蜱传复发性发热组(RFG)borreliosis作为一种人类疾病仍然被忽视,在蜱和脊椎动物中的维持作用鲜为人知,尤其是在南美洲。因此,这项研究调查了在巴西半干旱地区的啮齿动物居住的岩层中收集的Ornithodorostick中的疏螺旋体感染,在Caatinga生物群落中。收集的蜱(Ornithodorosrietcorreai和Ornithodoros参见tabajara)被允许在实验室条件下喂养豚鼠,每天通过暗视野显微镜检查血液样本。在四只O.rietcoreai感染的豚鼠的血液中都没有可见螺旋体。相反,在三只豚鼠的血液中喂食蜱后9到39天之间观察到螺旋体,每个人都受到O.cf.tabajara从不同的地方滴答。通过进入实验动物并产生疏螺旋体的DNA序列来证实豚鼠的感染。来自有螺旋体血症的豚鼠的血液。三个O.cf.tabajara种群被相同的螺旋体生物感染,根据10个疏螺旋体基因座(rrs,FlaB,glpQ,gyrB,clpX,pepx,pyrG,recG,rplB和uvrA)。我们证明了O.cf.tabajara是小说Borreliasp的有力载体。隔离物,尽管没有感染的啮齿动物发展为临床疾病。
Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the Brazilian semiarid region, within the Caatinga biome. Collected ticks (Ornithodoros rietcorreai and Ornithodoros cf. tabajara) were allowed to feed under laboratory conditions on guinea pigs, which had blood samples examined daily by dark-field microscopy. No spirochetes were visualized in the blood of any of four O. rietcorreai-infested guinea pigs. Contrastingly, spirochetes were visualized between 9 and 39 days after tick feeding in the blood of three guinea pigs, each infested with O. cf. tabajara ticks from a different locality. Guinea pig infection was confirmed by passages into experimental animals and by generating DNA sequences of Borrelia spp. from the blood of spirochetemic guinea pigs. Three O. cf. tabajara populations were infected by the same borrelial organism, which was characterized as a novel RFG agent (named as \'Candidatus Borrelia caatinga\') based on 10 Borrelia loci (rrs, flaB, glpQ, gyrB, clpX, pepX, pyrG, recG, rplB and uvrA). We demonstrated that O. cf. tabajara is a competent vector of the novel Borrelia sp. isolates, although none of the infected rodents developed clinical illness.