title: Detection of Methicillin Resistance and Various Virulence Factors in Staphylococcus aureus Strains Isolated from Nasal Carriers.
abstract: BACKGROUND
  Staphylococus aureus can be found as a commensal on skin and nasal flora or it may cause local and invasive infections. S. aureus has a large number of virulence factors.
  
  
  OBJECTIVE
  To investigate the methicillin resistance and frequency of various virulence factors in S. aureus nasal isolates.
  
  
  METHODS
  Descriptive study.
  
  
  METHODS
  Nasal samples collected from university students were cultured in media. S. aureus was identified by conventional methods and the Staphyloslide latex test (Becton Dickinson, Sparks, USA). Antibiotic susceptibility tests were conducted, and the methicillin resistance was determined. The mecA, nuc, pvl and staphylococcal toxin genes were examined by polymerase chain reaction (PCR).
  
  
  RESULTS
  S. aureus was isolated in 104 of 600 (17.3%) nasal samples. In total, 101 (97.1%) S. aureus isolates were methicillin-sensitive and the remaining 3 (2.9%) were methicillin-resistant. Furthermore, all but five isolates carried at least one staphylococcal enterotoxin gene, with seg being predominant. The tst and eta genes were determined in 29 (27.9%), and 3 (2.9%) isolates, respectively. None of the S. aureus isolates harbored see, etb, and pvl genes.
  
  
  CONCLUSIONS
  A moderate rate of S. aureus carriage and low frequency of MRSA were detected in healthy students. S. aureus isolates had a high prevalence of staphylococcal enterotoxin genes and the tst gene. In this study, a large number of virulence factors were examined in S. aureus nasal isolates, and the data obtained from this study can be used for monitoring the prevalence of virulence genes in S. aureus strains isolated from nasal carriers.
authors.affiliation: Department of Microbiology, Selçuk University Faculty of Medicine, Konya, Turkey.
authors.forename: Hatice Türk
authors.initials: HT
authors.lastname: Dağı
authors.affiliation: Department of Microbiology, Selçuk University Faculty of Medicine, Konya, Turkey.
authors.forename: Duygu
authors.initials: D
authors.lastname: Fındık
authors.affiliation: Department of Microbiology, Selçuk University Faculty of Medicine, Konya, Turkey.
authors.forename: Gamze
authors.initials: G
authors.lastname: Demirel
authors.affiliation: Department of Microbiology, Selçuk University Faculty of Medicine, Konya, Turkey.
authors.forename: Uğur
authors.initials: U
authors.lastname: Arslan
keywords: Methicillin resistance; Staphylococcus aureus; virulence factors