug resistance among Klebsiella pneumoniae clinical isolates have limited the treatment options for these bacteria. Efflux pumps are considered as one of the key mechanisms of antibiotic resistance in K. pneumoniae isolates. Objectives: The present study aimed to detect oqxA, oqxB, and qepA efflux genes in K. pneumoniae isolated from urinary tract infection (UTI) and survey their association with antibiotic resistance. Methods: In total, 100 K. pneumoniae isolates were obtained from urine samples, and an antimicrobial susceptibility test was conducted using the disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) instructions. Polymerase chain reaction (PCR) was done for the detection of efflux pump genes including, oqxA, oqxB, and qepA, and their association was statistically analyzed with resistance to antibiotics. Results: The highest rate of resistance was obtained against trimethoprim-sulfamethoxazole (72%), amikacin (70%), levofloxacin (68%), gentamicin (56%), ceftazidime (56%), and ceftriaxone (51%), and the lowest resistance was against imipenem (10%). Thirty one percent of isolates were multidrug resistant (MDR). Molecular distribution test showed that 57% and 56% of isolates carried the oqxA and oqxB genes, respectively. Also, the frequency of qepA genes was 21%. The presence of oqxA/oqxB and qepA efflux genes were significantly associated with fluoroquinolone and beta-lactam resistance phenotypes (P < 0.05). Conclusions: The high frequency of efflux genes showed that this resistance mechanism is the main way, along with other resistance mechanisms in K. pneumoniae isolates. It is necessary to adopt appropriate treatment to reduce the incidence of resistance.