Microsporidiosis is a relatively unknown disease in man but is being increasingly diagnosed in humans today, particularly in AIDS patients. Debilitating clinical symptoms include keratitis, diarrhea, peritonitis, and hepatitis. Definitive diagnosis of microsporidiosis depends upon electron microscopic examination. Serologic diagnoses are inconsistent because the only available parasite antigen source was a mammalian microsporidian that commonly infects laboratory animals, but has not been commonly recovered from man. Reliable diagnostic tests and effective drugs are needed for clinical management of human microsporidiosis. The first and only human microsporidian, Nosema corneum, is now available in sufficient quantities for use in experimental studies. This will allow us to characterize and define N. corneum biochemically (by protein gel electrophoresis), immunologically (by western blot immunodetection), and molecularly (by comparative rRNA sequencing). Diagnostic tests, using western immunoblot assays, will then be developed for reliable detection of ocular microsporidiosis. Monoclonal antibodies will be produced for detection of N. corneum in biopsy materials, and microsporidial probes will be constructed using polymerase chain reaction technology. A murine animal model for systemic microsporidiosis will be extended to study the pathobiology of ocular microsporidiosis, and after screening three potential anti-microsporidial drugs in vitro, will be used to examine drug efficacy in vivo.
