Cell Wall-Associated Proteinases of Coccidioides Immitis

Coccidioides immitis is the causative agent of a human respiratory disease known as coccidioidomycosis (’cocci’ or valley fever), which is characterized by a multiplicity of clinical forms. Approximately 100,000 cases of this fungal disease are diagnosed annually in the United States, primarily on the basis of serological tests (Cole et al., 1990). Results of clinical studies of coccidioidomycosis have suggested that underlying immunological illnesses are not prerequisite to infection. On the other hand, immunocompromised patients such as those diagnosed with acquired immunodeficiency syndrome (AIDS) who have previously lived or currently reside in endemic areas have been reported to contract symptomatic coccidioidomycosis at an unpredicted high annual frequency (27%; Bronnimann et al., 1987). A large percentage of these cases may represent reactivation of an old infection. C. immitis is apparently able to persist in body organs in the absence of overt illness. The nature of this persistent form of the pathogen in host tissue is not known.