Valley Fever Project

Fungal and Bacterial Communities in the Air Dust and Soil in the Southwestern US

Ling Ren1, Masoumeh Sikaroodi1, Daniel Tong1, Thomas Gill2, Scott Van Pelt3, Zachery Chester1, Patrick M. Gillevet1

  1. College of Science, George Mason University, 4400 University Dr., Fairfax VA 22030
  2. Department of Geological Sciences, University of Texas at El Paso, 591 W. University Ave.
    El Paso, TX 79968.
  3. Agriculture Research Service, US Department of Agriculture, 302W, I-20, Big Spring, TX, 79720.

Dust storms are predicted to increase substantially in the future due to climate changes and subsequent dryland expansions. During dust aerosolization, soil microorganisms, including many fungal and bacterial pathogens are increasingly injected into the atmosphere. Dust-associated microorganisms can cause a myriad of adverse health effects on humans as well as wildlife, livestock, and ecosystems. As an example, Coccidioidomycosis, commonly known as Valley fever, is an infectious disease caused by inhaling soil-dwelling fungi, Coccidioides immitis and C. posadasii. Diseases caused by airborne pathogens are widespread and the number of cases can be expected to rise due to the increase in dust events. We conducted a pilot study, aiming to evaluate the feasibility of developing a large-scale airborne dust monitoring network and reliable laboratory detection of microorganisms in a cost-effective way. Soil samples were collected from three field trips during 2019-2020, two in southern California, New Mexico and Texas, and one in Arizona. Dust samples have been collected every two months since March 2020 at five locations in the Phoenix-Tuscon endemic area in Arizona, using various low-cost samplers that include Marble Dust Collectors, Big Spring Number Eight dust collectors (Custom Products, Big Spring, Texas), and a Big Spring Aspirated Sampler. Multitag Next-Generation Sequencing was conducted to characterize the fungal and bacterial communities in soil and dust samples. We are also developing laboratory capability to screen and detect Coccidioides fungus using quantitative polymerase chain reaction (qPCR). Preliminary results revealed high biodiversity in fungal and bacterial communities in the soil. However, the species diversity in the air dust samples were significantly lower than that in soils. The community composition of fungi and bacteria in New Mexico and Texas soil samples were largely different from southern California. 

Real Time Community analysis at MBAC

Valley Fever is caused by Coccidioides imitis

Center for Spatial Information Science and Systems-Director Daniel Tong