Pesquisa do agente da Febre Maculosa Rickettsia parkeri cepa Mata Atlântica no Estado de Minas Gerais

Abstract

Ticks are hematophagous ectoparasites responsible for transmitting diseases to humans and an-imals. Among these diseases, Brazilian Spotted Fever, caused by Rickettsia rickettsii, stands out due to its high lethality when diagnosed late. Confirmed cases of this disease are closely associated with ticks of the genus Amblyomma, which represents the greatest diversity of ixodid species in Brazil. On the other hand, other species of the genus Rickettsia, such as Rickettsia parkeri Atlantic rainforest strain (ARF), may cause milder and frequently underdiagnosed clin-ical manifestations, although they still hold epidemiological importance. Minas Gerais is a state of large geographic proportions, with areas that favor the circulation of both bacteria, as well as their vectors. However, R. parkeri ARF , associated with its main vector Amblyomma ovale, had never been reported in this state. In this study, divided into two articles, we evaluated in the state of Minas Gerais the exposure of dogs, important sentinels of this disease, to the rick-ettsial antigens, as well as the presence of genetic material in ticks, in addition to assessing the seasonality of A. ovale, the main vector of R. parkeri ARF. These observations allowed us to conclude that the vector A. ovale shows higher frequency and abundance in spring, with greater intensity in November. Furthermore, the results provided evidence of exposure to rickettsial antigens in dogs from rural properties in the state of Minas Gerais, Brazil. Furthermore, the presence of R. parkeri ARF DNA was detected in two A. ovale ticks, constituting the first report of this bacterium associated with this tick in Minas Gerais.