title: Genetic properties of blaCTX-M and blaPER β-lactamase genes in clinical isolates of Enterobacteriaceae by polymerase chain reaction.
abstract: OBJECTIVE
  blaCTX-M and blaPER are two genes that encode class A extended-spectrum β-lactamases (ESBLs) and can be responsible for therapeutic problems. This study was carried out to evaluate the molecular properties of these genes in clinical isolates of Enterobacteriaceae by polymerase chain reaction (PCR), restriction digestion and sequencing.
  
  
  METHODS
  During six months, starting from January 2012, one hundred clinical isolates of Enterobacteriaceae were collected from urinary samples. The ESBL-producing isolates were detected by phenotypic confirmation test. After plasmid extraction, blaPER and blaCTX-M genes were detected using PCR by specific primers. The blaCTX-M PCR products were digested with Taq1, and two of the blaCTX-M genes were sequenced.
  
  
  RESULTS
  Phenotypic tests showed that 27 (27%) isolates were ESBL producers with the highest frequency for Klebsiella pneumoniae (47.4%) and Escherichia coli (17.9%). Twenty six (26%) of Enterobacteriaceae isolates harbored the blaCTX-M gene, and none of them had blaPER . The restriction analysis of PCR products showed that all blaCTX-M amplified products had the same patterns. Both sequenced bacteria were CTX-M-15 type ESBL carriers.
  
  
  CONCLUSIONS
  The results of this study showed the blaCTX-M-15 gene in Enterobacteriaceae isolates for the first time in Mashhad, Iran. High degrees of associated resistance to co-trimoxazole and gentamicin were found in ESBL producers. Therefore, an integrated and regular management of antibiotic prescription need to be trained in our society.
authors: Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
authors: Mahboobeh Nakhaei
authors: MN
authors: Moghaddam
authors: Department of Biology, Science and Research Branch, Islamic Azad University, Fars, Iran.
authors: Mehrdad Hashemi
authors: MH
authors: Beidokhti
authors: Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Saeid Amel
authors: SA
authors: Jamehdar
authors: Medical Genetic Research Center, School of Medical Science, Mashhad, Iran.
authors: Martha
authors: M
authors: Ghahraman
keywords: CTX-M-15; Enterobacteriaceae; Extended-spectrum beta-lactamase; PER