Cerebral botryomycosis: case study.

After oral surgery, a 32-year-old man developed a brain abscess. Actinomycosis was suspected due to history, clinical findings, response to penicillin therapy, and demonstration of "sulfur granules" in the surgical specimen, but anaerobic cultures were negative for Actinomyces. Aerobic cultures yielded Streptococcus sanguis and Pseudomonas cepacia. Coccoid organisms demonstrated histologically reacted positively with periodic acid-Schiff, Gomori's methenamine silver, and Brown and Brenn stains, were Ziehl-Neelsen-negative, and did not include branching filaments. Fluorescent antibody assay for Actinomyces israelii was also negative. Electron microscopy revealed cell wall morphology and pattern of cell division characteristic of gram-positive cocci. These findings led to a final diagnosis of botromycosis due to S. sanguis. This third report of cerebral botryomycosis emphasizes the differential diagnosis with actinomycosis, the association with intermittently treated jaw disease, and identification of the causative agent by histologic, immunologic, and electron microscopic methods.