Organism

Empyema

Neonate: E. coli (GNR), group A or B streptococcus (GPC), S. aureus (GPC), Pseudomonas sp. (GNR).

Infant/child (<5 years): S. aureus (60%) (GPC), S. pneumoniae (27%) (GPC), H. influenzae (GNCB), anaerobes.

Child (>5 years)/adult, acute: S. pneumoniae (GPC), group A streptococcus (GPC), S. aureus (GPC), H. influenzae (GNCB), legionella, coagulase-negative staphylococci, viridans streptococci (GPC in chains).

Child (>5 years)/adult, chronic: Anaerobic streptococci, Bacteroides sp., Prevotella sp., Porphyromonas sp., Fusobacterium sp. (anaerobes 36–76%), Enterobacteriaceae, E. coli, Klebsiella pneumoniae, M. tuberculosis, Actinomyces sp.