Lung abscess

Epidemiology

Bacterial (pyogenic lung abscess)
- Most commonly caused by anaerobic bacteria that colonize the oral cavity (e.g., Peptostreptococcus spp., Prevotella spp., Bacteroides spp., Fusobacterium spp.)
- Less commonly caused by aerobic bacteria, such as: Staphylococcus aureus
  - The most virulent strains of S aureus have been infected with a bacteriophage that transmits genes for Panton-Valentine leukocidin (PVL), a cytotoxin that destroys leukocytes and causes tissue necrosis. PVL is primarily seen in community-acquired strains of S aureus that are methicillin-resistant (methicillin-resistance is conferred by a different mobile genetic element mecA).

Tip

One of the most severe complications of influenza in children and adults is a secondary bacterial infection with Staphylococcus aureus.