Shima Mirzaei Parsa - ۱Department of Microbiology, Kerman Branch, Islamic Azad University, Kerman, Iran
Mohammad Javad Soltani Banavandi - Department of Microbiology, Kerman Branch, Islamic Azad University, Kerman, Iran
Mohammad Hassan Shahhosseiny - Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran- Iranian Gene Fanavar Institute, Tehran, Iran

Background: Nosocomial infection caused by antibiotic resistance bacteria is increasing in the world. Resistance to extendedspectrumbeta-lactamase (ESBLs) is one of the most important antibiotic resistance mechanisms.Objectives: According to prevalence of E. coli producing ESBL, the aim of this study was to identify the blaCTX and blaSHV genes,which are the causing genes of the resistance to beta-lactam antibiotics by Multiplex-PCR method.Methods: A total of ۱۰۰ isolates of E. coli were collected from the Milad Hospital in Tehran. Disk diffusion method was done and ESBLpositive isolates were determined by combination disc test. DNA extraction of them was carried out and the presence of blaCTX andblaSHV genes was evaluated by using the M-PCR method.Results: By using the molecular method on all isolates, ۴۶ of them were positive for the CTX gene, three isolates were positive forthe SHV gene, and none of the isolates have both blaCTX and blaSHV genes. Antibiogram test was done on all samples in which ۱۷ ofthem were resistant to antibiotics.Conclusions: Based on the goals of this study for investigation of frequency of SHV and CTX antibiotic resistance genes in collectedisolates in order to improve PCR detection method, achieved results emphasized that the M-PCR method, with high accuracy andsensitivity, should be used as the substitution of phenotype tests in clinical laboratories. In addition, avoiding the indiscriminateprescribing of antibiotics is an important necessity.

Escherichia coli, ESBL, blaCTX, blaSHV, PCR