Regulation of infectious spore formation in the fungal pathogen coccidioides posadasii

The National Institute of Allergy and Infectious Diseases (NIAID) awarded $438,038 to the Regents of the University of California, Berkeley, under the Allergy and Infectious Diseases Research program (CFDA 93.855) for a two-year project period running from July 15, 2025 through June 30, 2027. This Project Grant funds a molecular research initiative investigating the regulation of infectious spore formation in Coccidioides posadasii, the fungal pathogen responsible for valley fever—a treatment-refractory disease endemic to arid regions of the Western Hemisphere. The research applies experimental and computational genomic approaches to elucidate how the pathogen preferentially produces infectious spores under desiccated environmental conditions.

The research deliverables include identification of candidate genes underlying spore formation through genomic data analysis, characterization of the desiccation response mechanisms in Coccidioides outside the host environment, and discovery of environmentally-triggered phenotypes relevant to disease transmission. These outputs will advance the scientific understanding of valley fever transmission dynamics from environmental reservoirs and establish a new research foundation focused on the molecular basis of Coccidioides disease transmission, thereby supporting public health objectives for valley fever prediction and prevention in affected populations.

Abstract

The human fungal pathogen coccidioides causes valley fever, a treatment-refractory and sometimes deadly disease prevalent in arid regions of the western hemisphere. Patients contract the disease by inhaling fungal spores from soil. Understanding coccidioides behavior in the environment is thus key to public health measures for valley fever prediction and prevention. We propose a first-ever molecular study of the environmental life cycle of coccidioides toward this end. Our preliminary work has shown that coccidioides preferentially makes infectious spores in dry conditions. We now want to know how. We apply experimental- and computational- genomic approaches to dissect desiccation response in coccidioides outside the host. The rich data sources we generate will pinpoint candidate genes underlying spore formation and will also position US to discover other environmentally-triggered phenotypes in coccidioides. Our work will open a new wing of the research literature focused on the molecular basis of coccidioides disease transmission from the environment.