Identification of Extended-Spectrum β-Lactamase Genes and AmpC-β-Lactamase in Clinical Isolates of Escherichia coli Recovered from Patients with Urinary Tract Infections in Kerman, Iran

Escherichia coli is the main causative pathogen in urinary tract infections (UTIs). Antibiotic resistance in this bacterium is an important problem in public health.
The aim of this study was to identify the blaTEM, blaSHV, blaOXA, and blaPER genes and AmpC-β-lactamase in clinical isolates of E. coli recovered from patients with UTIs in Kerman, Iran.
E. coli isolates (N = 105) were analyzed for their antibiotic susceptibility with the disk diffusion method. ESBL and AmpC-producing isolates were detected using phenotypic methods. PCR was used to identify the blaTEM, blaSHV, blaOXA and blaPER genes in ESBL and AmpC-positive isolates.
More than 50% of the isolates were multi-drug resistant. The prevalence of ESBLs, AmpC-β-lactamase, blaTEM and blaOXA in the inpatient isolates was 37.2%, 2%, 37.2% and 5.8%, respectively. Further, the prevalence of ESBLs, blaTEM, blaSHV and blaOXA in the outpatient isolates was 42.5%, 24%, 5.5% and 1.8%, respectively.
The prevalence of ESBL-producing E. coli strains in the community (outpatients) is higher than that in inpatients in Kerman, Iran. An outbreak of ESBL-producing isolates in the community can be a serious problem for public health, as resistance to other classes of antibiotics such as aminoglycoside and fluoroquinolones is often related with ESBL and AmpC production, therefore, detection of ESBL and AmpC-producing isolates in the community and hospitals is very important for the treatment and prevention of such isolates.