FIG. 2.

Distribution of virulence genes within spa-defined CCs among SAB isolates from IDUs (A) and nonaddicts (B). For construction of the phylogenetic tree, several reference strains were included in the BURP clustering (shaded in gray). Virulence genes (SAg genes, agr, eta, etd, mecA, and pvl genes) were determined by multiplex PCR. SAB strains from IDUs and nonaddicts did not differ in their virulence gene patterns. Staphylococcal enterotoxins (SEs) are indicated by single letters (a = sea, etc.). tst, toxic shock syndrome toxin; egc, enterotoxin gene cluster; eta and etd, exfoliative toxins a and d; agr, accessory gene regulator; pvl, Panton-Valentine leukocidin (lukPV). a, patients with infective endocarditis; b, serum analyzed in neutralization assays. n.d., excluded.