Clinically significant Klebsiella pneumoniae persistence in wastewater: co-occurrence of virulence and multidrug resistance genes

BACKGROUND: Wastewater monitoring is an effective approach for assessing public health, providing insight into circulating pathogens and their associated antimicrobial resistance genes. Klebsiella pneumoniae, a clinically and environmentally significant opportunistic pathogen, was investigated in this study. METHODS: 120 wastewater samples were collected from various sources, and the isolates were analyzed for antimicrobial susceptibility using the Kirby-Bauer disk diffusion method against 11 antibiotics, in addition to PCR-based detection of β-lactamase and virulence genes. RESULTS: (22.5%) was the most common carbapenemase gene. Almost all isolates (98.8%) possessed at least one virulence gene, with mrkD (96.3%) and entB (79.0%) being the most detected. Additionally, 86.5% of the isolates carried two or more virulence genes. Notably, no hypervirulent strains were observed. CONCLUSION: Overall, wastewater from diverse sources constitutes a significant reservoir of multidrug-resistant and virulent K. pneumoniae strains. Their environmental release poses a considerable public health risk, highlighting the urgent need for improved wastewater management and continuous microbial surveillance.