At least one of the non-toxigenic strains, DA-108, was derived from a clinical infection not associated with toxic shock syndrome [15], while strain W10 was isolated from a veterinary infection but appears to carry a pCS1-4-like plasmid; i.e. it still carries a pCS1-type plasmid but lacks tcsL. All strains in our study contain other putative virulence factors including the cholesterol-dependent cytolysin sordellilysin (sdl), neuraminidase (nanS), phospholipase C (csp) and collagenase (colA). Here, NANS is linked to infection.