Isolation and molecular characterization of extended-Spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae from hospital environments in Northeastern Bangladesh.

OBJECTIVE: The study aims to investigate the prevalence of extended-spectrum β-lactamase (ESBL) genes (blaCTX-M-1, blaTEM, blaSHV) in Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) isolates recovered from hospital environmental swab samples, including bed surfaces, floors, and waste bins, in Northeastern Bangladesh. METHOD: A total of 54 samples were randomly collected from hospital wards. Isolates were identified using cultural and biochemical tests and tested for β-lactam susceptibility. ESBL and other resistance genes (tetB, gyrA) were detected by molecular analysis. RESULTS: Among 62 phenotypically resistant isolates (39 K. pneumoniae, 23 E. coli), 74% of K. pneumoniae and 91% of E. coli harbored the blaCTX-M-1 gene, 73% and 91% carried the blaTEM gene, and 18% and 5% carried the blaSHV gene, respectively. Additionally, 5% of K. pneumoniae and 27% of E. coli possessed the tetB gene, while 22% and 95% carried the gyrA gene. Phylogenetic analysis confirmed clustering of blaSHV, blaCTX-M-1, and blaTEM genes within their respective families. Multidrug resistance was observed in 90% of isolates, with E. coli at 95% and K. pneumoniae at 87%. Furthermore, 7.5% of K. pneumoniae and 17.4% of E. coli exhibited pan-resistance to seven antibiotic classes. CONCLUSION: The results highlight the urgent need to address the antimicrobial resistance crisis in hospital settings to reduce the risk of nosocomial infections in Bangladesh.