title: Virulence Factors of Staphylococcus aureus Isolates in an Iranian Referral Children's Hospital.
abstract: OBJECTIVE
  The clinical importance of Staphylococcus aureus (S. aureus) is attributed to notable virulence factors, surface proteins, toxins, and enzymes as well as the rapid development of drug resistance. The aim of this study was to compare the occurrence of virulence factors produced by S. aureus strains isolated from children in an Iranian referral children's hospital.
  
  
  METHODS
  The presence of genes encoding for the enterotoxins A (sea), B (seb), C (sec), D (sed), TSST-1 (tsst), exfoliative toxin A (eta), and exfoliative toxin B (etb) were detected by Multiplex polymerase chain reaction (PCR) using specific primers. In addition, the standardized Kirby-Bauer disc-diffusion method was performed on Mueller-Hinton agar.
  
  
  RESULTS
  In total, 133 S. aureus isolates were obtained from different patients. Of these S. aureus isolates, 64 (48%) were methicillin-resistant S. aureus (MRSA), and all of these tested positive for the mecA gene. Regarding the classical enterotoxin genes, sea gene (40.6%) was the most prevalent followed by seb (19.6%), tsst (12.8%), eta (11.3%), etb (9%), sed (4.5%), and sec (3%). Among methicillin-susceptible S. aureus (MSSA) isolates, seb and tsst were the more prevalent toxins in comparison with MRSA isolates (p < 0.05), while the frequency of sea, sed, eta, and etb genes were higher among MRSA isolates (p > 0.05).
  
  
  CONCLUSIONS
  In our study enterotoxin A was produced by 40.6% of the isolates (48% from MRSA and 33% from MSSA isolates) which was higher than in previous reports. According to our results, strict hygiene and preventative measures during food processing are highly recommended.
authors: Department of Infectious Disease, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Farah
authors: F
authors: Sabouni
authors: Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Shima
authors: S
authors: Mahmoudi
authors: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Abbas
authors: A
authors: Bahador
authors: Department of Infectious Disease, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Babak
authors: B
authors: Pourakbari
authors: Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Reihaneh Hosseinpour
authors: RH
authors: Sadeghi
authors: Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mohammad Taghi Haghi
authors: MT
authors: Ashtiani
authors: Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Bahram
authors: B
authors: Nikmanesh
authors: Department of Infectious Disease, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran ; Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Setareh
authors: S
authors: Mamishi
keywords: Staphylococcus aureus; enterotoxins; exfoliative toxins; toxin of toxic shock syndrome-1