Phylogenetic Differentiation of Rickettsia parkeri Reveals Broad Dispersal and Distinct Clustering within North American Strains.
Phylogenetic Differentiation of Rickettsia parkeri Reveals Broad Dispersal and Distinct Clustering within North American Strains.
复制标题
帕克氏立克次体的系统发育分化揭示了北美菌株内的广泛分散和独特的聚类。
DOI：
10.1128/spectrum.01417-21
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发表时间：
2021-10-31
影响因子：
3.7
通讯作者：
Karpathy SE
中科院分区：
文献类型：
--
作者：
Allerdice MEJ;Paddock CD;Hecht JA;Goddard J;Karpathy SE
蜱传病原体帕克氏立克次体引起轻度立克次体病，从几个国家报告的病例到其在美洲的已知分布。分子分析已经确定了R.严格意义上的parkeri sensu stricto（s. s.）和R.广义parkeri（s.（图中为L.）以及北美和南美R.帕克里湾S.菌株为了扩展这一先前的工作，我们开发了一个多位点序列分型分析，有两个目的：第一，调查北美红曲霉菌株的遗传多样性。帕克里湾s.，二是进一步了解R.帕克里湾S.和R.帕克里湾L.六十四河parkeri分离株和12株R.使用由四个编码区和两个基因间区组成的新型分型方案分析帕克氏阳性蜱裂解物。构建了一个识别八个分支的串联贝叶斯进化树：三个代表R。帕克里湾L.菌株，5个代表R.帕克里湾S.菌株这些分支似乎在地理上是有组织的，并与特定的蜱虫媒介有关。然而，虽然四个R.帕克里湾S.北美分支似乎仅限于美国西南部，其他北美分支表现出广泛的分散，最值得注意的是在最大的群体中，其中包括从北方墨西哥延伸到特拉华州的代表性样本。这项工作突出了R的日益认可的地理范围。parkeri在美洲，并建议为这些地区的潜在公共卫生风险。重要性自1937年首次在斑点钝眼蜱群蜱中发现帕克氏立克次体以来，该病原体的识别范围和相关载体已显著扩大。近年来，R.在美洲7个国家的12种蜱类中发现了帕克氏蜱。在此，我们提供的证据表明，最大的遗传多样性内R。parkeri分布于北美洲，其中一株R. parkeri sensu lato和四个R.存在严格意义上的parkeri基因型。而一个不同的R.严格意义上的parkeri sensu stricto基因型仅存在于美国西南部，三种基因型广泛分布于美国东部，其中最大的基因型在已知的R.帕克里在北美。与此相反，南美的R.严格意义上的帕克氏病样品代表单一基因型，并且在所分析的基因座处是完全克隆的，而与它们的起源国无关。
The tick-borne pathogen Rickettsia parkeri causes a mild rickettsiosis, with cases reported from several countries to its known distribution in the Americas. Molecular analyses have identified a clear distinction between strains of R. parkeri sensu stricto (s. s.) and R. parkeri sensu lato (s. l.) as well as separation between North American and South American R. parkeri s. s. strains. To expand on this previous work, we developed a multilocus sequence typing analysis with two aims: first, to investigate the genetic diversity within strains of North American R. parkeri s. s., and second, to further the understanding of the genetic relationships between R. parkeri s. s. and R. parkeri s. l. Sixty-four R. parkeri isolates and 12 R. parkeri-positive tick lysates were analyzed using a novel typing scheme consisting of four coding regions and two intergenic regions. A concatenated Bayesian phylogeny that identified eight clades was constructed: three represent the R. parkeri s. l. strains, and five represent the R. parkeri s. s. strains. The clades appear to be generally phylogeographically organized and associated with specific tick vectors. However, while one of the four R. parkeri s. s. North American clades appears to be limited to the southwestern United States, the other North American clades exhibit broad dispersal, most notably seen in the largest group, which includes representative samples extending from northern Mexico to Delaware. This work highlights the increasingly recognized geographic range of R. parkeri in the Americas and suggests a potential public health risk for these areas. IMPORTANCE Since 1937, when Rickettsia parkeri was originally identified in Amblyomma maculatum group ticks, the recognized range and associated vectors for this pathogen have expanded significantly. In recent years, R. parkeri has been identified in 12 tick species from seven countries in the Americas. Herein, we provide evidence that the greatest genetic diversity within R. parkeri exists in North America, where one R. parkeri sensu lato and four R. parkeri sensu stricto genotypes are present. While one distinct R. parkeri sensu stricto genotype exists only in the southwestern United States, three genotypes are broadly distributed in the eastern United States, with the largest of these found across the known range of R. parkeri in North America. In contrast, the South American R. parkeri sensu stricto samples represent a single genotype and are completely clonal at the loci analyzed, irrespective of their country of origin.