D-115. Panton-Valentine Leukocidin (PVL) Plays a Role in Pathogenesis in a Murine Skin Infection Model

C. Tseng1, P. Kyme1, M. A. Rocha2, D. O. Beenhouwer2,3, G. Liu1;
1Cedars-Sinai Med. Ctr., Los Angeles, CA, 2VA Greater Los Angeles Healthcare System, Los Angeles, CA, 3David Geffen Sch. of Med. at Univ. of California, Los Angeles, CA.

Panton-Valentine leukocidin (PVL) is a two-component pore forming toxin encoded by lukS-PV and lukF-PV, found commonly in community associated methicillin resistant Staphylococcus aureus (CA-MRSA) strains. Epidemiologic studies suggest that PVL plays a role in human staphylococcal disease, including necrotizing pneumonia and severe skin and soft tissue infections. However, studies of PVL virulence function in murine infection models have yielded conflicting results. We investigated the role of PVL in a murine skin infection model. CD1 mice were injected subcutaneously with isogenic PVL expressing and non-expressing strains. Three days after inoculation, lesions were measured and examined histopathologically and cytokines were assessed by ELISA. While skin surface lesions were similar in size, mice receiving PVL-expressing strains developed significantly larger lesions in the subcutaneous muscle tissue (p < 0.05). Furthermore, mice treated with rabbit antisera to PVL had significantly smaller muscle lesions (p < 0.05) comparing to those received PBS. These results demonstrated a specific role for PVL in severity and extension of skin infection caused by S. aureus in CD1 mice.