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Abstract：
Sporothrix (Ophiostomatales) comprises species that are pathogenic to humans and other mammals as well as environmental fungi. Developments in molecular phylogeny have changed our perceptions about the epidemiology, host-association, and virulence of Sporothrix. The classical agent of sporotrichosis, Sporothrix schenckii, now comprises several species nested in a clinical clade with S. brasiliensis, S. globosa, and S. luriei. To gain a more precise view of outbreaks dynamics, structure, and origin of genetic variation within and among populations of Sporothrix, we applied three sets of discriminatory AFLP markers (#3 EcoRI-GA/MseI-TT, #5 EcoRI-GA/MseI-AG, and #6 EcoRI-TA/MseI-AA) and mating-type analysis to a large collection of human, animal and environmental isolates spanning the major endemic areas. A total of 451 polymorphic loci were amplified in vitro from 188 samples, and revealed high polymorphism information content (PIC = 0.1765-0.2253), marker index (MI = 0.0001-0.0002), effective multiplex ratio (E = 15.1720-23.5591), resolving power (Rp = 26.1075-40.2795), discriminating power (D = 0.9766-0.9879), expected heterozygosity (H = 0.1957-0.2588), and mean heterozygosity (Havp = 0.000007-0.000009), demonstrating the effectiveness of AFLP markers to speciate Sporothrix. Analysis using the program structure indicated three genetic clusters matching S. brasiliensis (population 1), S. schenckii (population 2), and S. globosa (population 3), with the presence of patterns of admixture amongst all populations. AMOVA revealed highly structured clusters (PhiPT = 0.458-0.484, P < 0.0001), with roughly equivalent genetic variability within (46-48 %) and between (52-54 %) populations. Heterothallism was the exclusive mating strategy, and the distributions of MAT1-1 or MAT1-2 idiomorphs were not significantly skewed (1:1 ratio) for S. schenckii (χ2 = 2.522; P = 0.1122), supporting random mating. In contrast, skewed distributions were found for S. globosa (χ2 = 9.529; P = 0.0020) with a predominance of MAT1-1 isolates, and regional differences were highlighted for S. brasiliensis with the overwhelming occurrence of MAT1-2 in Rio de Janeiro (χ2 = 14.222; P = 0.0002) and Pernambuco (χ2 = 7.364; P = 0.0067), in comparison to a higher prevalence of MAT1-1 in the Rio Grande do Sul (χ2 = 7.364; P = 0.0067). Epidemiological trends reveal the geographic expansion of cat-transmitted sporotrichosis due to S. brasiliensis via founder effect. These data support Rio de Janeiro as the centre of origin that has led to the spread of this disease to other regions in Brazil. Our ability to reconstruct the source, spread, and evolution of the ongoing outbreaks from molecular data provides high-quality information for decision-making aimed at mitigating the progression of the disease. Other uses include surveillance, rapid diagnosis, case connectivity, and guiding access to appropriate antifungal treatment.
摘要：
孢子丝菌(Ophiostomatales)包括对人类和其他哺乳动物以及环境真菌具有致病性的物种。分子系统发育的发展改变了我们对流行病学的看法，主机协会，和孢子丝菌的毒力。孢子丝菌病的经典剂，申克氏孢子虫,现在包括几个物种嵌套在一个临床进化枝与巴西链球菌，S、globosa，还有S.luriei.为了获得更精确的疫情动态视图，结构,以及孢子丝虫种群内部和种群之间的遗传变异的起源，我们应用了三组歧视性AFLP标记(#3EcoRI-GA/MseI-TT，#5EcoRI-GA/MseI-AG,和＃6EcoRI-TA/MseI-AA）和大量人类的交配类型分析，跨越主要流行区的动物和环境分离株。从188个样品中体外扩增出451个多态位点,并显示出较高的多态性信息含量（PIC=0.1765-0.2253），标记指数(MI=0.0001-0.0002)，有效复用比(E=15.1720-23.5591)，分辨能力（Rp=26.1075-40.2795），鉴别力(D=0.9766-0.9879)，期望杂合度(H=0.1957-0.2588)，和平均杂合度(Havp=0.000007-0.000009)，证明AFLP标记对孢子丝菌的特异性有效。使用程序结构的分析表明三个遗传簇匹配巴西链球菌（种群1），S、申克（人口2），和S.globosa(人口3)，在所有人群中都存在混合模式。AMOVA显示高度结构化的簇（PhiPT=0.458-0.484，P<0.0001），在（46-48％）和（52-54％）种群之间具有大致相等的遗传变异性。异性恋是唯一的交配策略，申克S.的MAT1-1或MAT1-2同态分布没有显着偏斜（1：1比例）（χ2=2.522；P=0.122），支持随机交配。相比之下,在以MAT1-1分离株为主的球形链球菌(χ2=9.529;P=0.0020)中发现了偏态分布,巴西链球菌的区域差异突出显示，在里约热内卢（χ2=14.222；P=0.0002）和伯南布哥（χ2=7.364；P=0.0067），与南里奥格兰德州MAT1-1的患病率相比（χ2=7.364；P=0.0067）。流行病学趋势揭示了由于巴西链球菌通过创始人效应引起的猫传播的孢子丝菌病的地理扩展。这些数据支持里约热内卢是导致这种疾病传播到巴西其他地区的起源中心。我们重建源头的能力，传播，从分子数据中对正在进行的疫情的演变为旨在缓解疾病进展的决策提供了高质量的信息。其他用途包括监视，快速诊断,案例连接,并指导获得适当的抗真菌治疗。
