Source | Most commonly cultured organisms |
Paranasal sinus infection | Streptococcus spp. Staphylococcus spp. Enterobacteriaceae (especially Hemophilus spp., Pseudomonas aeruginosa) |
Otogenic infection | Proteus mirabilis Streptococcus milleri group organisms Streptococcus pneumoniae Staphylococcus aureus |
Dental infection | Streptococcus spp. Bacteroides fragilis |
Traumatic brain injury | Staphylococcus aureus Staphylococcus epidermidis Enterobacteriaceae (most commonly P. aeruginosa, Enterobacter spp.) |
Neurosurgical procedure | Staphylococcus aureus Staphylococcus epidermidis Pseudomonas aeruginosa Propionibacterium acnes Streptococcus spp. |
Hematogenous spread | Staphylococcus aureus Streptococcus viridans Klebsiella pneumoniae |