Panton Valentine Leukocidin (PVL)

Panton-Valentine leukocidin (PVL) is a cytotoxin—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. PVL causes leukocyte destruction and necrotizing pneumonia, an aggressive condition that often kills patients within 72 hours. Comparing cases of staphylococcal necrotizing pneumonia, 85% of community-acquired (CAP) cases were PVL-positive, while none of the hospital-acquired cases were.