Silva Arannadia Barbosa, Vizzoni Vinicius Figueiredo, Costa Andréa Pereira, Costa Francisco Borges, Moraes-Filho Jonas, Labruna Marcelo Bahia, Gazêta Gilberto Salles, de Maria Seabra Nogueira Rita
Programa de Pós-graduação do Mestrado em Ciência Animal, Universidade Estadual do Maranhão, São Luís, Maranhão, MA, Brazil; Fundação Oswaldo Cruz/Instituto Oswaldo Cruz (FIOCRUZ/IOC), Laboratório de Referência Nacional em Vetores das Riquetsioses (LIRN), Rio de Janeiro, RJ, Brazil.
Fundação Oswaldo Cruz/Instituto Oswaldo Cruz (FIOCRUZ/IOC), Laboratório de Referência Nacional em Vetores das Riquetsioses (LIRN), Rio de Janeiro, RJ, Brazil.
Acta Trop. 2017 Aug;172:44-49. doi: 10.1016/j.actatropica.2017.04.004. Epub 2017 Apr 17.
The present study was performed in a non-endemic area for spotted fever (SF) in Imperatriz microregion, state of Maranhão, Brazil. Blood samples and ectoparasites were collected from 300 dogs of the Imperatriz microregion. Canine serum samples were tested individually by indirect immunofluorescence assay (IFA), using five Rickettsia isolates from Brazil. Antibodies reactive to at least one of the five species of Rickettsia were detected in 1.6% of the dogs (5/300). These sera were considered reactive to Rickettsia rickettsii and Rickettsia amblyommatis or very closely related species. The ticks (Acari: Ixodidae), identified as Rhipicephalus sanguineus sensu lato (Latreille), and the fleas, identified as Ctenocephalides felis, were tested by polymerase chain reaction (PCR) for detection of rickettsial DNA. More than 78% (83/106) of the C. felis fleas were found to be infected with Rickettsia species using gltA as rickettsial PCR targets, whereas no evidence of Rickettsia spp. was found in R. sanguineus s. l. Genetic analysis based on genes gltA, htrA and ompB showed that the detected strain, is most closely related to Rickettsia asembonensis (formerly Candidatus Rickettsia asemboensis). The present study is the first report of a R. asembonensis related infecting C. felis fleas in Brazil.
本研究在巴西马拉尼昂州因佩拉特里斯微地区的一个斑疹热非流行区进行。从因佩拉特里斯微地区的300只狗身上采集了血液样本和外寄生虫。使用来自巴西的5株立克次氏体分离株，通过间接免疫荧光试验（IFA）对犬血清样本进行单独检测。在1.6%（5/300）的狗中检测到对至少5种立克次氏体中的一种有反应的抗体。这些血清被认为对立氏立克次氏体和钝缘蜱立克次氏体或密切相关的物种有反应。将鉴定为血红扇头蜱（狭义）（拉特雷尔）的蜱（蜱螨目：硬蜱科）和鉴定为猫栉首蚤的跳蚤通过聚合酶链反应（PCR）检测立克次氏体DNA。以gltA作为立克次氏体PCR靶标，发现超过78%（83/106）的猫栉首蚤感染了立克次氏体物种，而在血红扇头蜱狭义中未发现立克次氏体属的证据。基于gltA、htrA和ompB基因的遗传分析表明，检测到的菌株与阿森博立克次氏体（以前的候选阿森博立克次氏体）关系最为密切。本研究是巴西首次报道与阿森博立克次氏体相关的猫栉首蚤感染。
