Infecção por riquetsias em carrapatos de cães e do ambiente no entorno do Parque Estadual do Pau Furado, nos municípios de Araguari e Uberlândia, Minas Gerais

Abstract

Pathogenic microorganisms in natural areas are part of biodiversity. In general, these pathogens are restricted to the original environment by biotic and abiotic constrains. On the other hand, attitudes of preservation and reconstitution of the natural environment, as well as the demand for recreation and living with the acceptance of proximity to wild animals, such as the capybara in Brazil, are increasing. These modifications increase the interface of wildlife with humans and added complexity to host-pathogen relations. So, the development of certain infectious diseases already known and the emergence of new ones is predictable. In this context, vectors like ticks, and a specific host, the dog, stands as an important bridge of pathogens from natural areas to the men. It should be noted that rickettsia, intracellular bacteria, are the principal zoonotic agents transmitted by ticks in Brazil. In this work, we studies Rickettsia species in ticks from the environment and from dogs of rural proprieties surrounding the Pau Furado’s State Park, Araguari and Uberlândia, Minas Gerais, a nature reserve of Cerrado. On the whole 167 ticks were collected from dogs of two species: Rhipicephalus sanguineus e Amblyomma sculptum. An infestation prevalence of 78.6%, medium infestation intensity of 14.9 and average abundance of 11.7 was observed for R. sanguineus and of, respectively 14.3%, 1.5 and 0.2 for A. sculptum on dogs. In the environment 42 ticks from the species Amblyomma sculptum e Amblyomma dubitatum were collected. The search of Rickettsia sp. DNA was done in 58 tick samples and two samples (one larva Amblyomma spp. pools and one nymph of A. dubitatum) were positive to Rickettsia bellii and one sample (larva Amblyomma spp. pools) amplified for the OmpA gene. Of 12 samples of dogs serum, nine (75%) showed sororreactivity for at least one Rickettsia species, of these, six (66.7%) reacted R. rhipicephali, and from these two (33.3%) showed titles ≥1:1.024. The sororreactivity for R. rickettsii was observed in three (33.3%) dogs, and from these one (33,3%) showed title ≥1:1.024.