Prevalence of blaOXA-10, blaCTX-M-3 and SHV Genes among ESBL-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Clinical samples in Basra city, Iraq

The current study was conducted to determine the prevalence of extended-spectrum β-lactamase (ESBL) in 78 drug-resistant clinical isolates (25 Klebsiella pneumoniae and 53 Escherichia coli strains) using phenotypic and molecular methods. The phenotypic method was performed using a double-disk synergy test (DDST), while the genotypic method screened for the blaSHV, blaCTX-M13U, and blaOXA-10 genes using specific primers. The phenotypic results showed that out of 53 tested strains of E. coli, 17 (32.07%) produced ESBL. Similarly, out of 25 tested strains of K. pneumoniae, 8 (32%) produced ESBL. Genotypic detection showed that in E. coli, the most abundant gene was SHV, present in 24 strains (45.28%), followed by blaOXA-10 in 23 strains (43.39%) and CTX-M-3 in 8 strains (15.09%). In K. pneumoniae, SHV was detected in 12 strains (48%), followed by OXA-10 and CTX-M-3, each found in 5 strains (20%).