Coccidioides posadasii is a pathogenic fungus that causes coccidioidomycosis in many arid regions of the Americas. One of these regions is bordered by the Caribbean Sea, and the surrounding landscape may play an important role in the dispersion of C. posadasii across South America through southeastern Mexico, Honduras, Guatemala, and Venezuela. Comparative phylogenomic analyses of C. posadasii reveal that clinical strains from Venezuela are genetically distinct from the North American populations found in (i) Arizona and (ii) Texas, Mexico, and the rest of South America (TX/MX/SA). We find evidence for admixture between the Venezuela and the North American populations of C. posadasii in Central America. Additionally, the proportion of Venezuelan alleles in the admixed population decreases as latitude (and distance from Venezuela) increases. Our results indicate that the population in Venezuela may have been subjected to a recent bottleneck and shows a strong population structure. This analysis provides insight into potential for Coccidioides spp. to invade new regions.IMPORTANCE Valley Fever is a fungal disease caused by two species of fungi: Coccidioides immitis and C. posadasii These fungi are found throughout the arid regions of North and South America; however, our understanding of genetic diversity and disease in South America is limited. In this report, we analyze 10 new genomes of Coccidioides posadasii from regions bordering the Caribbean Sea. We show that these populations are distinct and that isolates from Venezuela are likely a result of a recent bottleneck. These data point to patterns that might be observed when investigating recently established populations.

中文翻译：

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委内瑞拉及周边地区 Coccidioides posadasii 分离株的种群结构和遗传多样性。

Coccidioides posadasii 是一种致病真菌，可在美洲许多干旱地区引起球孢子菌病。这些地区之一与加勒比海接壤，周围的景观可能对 C. posadasii 通过墨西哥东南部、洪都拉斯、危地马拉和委内瑞拉在南美洲的扩散起到重要作用。C. posadasii 的比较系统基因组学分析表明，来自委内瑞拉的临床菌株在遗传上不同于 (i) 亚利桑那州和 (ii) 德克萨斯州、墨西哥和南美洲其他地区 (TX/MX/SA) 中发现的北美种群。我们找到了委内瑞拉和中美洲 C. posadasii 的北美种群之间混合的证据。此外，随着纬度（以及与委内瑞拉的距离）的增加，混合种群中委内瑞拉等位基因的比例降低。我们的结果表明，委内瑞拉的人口可能受到最近的瓶颈影响，并显示出强大的人口结构。该分析提供了对 Coccidioides spp. 潜力的洞察。入侵新地区。重要性谷热是由两种真菌引起的真菌病：Coccidioides immitis 和 C. posadasii 这些真菌遍布北美和南美的干旱地区；然而，我们对南美洲遗传多样性和疾病的了解是有限的。在这份报告中，我们分析了来自加勒比海沿岸地区的 10 个新的 Coccidioides posadasii 基因组。我们表明这些种群是不同的，从委内瑞拉分离出来的可能是最近瓶颈的结果。这些数据指出了在调查最近建立的种群时可能观察到的模式。