Molecular resistome profiling of multidrug-resistant K. pneumoniae from a tertiary-care hospital in North India.

K. pneumoniae is a major opportunistic pathogen and an important cause of multidrug-resistant gram-negative infections, driven largely by the spread of ESBL and carbapenemase enzymes. Therefore, it is of interest to analyse the phenotypic resistance patterns and molecular resistome of 100 non-duplicate clinical isolates collected from a tertiary care hospital in North India using CLSI- guided susceptibility testing, mCIM/eCIM assays and PCR detection of resistance genes. Overall, 51% of isolates were MDR, with high resistance to cephalosporins, fluoroquinolones and penicillins and the highest carbapenem resistance was observed for ertapenem (57%). Carbapenem- resistant isolates comprised 40%, of which 70% produced metallo-β-lactamases and 10% serine β-lactamases, while ESBL genes (blaCTX-M-1 54%, blaSHV 50%, blaTEM 28%) and carbapenemases (blaNDM 22%, blaOXA-48 23%) were frequently detected, including ESBL-carbapenemase co-harbouring in 35% and a "super-resistome" in 2%. Thus, we show the urgent need for sustained molecular surveillance, strict infection control and strengthened antimicrobial stewardship to curb the dissemination of highly resistant K. pneumoniae.