Campos Sabrina Destri Emmerick, Cunha Nathalie Costa da, Machado Camila de Souza Cerqueira, Nadal Niara Vanat, Seabra Junior Eloy Silva, Telleria Erich Loza, Cordeiro Matheus Dias, Toma Helena Keiko, Almosny Nádia Regina Pereira
Faculdade de Veterinária, Universidade Federal Fluminense - UFF, Niterói, RJ, Brasil.
Laboratório de Biologia Molecular de Parasitos e Vetores, Fundação Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, RJ, Brasil.
Rev Bras Parasitol Vet. 2020 Apr 6;29(1):e020219. doi: 10.1590/S1984-29612020012. eCollection 2020.
Rickettsia rickettsii is the causative agent of Brazilian spotted fever (BSF), for which humans and dogs are both susceptible. Dogs are sentinels in serological surveys, however, canine disease is rarely reported. Therefore, we aimed to evaluate natural infection by spotted fever group (SFG) Rickettsia spp. in dogs and ticks collected from domiciles close to forest fragments, featuring domestic-wildlife interface areas. Samples from 115 dogs and 135 ixodids were assessed by polymerase chain reactions (PCR) targeting the gltA gene for Rickettsia spp. and the ompA gene for the SFG rickettsial species. One dog (0.87%; 1/115) was positive for R. rickettsii. This dog presented nonspecific laboratory and clinical abnormalities (thrombocytopenia, hyperproteinemia, lymph node enlargement, emaciation, anorexia, and lethargy). Rickettsia parkeri was identified in 2.96% (4/135) of the ticks (Amblyomma sculptum, A. aureolatum, and Rhipicephalus sanguineus). This study confirmed the presence of SFG bacteria in non-endemic and preserved locations, where domestic and wild populations interact. We reinforce the fact that the dog is susceptible to natural R. rickettsii infection. Although this is a rare finding, preventive measures should be taken against BSF in the studied areas. Finally, R. parkeri infection is possibly being demonstrated in A. sculptum for the first time.
立氏立克次体是巴西斑点热（BSF）的病原体，人类和狗对此均易感。狗是血清学调查中的哨兵，然而，犬类疾病却鲜有报道。因此，我们旨在评估从靠近森林碎片的住所收集的狗和蜱中斑点热群（SFG）立克次体属的自然感染情况，这些住所具有 domestic-wildlife 界面区域。通过针对立克次体属的 gltA 基因和 SFG 立克次体物种的 ompA 基因的聚合酶链反应（PCR），对 115 只狗和 135 只硬蜱的样本进行了评估。一只狗（0.87%；1/115）立氏立克次体呈阳性。这只狗出现了非特异性的实验室和临床异常（血小板减少、高蛋白血症、淋巴结肿大、消瘦、厌食和嗜睡）。在 2.96%（4/135）的蜱（刻点钝缘蜱、金黄钝缘蜱和血红扇头蜱）中鉴定出帕克立克次体。本研究证实了在国内和野生种群相互作用的非流行和保护区存在 SFG 细菌。我们强调狗易受立氏立克次体自然感染这一事实。尽管这是一个罕见的发现，但在研究区域应采取针对巴西斑点热的预防措施。最后，帕克立克次体感染可能首次在刻点钝缘蜱中得到证实。
