title: Emergence of SCCmec Type I Obtained From Clinical Samples in Shiraz Teaching Hospitals, South-West of Iran.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of nosocomial infections. Methicillin resistance in S. aureus is caused by the acquisition of the mecA gene, located on a mobile genetic element called the staphylococcal cassette chromosome (SCC).
  
  
  OBJECTIVE
  The aim of this study was to evaluate the presence of the predominant SCCmec type present among clinical isolates.
  
  
  METHODS
  This cross-sectional study was performed on a total of 146 MRSA isolates obtained from clinical specimens between 2012 and 2013 from two major hospitals in Shiraz, Southwest of Iran. Antibiotic susceptibility profiles were determined by the disc diffusion method according to the guidelines of The Clinical and Laboratory Standards Institute. Bacterial DNA was extracted using the small-scale phenol-chloroform extraction method and was employed as polymerase chain reaction (PCR) templates for the assigned current SCCmec types.
  
  
  RESULTS
  The assigned SCCmec types by PCR revealed the SCCmec type I as the predominant type with 86 (58.9%) samples, followed by the SCCmec type II with 29 (19.9%), type III with 16 (11.0%), and type IV with 12 (8.2%) samples, respectively. The SCCmec type I MRSA isolates were significantly recovered from blood (80%) and sputum (67.2%). The results of antibacterial susceptibility tests for the MRSA isolates showed that all of those carrying the SCCmec type I and II had significantly greater resistance rates to Gentamicin and Rifampin than the isolates containing the SCCmec type III. Also, a significant difference was detected for susceptibility to Co-trimoxazole between the SCCmec type I and II MRSA isolates and the SCCmec type III, which was more resistant.
  
  
  CONCLUSIONS
  The frequency of the isolates containing type I in the current study can indicate an emergence of this SCCmec type in the studied medical centers.
authors: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Hadi Sedigh
authors: HS
authors: Ebrahim-Saraie
authors: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran ; Shiraz HIV/AIDS Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Mohammad
authors: M
authors: Motamedifar
authors: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Jamal
authors: J
authors: Sarvari
authors: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Seyedeh Mahsan
authors: SM
authors: Hoseini Alfatemi
keywords: Antimicrobial Susceptibility; Methicillin-Resistant Staphylococcus aureus (MRSA); Mobile Genetic Elements