Nasal colonization of SCCmec II, III and tst-1 positive Methiticillin resistance Staphylococcal aureus isolated from patients in a hemodialysis unit, Tehran, Iran

Infections due to Staphylococcus aureus account for a major cause of morbidity and mortality in hemodialysis patients.1,2 Colonization of S.aureus is associated with a four-fold higher risk of bloodstream infection. Hemodialysis patients suffer from a high rate of infection or colonization with MRSA which lead to increased rate of mortality, length of hospital stay, and healthcare costs compared to those infected with methicillin-susceptible S. aureus.3,4 Methicillin susceptible S.aureus changes to MRSA by acquisition of staphylococcal Cassette Chromosome mec (SCCmec) a genomic island that encodes methicillin resistance.5 The tst gene, a mobile genetic element, encodes Toxic shock syndrome toxin 1 (TSST-1) a superantigenic toxin secreted by both MRSA and MSSA.6 Besides, Panton-Valentine leukocidin is a gamma-toxin mostly produced by CA-MRSA.7 The aim was to determine the presence of mecA, lukS/lukF-PV (PVL), eta & etb genes (exfoliative toxin A & B) and tst genes (TSST-1) in two S.aureus colonized patients.