Destroys leukocytes and is linked to necrotizing skin and pulmonary infections?

• A. Panton-Valentine leukocidin
• B. Protein A
• C. Exotoxin A
• D. M protein

Answer: (A)

Panton-Valentine leukocidin is a leukocidal toxin produced by some Staphylococcus aureus strains that forms pores in neutrophils and other leukocytes, causing their destruction. This targeted killing of white blood cells helps explain why these bacteria can cause severe necrotizing skin infections and necrotizing pneumonia, especially with community-associated MRSA strains. Other virulence factors have different roles: Protein A interferes with antibody opsonization rather than leukocyte destruction; Exotoxin A from Pseudomonas aeruginosa inhibits protein synthesis; M protein from Streptococcus pyogenes mainly aids in adhesion and immune evasion. The toxin that best fits the description of destroying leukocytes and being linked to necrotizing skin and pulmonary infections is Panton-Valentine leukocidin.