title: Prevalence of Class D Carbapenemases among Extended-Spectrum β-Lactamases Producing Escherichia coli Isolates from Educational Hospitals in Shahrekord.
abstract: BACKGROUND
  Extended-spectrum β-lactamases (ESBLs) are a set of plasmid-borne, various and quickly evolving enzymes that are a main therapeutic issue now-a-days for inpatient and outpatient treatment.
  
  
  OBJECTIVE
  The aim of this study was to determine multi-drug resistance (MDR) and ESBLs producing E. coli strains, prevalence of class D Carbapenemases among ESBLs producing Escherichia coli isolates from educational hospitals in Shahrekord, Iran.
  
  
  METHODS
  Uropathogenic Escherichia coli strains were isolated from patients with Urinary Tract Infections (UTIs). The agar disc diffusion test was used to characterize the antimicrobial sensitivity of the E. coli isolates. The ESBL positive strains were identified by phenotypic double-disk synergy test, by third-generation cephalosporin in combination with or without clavulanic acid. Multiplex PCR was carried out for detection of the three families of OXA-type carbapenamases including OXA-23, OXA-24, and OXA-48 in E. coli strains.
  
  
  RESULTS
  All bacterial isolates were susceptible to meropenem. Ninety isolates produced ESBL, 55 E. coli isolates from inpatients, and 35 isolates from outpatients, with a significant association (p< 0.05). The prevalence of OXA-23, OXA-24, and OXA-48 in the ESBLs producing isolates was respectively 21%, 18%, and 11% for inpatients, and 10%, 8%, and 6% for outpatients.
  
  
  CONCLUSIONS
  ESBL-producing E. coli isolates are also a major threat in the clinical setting. The findings of this study indicated the high occurrence of ESBLs and multiple antibiotic resistance in E. coli isolates.
authors.affiliation: Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences , Mashhad, IR Iran .
authors.forename: Mohammad-Sadegh
authors.initials: MS
authors.lastname: Damavandi
authors.affiliation: Assistant Professor, Department of Microbiology and Immunology, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences , Shahrekord, Iran .
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Gholipour
authors.affiliation: Student, Department of Microbiology and Immunology, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences , Shahrekord, Iran .
authors.forename: Mohammad
authors.initials: M
authors.lastname: Latif Pour
keywords: Bacterial resistance; Multiplex polymerase chain reaction; Urinary tract infections