Detection of Plasmid-Mediated Quinolone Resistance Genes in Clinical and Environmental Hospital Isolates of Klebsiella pneumoniae in Al-Najaf City pneumoniae Klebsiella


Aim of study : This study aimed to detected the presence of the plasmid mediated quinolone resistance genes in quinolone resistant Klebsiella pneumoniae isolates from clinical and environmental hospital samples.Methodology : A total of 195 clinical samples of different sources and 50 environmental hospital samples were collected from three main hospitals in Al-Najaf city .K. pneumoniae was identified depending on cultural and traditional biochemical tests, then confirmed by API 20E system. Phenotype detecting of quinolone resistance in K. pneumoniae isolates were carried out by growing on MacConkey agar supplemented with 10µg/ml Ciprofloxacin. Antibiotic susceptibility performed by disk diffusion. Quinolones resistant isolates were selected for molecular study for detecting aac (6 ')-Ib-cr, qepA, qnrS and qnrB as plasmid mediated resistance genes using Multiplex polymerase chain reaction.Results: Eighty-nine isolates were identified as .K.pneumoniae.Thirty–four(38%) resist ciprofloxacin(10µg/ml ) and were resistant to at least fourteen antibiotics to which they are tested. Hence, all isolates were considered to be multidrug resistant (MDR). The results of detection the plasmod mediated antibiotic resistance genes revealed the widely distribution aac (6 ')-Ib-cr gene alone or combined with qnrS gene in 14 (41.18%) isolates ,or with qepA (2.94%) and 8.82% of bacterial isolates carried aac (6 ')-Ib-cr, qepA and qnrS whereas only one isolates (29.41%) that caused wound infection showed the presence of qnrB gene.Conclusions :High prevalence MDR K. pneumoniae harbouring PMQR mediated by aac(6`)-Ib-cr and qnrS . This study is the first trail to detect PMQR genes in clinical and environmental isolates of K.pneumoniae in Iraq. Recommendations:Further studies are necessary to understand the dissemination of plasmid mediated genes (qnr, aac(6`)-Ib-cr and qepA gene) and chromosomal resistance among K.pneumoniae and other common pathogenic bacteria.