pKpQIL-like plasmid contributes to the dissemination of blaNDM-1 and plasmid mediated quinolone resistance determinants among multi drug resistant Klebsiella pneumoniae in Assiut university hospital, Egypt.

BACKGROUND AND

OBJECTIVES

Concomitant carriage of blaNDM-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 blaNDM-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 blaNDM-1 and PMQRs were genotyped using pulsed field gel electrophoresis. Horizontal transfer of blaNDM-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 blaNDM-1 and PMQRs. Plasmids carrying blaNDM-1 and PMQRs were typed by PCR based replicon typing.

RESULTS

All MDR K. pneumoniae contained class 1 integron and belonged to 15 pulsotypes. BlaNDM-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 blaNDM-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 blaNDM-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.