Background

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae represent a major cause of antimicrobial resistance, particularly in hospital settings.

Methods

This laboratory-based observational study included 385 non-duplicate isolates of Escherichia coli and Klebsiella pneumoniae from hospitalized patients over one year. Identification was performed using standard biochemical tests. ESBL screening and phenotypic confirmation were carried out using disc diffusion and combined disc tests according to CLSI M100 (2023) guidelines. Antibiotic susceptibility testing was performed using the Kirby–Bauer disc diffusion method.

Results

Of 385 isolates, E. coli accounted for 68% and K. pneumoniae for 32%. ESBL production was confirmed in 158 isolates (41.04%), with a higher prevalence in E. coli (50%) than K. pneumoniae (21.95%). ESBL producers exhibited markedly higher resistance to third-generation cephalosporins and fluoroquinolones, while susceptibility to piperacillin–tazobactam and carbapenems remained higher.

Conclusion

A considerable prevalence of ESBL-producing isolates among hospitalized patients highlights the need for routine ESBL detection and antimicrobial stewardship to limit resistance spread.