Occurrence of blaNDM-1 and blaNDM-5 in a Tertiary Referral Hospital of North India.

Abstract

Antimicrobial resistance poses a great challenge to clinicians leaving very limited treatment options available. A panel of carbapenem-resistant bacterial isolates was selected based on Rapidec Carba NP test from a total of 900 samples, which were collected from different specialities hospitals of Kanpur, India. Carba NP-positive isolates were screened for carbapenemases, extended-spectrum beta-lactamases (ESBLs), quinolone resistance, and 16s methyltransferase genes. Presence of diverse blaNDM (blaNDM-1 and blaNDM-5) were detected and horizontal transferability was determined by transformation and conjugation assay. Elimination of blaNDM-1 and blaNDM-5 harboring plasmid was done by treating the isolates with sodium dodecyl sulfate. The transcriptional response of blaNDM-1 and blaNDM-5 under the exposure of imipenem, meropenem, and ertapenem stress was determined by quantitative real-time polymerase chain reaction. blaNDM harboring isolates were found to be horizontally transferable through IncFrepB and K type plasmid and could be successfully eliminated after the single treatment with sodium dodecyl sulfate. A distinct pattern of transcriptional response was observed for blaNDM-1 and blaNDM-5 under the pressure of carbapenem antibiotics where an upregulated expression of both blaNDM-1 and blaNDM-5 was observed. Minimum inhibitory concentration (MIC) results revealed that blaNDM harboring strains showed a high MIC range against imipenem, meropenem, ertapenem, cefepime, and aztreonam. Thus, prudent action should be taken to control the spread of these multidrug-resistant determinants or at least slowing down their lateral transfer in the hospital settings.