Radosevich Molly, Head Jennifer, Couper Lisa, Gomez-Weaver Amanda, Camponuri Simon, Montoya Liliam, Taylor John, Remais Justin
Division of Environmental Health Sciences, University of California, Berkeley, Berkeley, California, 94720.
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
bioRxiv. 2024 Sep 28:2024.09.27.615053. doi: 10.1101/2024.09.27.615053.
Coccidioidomycosis is a fungal disease affecting humans and other mammals, caused by environmental pathogens of the genus . Understanding the ecological factors that shape the distribution of in soils is important for minimizing the risk of human exposure, though this remains challenging due to the pathogen's highly variable spatial distribution. Here, we examined associations between the soil microbial community and presence within the Carrizo Plain National Monument-a minimally disturbed grassland ecosystem, and the site of a longitudinal study examining the effects of rodents and their burrows on presence in soils. Using internal transcribed spacer 2 (ITS2) and 16S sequencing to characterize the soil fungal and bacterial communities, we found over 30 fungal species, including several other members of the Onygenales order, that co-occurred with more frequently than expected by chance. -positive samples were significantly higher in microbial diversity than negative samples, an association partly driven by higher presence within rodent burrows compared to surface soils. Soil source ( rodent burrow versus surface soil) explained the largest amount of variation in bacterial and fungal community diversity and composition, with soils collected from rodent burrows having higher microbial diversity than those collected from adjacent surface soils. While prior evidence is mixed regarding associations between and microbial diversity, our study suggests that favorable microhabitats such as rodent burrows can lead to a positive association between soil diversity and presence, particularly in otherwise resource-limited natural environments.
球孢子菌病是一种影响人类和其他哺乳动物的真菌疾病,由该属的环境病原体引起。了解影响土壤中该病原体分布的生态因素对于将人类暴露风险降至最低很重要,不过由于病原体的空间分布高度可变,这仍然具有挑战性。在这里,我们研究了卡里佐平原国家纪念区内土壤微生物群落与该病原体存在之间的关联,该纪念区是一个受干扰最小的草原生态系统,也是一项纵向研究的地点,该研究考察了啮齿动物及其洞穴对土壤中该病原体存在的影响。我们使用内部转录间隔区2(ITS2)和16S测序来表征土壤真菌和细菌群落,发现了30多种真菌物种,包括爪甲团囊菌目(Onygenales)的其他几个成员,它们与该病原体同时出现的频率高于偶然预期。阳性样本的微生物多样性显著高于阴性样本,这种关联部分是由于与表层土壤相比,啮齿动物洞穴内该病原体的存在量更高。土壤来源(啮齿动物洞穴与表层土壤)解释了细菌和真菌群落多样性及组成变化的最大部分,从啮齿动物洞穴收集的土壤比从相邻表层土壤收集的土壤具有更高的微生物多样性。虽然之前关于该病原体与微生物多样性之间关联的证据不一,但我们的研究表明,啮齿动物洞穴等有利的微生境可导致土壤多样性与该病原体存在之间呈正相关,特别是在其他方面资源有限的自然环境中。