Comparative analysis of USA300 virulence determinants in a rabbit model of skin and soft tissue infection.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are frequently associated with strains harboring genes encoding Panton-Valentine leukocidin (PVL). The role of PVL in the success of the epidemic CA-MRSA strain USA300 remains unknown. Here we developed a skin and soft tissue infection model in rabbits to test the hypothesis that PVL contributes to USA300 pathogenesis and compare it with well-established virulence determinants: alpha-hemolysin (Hla), phenol-soluble modulin-alpha peptides (PSMα), and accessory gene regulator (Agr). The data indicate that Hla, PSMα, and Agr contribute to the pathogenesis of USA300 skin infections in rabbits, whereas a role for PVL could not be detected.