Local Population Structure and Patterns of Western Hemisphere Dispersal for Coccidioides spp., the Fungal Cause of Valley Fever.
Local Population Structure and Patterns of Western Hemisphere Dispersal for Coccidioides spp., the Fungal Cause of Valley Fever.
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DOI：
10.1128/mbio.00550-16
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发表时间：
2016-04-26
期刊：
影响因子：
6.4
通讯作者：
Litvintseva AP
中科院分区：
文献类型：
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作者：
Engelthaler DM;Roe CC;Hepp CM;Teixeira M;Driebe EM;Schupp JM;Gade L;Waddell V;Komatsu K;Arathoon E;Logemann H;Thompson GR 3rd;Chiller T;Barker B;Keim P;Litvintseva AP
球孢子菌病（或谷热）是一种发病率和死亡率很高的真菌病，每年影响数万人。这种感染是由两种兄弟物种引起的，即 Coccidioides immitis 和 C. posadasii，它们是整个西半球特定干旱地区的特有种，特别是美国西南部的沙漠。最近的流行病学和群体遗传学数据表明，球孢子菌病的地理范围正在扩大，因为在华盛顿州发现了新的地方病群，远远超出了既定的地方病范围。这种扩张的遗传机制和流行病学后果尚不清楚，需要更好地了解这些病原体的种群结构和进化历史。在这里，我们对 68 个新基因组和 18 个先前发表的基因组进行了多重系统发育推断和群体基因组学分析。结果提供了 C. posadasii 大量种群结构的证据，并证明了亚利桑那州中部和南部存在不同的地理分支，以及德克萨斯州、墨西哥、南美洲和中美洲的分散种群。尽管分析中包含了较少数量的 C. immitis 菌株，但在该物种中也检测到了一些系统发育地理结构的证据，该物种历史上仅限于加利福尼亚州和墨西哥巴哈。贝叶斯分析表明，C. posadasii 是这两个物种中更古老的，亚利桑那州拥有最多样化的亚群。我们提出了 C. posadasii 的起源于亚利桑那州南部 - 墨西哥北部，并描述了该地区的扩散和分布途径。球孢子菌病或谷热是由致病真菌 Coccidioides posadasii 和 C.immitis 引起的。这种真菌种类和疾病主要发现于美国西南部的沙漠，在整个西半球有斑点分布。最初的分子研究表明，C. posadasii 可能是从北美到南美的人为迁移。在这里，我们比较分析了两个球孢子菌属物种的 86 个基因组，并建立了当地和物种范围的种群结构，不仅澄清了早期的扩散假设，而且还为已知的球孢子菌亚种群的可能祖先种群和扩散模式提供了证据。
Coccidioidomycosis (or valley fever) is a fungal disease with high morbidity and mortality that affects tens of thousands of people each year. This infection is caused by two sibling species, Coccidioides immitis and C. posadasii, which are endemic to specific arid locales throughout the Western Hemisphere, particularly the desert southwest of the United States. Recent epidemiological and population genetic data suggest that the geographic range of coccidioidomycosis is expanding, as new endemic clusters have been identified in the state of Washington, well outside the established endemic range. The genetic mechanisms and epidemiological consequences of this expansion are unknown and require better understanding of the population structure and evolutionary history of these pathogens. Here we performed multiple phylogenetic inference and population genomics analyses of 68 new and 18 previously published genomes. The results provide evidence of substantial population structure in C. posadasii and demonstrate the presence of distinct geographic clades in central and southern Arizona as well as dispersed populations in Texas, Mexico, South America, and Central America. Although a smaller number of C. immitis strains were included in the analyses, some evidence of phylogeographic structure was also detected in this species, which has been historically limited to California and Baja, Mexico. Bayesian analyses indicated that C. posadasii is the more ancient of the two species and that Arizona contains the most diverse subpopulations. We propose a southern Arizona-northern Mexico origin for C. posadasii and describe a pathway for dispersal and distribution out of this region. Coccidioidomycosis, or valley fever, is caused by the pathogenic fungi Coccidioides posadasii and C. immitis. The fungal species and disease are primarily found in the American desert southwest, with spotted distribution throughout the Western Hemisphere. Initial molecular studies suggested a likely anthropogenic movement of C. posadasii from North America to South America. Here we comparatively analyze eighty-six genomes of the two Coccidioides species and establish local and species-wide population structures to not only clarify the earlier dispersal hypothesis but also provide evidence of likely ancestral populations and patterns of dispersal for the known subpopulations of C. posadasii.