title: Prevalence and antimicrobial resistance pattern of methicillin resistant Staphylococcus aureus (MRSA) strains isolated from clinical specimens in Ardabil, Iran.
abstract: OBJECTIVE
  Reports on MRSA strains are increasing worldwide. The aim of this study was to find the prevalence of MRSA strains isolated from clinical specimens and to evaluate their resistance profile. Additionally we compared the phenotypic and genotypic methods for detection of methicillin resistance.
  
  
  METHODS
  In this cross-sectional study, a total of 41 isolates of S. aureus were collected from clinical specimens at two teaching hospitals in Ardabil, Iran. All isolates were identified at the species level by standard biochemical tests. The methicillin resistance were evaluated using three methods: PCR for mecA gene, agar dilution for determination of oxacillin MIC and disk diffusion test to detect methicillin, oxacillin and cefoxitin resistance. Antimicrobial resistance patterns were determined by disk diffusion method.
  
  
  RESULTS
  The results identified 19 (46.3%) out of 41 isolates as MRSA. Most of the MRSA strains (68.4%) were isolated from patients hospitalized in ICU. All isolates were susceptible to vancomycin, mupirocin and linezolid. Among other antibiotics co-trimoxazole was more active against MRSA isolates. Using PCR as reference method all the phenotypic tests showed 100% specificity. The sensitivity for MIC test and cefoxitin was 100% and for methicillin and oxacillin disks was 77.7% and 89.5%, respectively.
  
  
  CONCLUSIONS
  The prevalence of MRSA strains in our hospitals especially in ICU ward was high and disk diffusion testing using cefoxitin or oxacillin MIC test as an alternative to PCR for detection of MRSA is recommended.
authors: Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran.
authors: Solmaz
authors: S
authors: Dibah
authors: Department of Microbiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran.
authors: Mohsen
authors: M
authors: Arzanlou
authors: Young Researchers Club, Ardabil Branch, Islamic Azad University, Ardabil, Iran.
authors: Elham
authors: E
authors: Jannati
authors: Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran.
authors: Reza
authors: R
authors: Shapouri
keywords: Antibiotic resistance; Methicillin resistance; Staphylococcus aureus