Brain abscess

Microbiology

Nose/sinuses: Streptococcus spp (especially S. milleri), Haemophilus spp, Bacteroides spp, Fusobacterium spp
Teeth: Streptococcus spp, Bacteroides spp, Prevotella spp, Fusobacterium spp, Haemophilus spp
Ears: Enterobacteriaceae, Streptococcus spp, Pseudomonas aeruginosa, Bacteroides spp
Lungs: Streptococcus spp, Fusobacterium spp, Actinomyces spp
Urinary tract: Pseudomonas aeruginosa, Enterobacter spp
Penetrating head trauma: Staphylococcus aureus, Enterobacter spp, Clostridium spp
Neurosurgery: Staphylococcus spp, Streptococcus spp, Pseudomonas aeruginosa, Enterobacter spp
Endocarditis: Viridans streptococci, S. aureus
Congenital cardiac malformations (especially right-to-left shunts): Streptococcus spp
Plus anaerobes, which are common