Background: The rise of β-lactam-resistant Escherichia coli strains presents a major worldwide health issue, especially in clinical environments. Resistance is frequently facilitated by the generation of βlactamase enzymes, which are encoded by particular genetic factors. Objective: This study aims to identify of β-lactamase in E. coli that confer resistance to β-lactam antibiotics. Methods: Beta-lactamase enzymes include ESBLs, MBLs and AmpC were detected by phenotypic methods, and the most prevalent related genes among E. coli isolates were identified by PCR. Results: In total, 305 clinical samples were gathered from patients with gastrointestinal infections, urinary tract infections (UTIs), bloodstream infections, wounds and burns, and respiratory tract infections. Using both traditional testing methods and the VITEK 2 system, fifty isolates of E. coli were verified. Testing for susceptibility to antibiotics showed that the highest resistance rates were against penicillin (94%) and cefoxitin (84%), while meropenem had the lowest rate of resistance (18%). Phenotypic and molecular analyses of beta-lactamase enzymes were conducted on 24 isolates selected according to the antibiotic susceptibility results. The phenotypic results indicated the presences of ESBLs, MBLs and AmpC were 29%, 45% and 45% respectively. According to molecular analysis, the most commonly found resistance genes were blaTEM (100%), followed by blaCTX-M (95%), blaVIM (91%), blaSHV (79%), blaNDM (66%), and blaOXA-48 (37.5%). Conclusion: The study revealed a high prevalence of beta-lactam resistance among Escherichia coli isolates collected from clinical samples in Baghdad. Both phenotypic and molecular investigations validated the extensive occurrence of beta-lactamase enzymes, especially blaTEM and blaCTX-M genes, which are crucial in the resistance. The presence of multiple resistance genes at the same time underlines how complicated the mechanisms of beta-lactam resistance. These findings underscore the urgent need for continuous surveillance, strict infection control policies, and the rational use of antibiotics to limit the spread of resistant E. coli strains in healthcare settings.
jeld et al. (2025) studied this question.