PVL LukS

Panton-Valentine leukocidin ( PVL ) is one of the β-pore-forming toxins. The presence of PVL is associated with increased virulence of certain strains (isolates) of Staphylococcus aureus. It is present in the majority of community-associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates studied and is the cause of necrotic lesions involving the skin or mucosa, including necrotic hemorrhagic pneumonia. PVL creates pores in the membranes of infected cells. PVL is produced from the genetic material of a bacteriophage that infects Staphylococcus aureus, making it more virulent. Exotoxins such as PVL constitute essential components of the virulence mechanisms of S. aureus. Nearly all strains secrete lethal factors that convert host tissues into nutrients required for bacterial growth. LukS-PV and LukF-PV act together as subunits, assembling in the membrane of host defense cells, in particular, white blood cells, monocytes, and macrophages. The subunits fit together and form a ring with a central pore through which cell contents leak and which acts as a superantigen. PVL causes leukocyte destruction and necrotizing pneumonia, an aggressive condition that can kill up to 75% of patients.