title: Molecular detection of airborne Coccidioides in Tucson, Arizona.
abstract: Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detecting Coccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.
authors.affiliation: Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia yln3@cdc.gov frq8@cdc.gov.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Chow
authors.affiliation: US Geological Survey, Coastal and Marine Science Center, St. Petersburg, Florida.
authors.forename: Dale W
authors.initials: DW
authors.lastname: Griffin
authors.affiliation: Division of Pathogen Genomics, Translational Genomics Research Institute, Flagstaff, Arizona Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona Valley Fever Center for Excellence, University of Arizona, Tucson, Arizona.
authors.forename: Bridget M
authors.initials: BM
authors.lastname: Barker
authors.affiliation: Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Loparev
authors.affiliation: Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia yln3@cdc.gov frq8@cdc.gov.
authors.forename: Anastasia P
authors.initials: AP
authors.lastname: Litvintseva
mesh_terms: D000391:Air Microbiology; D001130:Arizona; D003045:Coccidioides / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008828:Microbiological Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012988:Soil Microbiology
keywords: Coccidioides; Valley fever; air/dust samples; atmospheric sampling; molecular detection