High prevalence of Staphylococcus aureus cultivation and superantigen production in patients with psoriasis

The aim of this study was to evaluate the association of Staphylococcal enterotoxins (se) a through e, exfoliative toxin (et) a and b, toxin and toxic shock syndrome toxin (tst) and mecA with psoriasis. We also investigated the distribution of Staphylococcus aureus (S. aureus) in the skin and nares. Fifty consecutive patients with chronic plaque-type psoriasis and 50 sex- and age-matched healthy controls were included in this study. There was a statistical difference in cultivation of S. aureus between lesional (64%) and non-lesional skin (14%) in patients with psoriasis (p = 0.037). S. aureus was cultivated from the nares in 25 (50%) of 50 patients with psoriasis and in 17 (34%) of 50 healthy controls (p > 0.05). In psoriasis patients, 31 (96.8%) out of the 32 strains isolated from the lesional skin and 3 (42.3%) out of the 7 strains isolated from the non-lesional skin were toxigenic (p = 0.01). Isolated strains from the nares were toxigenic in 96% (24/25) for patients with psoriasis and in 41.2% (7/17) for healthy controls, respectively (p = 0.006). Patients with cultivation-positive in lesional skin had a significantly higher PASI score than patients who were cultivation-negative in lesional skin (8.28 +/- 3.97 vs. 5.89 +/- 2.98, p = 0.031). Our results confirm that S. aureus colonization and its toxigenic-strains are associated with psoriasis. According to our findings, non-classical superantigens such as methicillin resistance gene (mecA), see and etb may also be associated with psoriasis.