Abstract
BACKGROUND AND OBJECTIVES: Concomitant carriage of bla(NDM-1) and plasmid mediated quinolone resistance determinants (PMQRs) by multi drug resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) has increased globally, often related to their presence on transmissible plasmids. In this study, we hypothesized the presence of bla(NDM-1) and PMQRs on a single conjugative plasmid that circulates among K. pneumoniae strains isolated from Assiut University Hospital. MATERIALS AND METHODS: Twenty-two clinical MDR K. pneumoniae strains harboring both bla(NDM-1) and PMQRs were genotyped using pulsed field gel electrophoresis. Horizontal transfer of bla(NDM-1) and PMQRs was evaluated by conjugation and trans-conjugants were screened for the presence of both genes and integron by PCR. Trans-conjugant's plasmid DNA bands were purified using agarose gel electrophoresis and different DNA bands were screened for bla(NDM-1) and PMQRs. Plasmids carrying bla(NDM-1) and PMQRs were typed by PCR based replicon typing. RESULTS: All MDR K. pneumoniae contained class 1 integron and belonged to 15 pulsotypes. Bla(NDM-1) and PMQRs were co-transferred in each conjugation process. Multiple replicons (5-9 types) were detected in each trans-conjugant; with IncFIIK and IncFIB-KQ replicons being common among all trans-conjugants. Both bla(NDM-1) and PMQRs were detected on a pKpQIL-like multi-replicon plasmid that was present in all K. pneumoniae strains. CONCLUSION: In view of these results, the presence of bla(NDM-1) and PMQRs on pKpQIL-like plasmid that existed in multiple unrelated K. pneumoniae isolates is highly suggestive of the circulation of pKpQIL-like MDR plasmids in our hospitals. Moreover, carriage of integrons by the-circulating MDR plasmids increases the risk of dissemination of antimicrobial resistance among pathogens.