Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae and its Emerging Patterns of Resistance and Virulence

Carbapenem-resistant Klebsiella pneumoniae (CRKP) posses an urgent public health threat. This study examined antimicrobial resistance, carbapenemase production, and virulence gene profiles in clinical isolates from a tertiary care hospital in southern India. A total of 200 non-duplicate isolates were tested for antimicrobial susceptibility, carbapenemase production using the modified carbapenem inactivation method (mCIM) and extended carbapenem inactivation method (eCIM), and molecular detection of resistance and virulence genes by multiplex PCR. Twenty-seven isolates (13.5%) were identified as carbapenemase producers. The most common resistance determinants were blaOXA- 48-like (85%) and blaNDM (57%), while blaKPC, blaVIM, and blaIMP were not detected. Virulence genes were widespread, including entB (85%), mrkD (77%), magA (70%), ybtS (74%), and iutA (44%). Capsular types K1 and K2 were observed; however, hypervirulent CRKP was not identified. These findings highlight the coexistence of carbapenem resistance and virulence traits in clinical isolates and underscore the importance of molecular surveillance, strict infection-control measures, and the exploration of alternative therapeutics.