First report of QNRA isolated from extended spectrum B-lactamase producing hospital-acquired Klebsiella pheumoniae in Kuwait

Abstract

Introduction/objectives: Extended Spectrum beta-lactamase (ESBL)- mediated resistant Klebsiella pneumoniae are important opportunistic pathogens. In this study we investigated the prevalence of plasmidmediated fluoroquinolone resistance in ESBL-producing K. pneumoniae in nosocomial infections in Kuwait. Methods: From a total of 72 non-duplicate quinolone and cephalosporin resistant Enterobacteriacae obtained from October-December 2010 from Ahmadi hospital in Kuwait, 16 were K. pneumoniae. Antimicrobial susceptibility was determined by Vitek, Microscan, double disc diffusion, agar dilution and E-test against a panel of 26 antimicrobial agents. The presence of blaSHV, blaTEM, blaCTX-M, gyrA, parC, qnrA, qnrB, qnrS and class 1 integrons were determined by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) was used for typing the strains and the results were analysed according to Tenover criteria. Results: All 16 isolates were resistant to all antibiotics tested including ciproflaxoacin (MIC>4), tazobactam (MIC>16), cefotaxime (MIC>16) and ceftazidime (MIC>16); except for carbapenems, amikacin, and tigecycline. blaTEM, blaSHV&blaCTX-M-15 were present in 81.25% (13), 81.25% (13) and 68.75% (11) respectively. Nine (56.25%) isolates contained all three bla genes of which one harboured qnrA (A2 allele) and a class 1 integron. No mutations were found in gyrA and parC. PFGE revealed that K. pneumoniae isolates harbouring ESBL genes consisted of two distinct clones. Conclusion: Contrary to a previous study, we hereby report the emergence of plasmid-mediated qnrA gene among ESBL producing nosocomial K. pneumoniae for the first time in Kuwait. Identification of these strains are crucial for administering the correct antibiotic and preventing their spread among hospitalised patients.