Fluconazole therapy in a rhesus monkey (Macaca mulatta) with epidural Trichosporon beigelii in a cephalic recording cylinder.

An adult female rhesus monkey with a cephalic recording cylinder surgically implanted over a craniotomy site developed cloudy cylinder fluid and a white gelatinous plaque on the epidural capsule surface. Results of baseline hematologic, serum biochemical, and cerebrospinal fluid analysis and simian retrovirus panel were unremarkable. Aerobic culture of the cylinder fluid yielded a pure culture of Trichosporon beigelii. This organism is a ubiquitous saprophytic fungus that is a potential pathogen, especially in the immunocompromised host. Factors that could have contributed to the infection included a microenvironment in the cylinder that was favorable to fungal growth, and presence of a dural pseudocapsule of collagen and granulation tissue in the implant which could have inhibited cellular defense mechanisms. An intravenous formulation of fluconazole was selected for direct application into the recording cylinder on the basis of safety and efficacy. Fluconazole is a highly water-soluble, metabolically stable bis-triazole antifungal with excellent cerebrospinal fluid penetration and low toxicity. A 4-week course of treatment eliminated Trichosporon organisms from the cylinder. Change to oral administration of fluconazole was made at that time to allow use of cephalic cylinder antibiotics that are incompatible with fluconazole. Further treatment with fluconazole was continued orally for 3 more months to prevent fungal recrudescence. Culture of cylinder fluid was performed periodically for 6 months after resolution, and results remained negative for T. beigelii. This case is believed to be the first reported T. beigelii infection in a non-human primate. Fluconazole was effective in eliminating the infection from the cylinder and preventing its recurrence.