Journal of Preventive Medicine & Infectious Diseases

Abstract

The rising occurrence of antimicrobial-resistant Klebsiella pneumoniae represents a significant threat to global public health, especially due to the spread of extended-spectrum β-lactamases (ESBLs) and carbapenemases. This study aimed to characterise the genetic profiles, resistance determinants, and mobile genetic elements (MGEs) of K. pneumoniae isolates from both clinical and environmental sources in Lusaka, Zambia. Using phenotypic antimicrobial susceptibility testing (AST), PCR, and whole genome sequencing (WGS), we found a high prevalence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan-drug resistant (PDR) strains, with resistance genes such as blaCTX-M-15, blaTEM-1B, blaNDM-5, and blaOXA-1 mainly detected in clinical isolates. In environmental isolates, especially from hospital surfaces and water sources, SHV-type β-lactamases were most common, often carried on diverse and variant plasmids such as IncFIB(K) and IncR, aiding resistance gene spread. Genotypic analysis revealed multiple sequence types (ST), notably ST 268 as the dominant clone across clinical and environmental samples, with genetic relatedness indicating ongoing transmission. Resistance determinants, virulence factors, and MGEs showed considerable diversity, driven by horizontal gene transfer mechanisms including transposons, insertion sequences, and integrons. These findings highlight the urgent need for enhanced surveillance, infection control, and antimicrobial stewardship to limit the spread of resistant K. pneumoniae strains within healthcare and community settings in Zambia.