PLASMID-MEDIATED QUINOLONE RESISTANCE GENES IN ESBL PRODUCING KLEBSIELLA PNEUMONIAE ISOLATED FROM URINARY TRACT INFECTIONS IN TEHRAN HOSPITALS

Background and Aim:Recent studies have shown that the increasing prevalence of plasmid-mediated quinolone resistance (PMQR) in Klebsiella pneumoniae isolates, worldwide. The aim of this study was to investigate the prevalence of PMQR and blaCTX-M genes determinants among the K. pneumoniae isolates in patients with urinary tract infection (UTI) and their clonal relatedness in Tehran, Iran.Methods:A total of 70 K. pneumoniae isolates were recovered from urine samples. Antimicrobial susceptibility testing and minimum inhibitory concentrations (MICs) were determined. Also, ESBLs production was screened. The presence of qnrA, qnrB, qnrS and blaCTX-M genes were determined by PCR. Conjugation experiments and PCR-based replicon typing was used to identify plasmid replicons. Also, the clonal relatedness of isolates was evaluated by random amplified polymorphic DNA (RAPD) typing.Results:The resistance rate to antibiotics especially fluoroquinolones among the isolates was high. 75.7% (53/70) of isolates were ESBLs positive. The rate of qnrB, qnrS and blaCTX-M genes were 62.9% (44/70), 64.3% (45/70) and 77.1% (54/70), respectively. All isolates were negative for qnrA gene. Analysis of the plasmid profiles showed that there was no relationship between the plasmids and antibiotic resistance. In conjugation experiments, 5 of 8 tested isolates had conjugative plasmids. IncL/M was the most common replicon type (94.1%). Also, RAPD-PCR results showed a high heterogeneity.Conclusion:This study showed a high heterogeneity and frequency of PMQR genes among the isolates. The spread of plasmids carrying resistance genes would be resulted in fulminant antimicrobial resistance and treatment failure which are severe concerns recently.

کلیدواژه ها:

Klebsiella pneumoniae ، PMQR ، Plasmid replicon typing ، RAPD-PCR