Heavy Metals and Carbapenem-Resistant Klebsiella pneumoniae in a River System of Odisha, India: Correlation and Integrated Risk Assessment

The unregulated release of heavy metals and antibiotics into rivers has the potential to significantly impact human health. Infections caused by healthcare-associated pathogen, carbapenem-resistant Klebsiella pneumoniae (CRKP), present a critical challenge to clinical practitioners due to its resistance to last-line antibiotics. In this study, we investigated co-contamination of heavy metals (As, Cd, Cr, Mn, and Pb) and CRKP isolates in water samples from multiple sites along the river receiving wastewater discharge from urban areas of twin-city, Odisha. We used a composite risk scoring framework integrating chemical risks (based on hazard indices (HI) of heavy metals) and biological risks (based on the proportion of CRKP isolates exhibiting multidrug-resistant phenotypes and their multiple antibiotic resistance (MAR) index. Furthermore, Spearman's correlations and redundancy analysis (RDA) were employed to assess the association between heavy metals and antibiotic resistance genes (ARGs). From the total CRKP isolates identified (n = 91), 90.1% and 9.89% exhibited multidrug resistant (MDR) and extensively drug-resistant (XDR) phenotypes, respectively. Sites D2 and C2 were flagged as high-risk sites based on their composite risk scores of 0.735 and 0.699, respectively. Positive correlations were observed between heavy metals and ARGs (bla_OXA-48, bla_TEM, and bla_SHV). The findings raise concern regarding the potential threat of CRKP and heavy metal pollution in river water while also emphasizing the need for integrated assessment to control their release into the environment.