Phenotypic and molecular characterization of extended-spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae isolates from communities in South Western Uganda

Abstract

Escherichia coli and Klebsiella pneumoniae are common Extended-spectrum β-Lactamase (ESBL) producing bacteria that can potentially cause substantial challenges in both human and veterinary medicine. This study aimed to characterize the phenotypic and genotypic ESBL production in E. coli and K. pneumoniae isolates from community samples obtained from South Western Uganda. We conducted a cross-sectional study using laboratory methods among stored E. coli and K. pneumoniae isolates. Phenotypic detection of ESBL production was performed using double disk synergy test and the combination disk test, using the Kirby-Bauer disk diffusion method. DNA Polymerase Chain Reaction (PCR) was performed using a conventional PCR thermocycler to detect the ESBL genes. Descriptive statistics were used to summarize the resistance patterns between E. coli and K. pneumoniae. Among the 136 isolates retrieved 96(70.59%) were E. coli. The prevalence of ESBL production among isolates was 37.50% (95% CI = 29.58-46.52). Among E. coli, majority carried blaCTX-M (61.46%) and blaTEM (56.25%) genes. Among K. pneumoniae isolates, there was a uniform distribution of the multiplex genes for blaCTX-M (37.5%), blaOXA (32.5%), blaTEM (30%) and SHV (30%). The blaCTX-M and blaTEM genes were identified as the predominant ESBL genes especially among E. coli isolates which aligns with global trends.