Etiological agent and primary source of infection in 42 cases of focal intracranial suppuration.

The microbiological findings for 42 patients with focal intracranial suppuration were analyzed and correlated with the different sources of primary infection. Streptococcus spp. were identified in focal intracranial suppuration of all origins except postcraniotomy. Microaerophilic streptococci were important in cases secondary to respiratory tract infection and in those of unknown origin. Streptococcus faecalis, Proteus spp., and Bacteroides fragilis were the organisms most commonly found in polymicrobial otogenic abscesses. Clostridium sp. was the main microorganism implicated in postcraniotomy suppurations.