Dissemination of hypervirulent carbapenem-resistant Klebsiella pneumoniae in wastewater.

Abstract

Klebsiella pneumoniae is a Gram-negative bacterium, which can cause a range of difficult-to-treat infections, like; wound infections, urinary tract infections (UTIs), pneumonia, and other diseases. Recent studies have shown that hypervirulent carbapenem-resistant K. pneumoniae (hv-CRKp) is a single, widespread "super-pathogen" that combines significant clinical complications. This convergence is not exclusive to hospitals, as plasmid-mediated virulence and resistance gene exchange occurs in wastewater and other aquatic habitats. Hospital effluents serve as the main hotspot for CRKp discharge, with substantial clonal spread, according to research from regional wastewater networks. Selective pressures from heavy metals, disinfectants, and antibiotic residues speed up horizontal gene transfer in these intricate microbial communities, encouraging the establishment of hv-CRKp. The molecular mechanisms underlying plasmid fusion and mobility, the role of the wastewater resistome and biofilms as sites of genetic exchange, and the One-Health implications of environmental dissemination are all summarized in this assessment of recent investigations from 2023 to 2025. We show how wastewater-based epidemiology may be utilized as an early warning system to discover novel hv-CRKp lineages by merging data from plasmidomics, metagenomics, and global surveillance. The ecological and molecular continuity that links hospitals, wastewater, and the larger environment must be understood when designing next-generation antimicrobial resistance control initiatives against hv-CRKp. This study concludes by discussing research gaps and intervention ideas to reduce environmental spread.