title: Genotyping of vancomycin resistant enterococci in arak hospitals.
abstract: BACKGROUND
  Enterococcal species have emerged as important pathogens in Iran as well as throughout the world. With the increased use of vancomycin, Vancomycin-Resistant Enterococci (VRE) has become an important nosocomial pathogen.
  
  
  OBJECTIVE
  The aim of the present study was to determine the incidence and antimicrobial susceptibility pattern of VRE and also to determine the most important genes that cause resistance to vancomycin in clinical samples in Arak, Iran.
  
  
  METHODS
  In total, 200 enterococci samples were collected from clinical specimens of Arak hospitals. Enterococcal species were identified using standard biochemical tests. Antibiotic susceptibility was tested by the Clinical and Laboratory Standards Institute (CLSI) disk diffusion. Minimum Inhibitory Concentration (MICs) was determined by broth micro dilution. All of the VRE isolates were examined by PCR to detect the presence of VRE genes.
  
  
  RESULTS
  Disk diffusion agar showed that 96 strains (48%) were resistant to gentamicin, 89 (44.5%) to ciprofloxacin, 127 (63.5%) to erythromycin, 142 (71%) to tetracycline, 11 (5.5%) to teicoplanin, 32 (16%) to vancomycin, none to linezolid and 96 (48%) to co-trimoxazole. The MICs of the resistant isolates were as follows; 88 strains had MIC ≥ 32 μg/mL to vancomycin and 59 strains had MIC ≥ 32 μg/mL to teicoplanin. Molecular studies revealed that 59.09% of VRE contained VanA genes and 7.95% of VRE contained the VanB genes. None of the strains had vanC1 and vanC2/3 gene.
  
  
  CONCLUSIONS
  According to the results of this study, rates of vancomycin-resistance in enterococci, in Iran like other parts of the world, is increasing. Therefore accurate methods are required for identifying strains that possess resistance genes because many cases of hospital infections are caused by these strains.
authors.affiliation: Department of Microbiology, Qom Branch, Islamic Azad University, Qom, IR Iran.
authors.forename: Adeleh
authors.initials: A
authors.lastname: Hoseini Zadeh
authors.affiliation: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, IR Iran.
authors.forename: Mana
authors.initials: M
authors.lastname: Shojapour
authors.affiliation: Department of Microbiology, Qom Branch, Islamic Azad University, Qom, IR Iran.
authors.forename: Raziyeh
authors.initials: R
authors.lastname: Nazari
authors.affiliation: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, IR Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Akbari
authors.affiliation: Department of Infectious Diseases, Arak University of Medical Sciences, Arak, IR Iran.
authors.forename: Masumeh
authors.initials: M
authors.lastname: Sofian
authors.affiliation: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, IR Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Abtahi
keywords: VanB protein; Vancomycin; Vancomycin-Resistant Enterococci