of Staphylococcus aureus Producing Phenol-Soluble Modulins

Staphylococcus aureus strains (n 50) causing complicated skin and skin structure infections produced various levels of phenol-soluble modulin alpha-type (PSM) peptides; some produced more than twice that produced by the control strain (LAC USA300). TR-700 (oxazolidinone) and clindamycin strongly inhibited PSM production at one-half the MIC but exhibited weak to modest induction at one-fourth and one-eighth the MICs, primarily in low producers. Adequate dosing of these agents is emphasized to minimize the potential for paradoxical induction of virulence. Secreted exotoxins such as toxic shock syndrome toxin 1 (TSST-1), -hemolysin (Hla), and Panton-Valentine leuko-cidin (PVL) have been shown to contribute in part to the viru-lence of Staphylococcus aureus (1, 2, 14). The phenol-soluble modulin alpha-type (PSM) peptides (1–4) are one of the most recently discovered peptides that have been implicated in the pathogenesis of community-associated methicillin-resistant S. aureus (CA-MRSA) complicated skin and skin structure infections (cSSSIs), bacteremia, and pneumonia (2, 16). Like the PV