Investigating the prevalence of beta-lactamase CTX-M resistance gene, its polymorphism and sequencing in Escherichia coli bacteria isolated from urinary infection samples collected from Tabriz hospitals.

BACKGROUND AND OBJECTIVES One of the most common bacteria in the Enterobacteriaceae family is Escherichia coli, which causes urinary tract infections (UTI). UTI is one of the most common bacterial infections. Since E.coli is constantly exposed to antibiotics, antibiotic resistance has increased in this bacterium. From two decades ago, E.coli isolates producing CTX-M have been reported in the community and hospital environments from all over the world. The aim of this study was to determine the prevalence of bla CTX-M resistance gene and its subtypes in E.coli clinical isolates in Tabriz city.MATERIALS AND METHODS In this cross-sectional study, ۲۰۰ clinical samples were collected and verified from the educational hospitals of Tabriz during a period of ۶ months from April ۲۰۱۹ to October ۲۰۱۹. Antibiotic sensitivity test was done by disk diffusion method and the confirmatory test was done by combined disk method to identify ESBL producing strains. DNA of ESBL producing isolates was extracted and the PCR test was performed for the CTX-M gene. Using the RFLP method, CTX-M groups were identified and ۱۰ isolates were randomly selected and sequenced.RESULTS AND DISCUSSION In this study, ۹۰ isolates (۴۵%) were ESBL producing isolates. Among the positive phenotype isolates, ۹۲.۲۲% had the CTX-M gene, of which ۸۵.۱۸% were CTX-M۱. The sequenced isolates were more than ۹۶% identical to CTX-M۱۵. CONCLUSION The prevalence rate of CTX-M in Tabriz is high and the predominant group is CTX-M۱, which requires quick and appropriate measures to prevent it.

کلیدواژه ها:

Escherichia coli ، UTI ، ESBL ، CTX-M ، Tabriz