Paddock Christopher D, Denison Amy M, Lash R Ryan, Liu Lindy, Bollweg Brigid C, Dahlgren F Scott, Kanamura Cristina T, Angerami Rodrigo N, Pereira dos Santos Fabiana C, Brasil Martines Roosecelis, Karpathy Sandor E
Infectious Diseases Pathology Branch and Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; Núcleo de Anatomica Patológia, Centro de Patologia do Instituto Adolfo Lutz, São Paulo, Brazil; Departamento de Vigilância em Saúde, Secretaria Municipal de Saúde de Campinas, São Paulo, Brazil
Infectious Diseases Pathology Branch and Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; Núcleo de Anatomica Patológia, Centro de Patologia do Instituto Adolfo Lutz, São Paulo, Brazil; Departamento de Vigilância em Saúde, Secretaria Municipal de Saúde de Campinas, São Paulo, Brazil.
Am J Trop Med Hyg. 2014 Sep;91(3):589-97. doi: 10.4269/ajtmh.14-0146. Epub 2014 Jun 23.
Rocky Mountain spotted fever (RMSF), a tick-borne zoonosis caused by Rickettsia rickettsii, is among the deadliest of all infectious diseases. To identify the distribution of various genotypes of R. rickettsii associated with fatal RMSF, we applied molecular typing methods to samples of DNA extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of RMSF. Complete sequences of one or more intergenic regions were amplified from tissues of 30 (29%) case-patients and revealed a distribution of genotypes consisting of four distinct clades, including the Hlp clade, regarded previously as a non-pathogenic strain of R. rickettsii. Distinct phylogeographic patterns were identified when composite case-patient and reference strain data were mapped to the state and country of origin. The phylogeography of R. rickettsii is likely determined by ecological and environmental factors that exist independently of the distribution of a particular tick vector.
落基山斑疹热（RMSF）是一种由立氏立克次体引起的蜱传人畜共患病，是所有传染病中最致命的疾病之一。为了确定与致命性RMSF相关的各种立氏立克次体基因型的分布，我们对从7个国家103例死于RMSF的尸检病例的福尔马林固定、石蜡包埋组织标本中提取的DNA样本应用了分子分型方法。从30例（29%）病例的组织中扩增出一个或多个基因间隔区的完整序列，结果显示基因型分布包括四个不同的进化枝，其中包括Hlp进化枝，该进化枝以前被认为是立氏立克次体的非致病菌株。当将综合病例和参考菌株数据映射到病例和参考菌株的来源州和国家时，确定了不同的系统地理学模式。立氏立克次体的系统地理学可能由独立于特定蜱传媒介分布的生态和环境因素决定。
