Detection and phylogenetic analysis of Coccidioides posadasii in Arizona soil samples

► We screen desert soils for the presence of Coccidioides, the valley fever pathogen. ► Susceptible mice make a sensitive biosensor for recovering Coccidioides from soil. ► Soil factors inhibited direct PCR and direct soil culture. ► Genotypes of strains in a soil site may be clonal or diverse. ► Environmental strain genotypes were similar to clinical isolates from the same area.