PantonValentine

Panton-Valentine leukocidin (PVL) is a pore-forming cytotoxin produced by certain strains of Staphylococcus aureus, including many community-associated methicillin-resistant S. aureus (CA-MRSA). It consists of two component toxins, LukF-PV and LukS-PV, encoded by adjacent genes lukF-PV and lukS-PV that are carried by specialized bacteriophages. The toxin is named after Fay Panton and R. Valentine, who described a leukocidal toxin produced by S. aureus in the 1930s.

PVL targets neutrophils and other leukocytes, forming pores in cell membranes and causing cell lysis. In humans, PVL is associated with skin and soft tissue infections such as furuncles, abscesses, and necrotizing purulent lesions, and with severe necrotizing pneumonia, which can progress rapidly and be fatal especially in children and young adults.

Despite associations with increased severity, the exact role of PVL in disease is debated. PVL genes are more common in community-associated MRSA strains, but not all PVL-positive infections are severe, and some virulent S. aureus strains lack PVL. It is considered a virulence factor that may contribute to pathogenesis in concert with other bacterial and host factors.

Diagnosis typically involves molecular tests to detect lukF-PV and lukS-PV genes (PCR). Laboratory assessment of toxin production is not routinely performed. Treatment follows guidelines for S. aureus infections and MRSA when present; some clinicians prefer antibiotics that suppress toxin production (e.g., clindamycin) in toxin-mediated disease. Infection control measures reduce transmission.