The etiologic agent of Pacific Coast tick fever (PCTF), a moderately severe tickborne illness that resembles Rocky Mountain spotted fever (RMSF), was first isolated in 1966 from specimens of Dermacentor occidentalis (the Pacific Coast tick) obtained in California. For several decades, this bacterium was identified ambiguously as the unclassified spotted fever group Rickettsia species 364-D, Rickettsia 364, or Rickettsia philipii. However, none of these epithets satisfied criteria of formal bacterial nomenclature. Data developed from mouse serotyping studies performed 45 years ago, and multi-locus sequence typing several decades later, indicated that this bacterium was similar to, but distinct from isolates of Rickettsia rickettsii, the etiological agent of RMSF. We applied an integrative taxonomic approach, combining phenotypic, ecological, and clinical data with whole genome sequencing of 11 contemporary isolates of this pathogen to identify it as a distinct subspecies of R. rickettsii, and propose the name Rickettsia rickettsii subsp. californica subsp. nov.

中文翻译：

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立克次体 加利福尼亚立克次体 subsp. nov.，太平洋海岸蜱热的病原体


太平洋海岸蜱热 （PCTF） 是一种类似于落基山斑疹热 （RMSF） 的中度严重蜱传疾病，其病原体于 1966 年首次从加利福尼亚获得的西氏革蜱（太平洋海岸蜱虫）标本中分离出来。几十年来，这种细菌被模棱两可地确定为未分类的斑疹热组立克次体 364-D、立克次体 364 或菲律宾立克次体。然而，这些绰号都不符合正式细菌命名的标准。从 45 年前进行的小鼠血清分型研究和几十年后的多位点序列分型中获得的数据表明，这种细菌与 RMSF 的病原体立克次体分离株相似，但不同。我们应用了一种综合分类学方法，将表型、生态学和临床数据与该病原体的 11 种当代分离株的全基因组测序相结合，将其确定为立克次体的一个独特亚种，并提出了立克次体亚种 californica subsp. nov.