RESUMO
The molecular biology era, together with morphology, molecular phylogenetics, bioinformatics, and high-throughput sequencing technologies, improved the taxonomic identification of Argasidae family members, especially when considering specimens at different development stages, which remains a great difficulty for acarologists. These tools could provide important data and insights on the history and evolutionary relationships of argasids. To better understand these relationships, we sequenced and assembled the first complete mitochondrial genome of Nothoaspis amazoniensis. We used phylogenomics to identify the evolutionary history of this species of tick, comparing the data obtained with 26 complete mitochondrial sequences available in biological databases. The results demonstrated the absence of genetic rearrangements, high similarity and identity, and a close organizational link between the mitogenomes of N. amazoniensis and other argasids analyzed. In addition, the mitogenome had a monophyletic cladistic taxonomic arrangement, encompassed by representatives of the Afrotropical and Neotropical regions, with specific parasitism in bats, which may be indicative of an evolutionary process of cospeciation between vectors and the host.
RESUMO
The aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsial-endemic regions in Brazil. In the municipalities of Pingo D'Agua and Santa Cruz do Escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. In some serum samples from opossums (Didelphis aurita) captured in Santa Cruz do Escalvado, serologic response against rickettsiae was also verified. Polymerase chain reaction identified rickettsiae only in ticks and fleas obtained in Santa Cruz do Escalvado. Rickettsiae in samples had 100% sequence homology with Rickettsia felis. These results highlight the importance of marsupials in maintenance of the sylvatic cycle of rickettsial disease and potential integration with the domestic cycle. Our data also support the importance of horses and dogs as sentinels in monitoring circulation of rickettsiae in an urban area.