Detection of Coccidioides fungi from the soil and air in the Southwestern United States

Abstract:

Coccidioidomycosis, commonly known as Valley fever, is an infectious disease caused by inhaling soil-dwelling fungi (Coccidioides immitis and C. posadasii). The disease is likely to spread wide and the number of the cases is predicted to increase substantially because of the climate changes. However effective control and prevention measures are still not available due to gaps in some key knowledge. Our study aims to develop large scale monitoring network and reliable laboratory detection of Cocci fungi in the soil and air dust in a cost-effective way. Soil and air samples were collected through three field trips, two in 2019 and one in 2020, from Arizona, California, New Mexico and Texas. Air samples are being continuously collected from five locations the Phoenix-Tuscan endemic area using various low-cost air samplers that include the Marble Dust Collector and Big Spring Number Eight. We also developed laboratory capability to screen and detect Coccidioides fungus from large amount of complex environmental samples using Multitag sequencing and quantitative polymerase chain reaction (qPCR) methods. Our preliminary results revealed high diverse of the soil samples from southern California, Texas and New Mexico based on the fungal and bacterial community compositions. The characterization of microbial communities can also provide insights about the ecology of the Velley fever fungus and the interactions within the microbial communities in soil and air samples.