Detecção molecular de Ehrlichia canis em carrapatos Rhipicephalus sanguineus (s.l.) de cães e ambiente domiciliar em Cuiabá, MT

Abstract

Since the central region of Brazil is characterized as an endemic area for ehrlichiosis, the present study aims to determine the prevalence rates of infection in dogs and their R. sanguineus ticks, collected from the same environment. Serum samples and genomic DNA from the blood of 20 dogs and 299 ticks were carried out for IFA and PCR assays in order to detect antibodies and DNA of E. canis. From the total, 9 (45%) were seropositive for E. canis with titers ranging from 80 to 10240 and 6 dogs (30%) were positive for Ehrlichia spp. by PCR. Five free-living ticks were positive (2.89%; 95% confidence interval: 0.94% 6.62%) as well as positive ticks fixed on dogs were 6 (4.76%; 95% CI: 1.77 – 10.0%). A similar rate of infection was found between both group (P>0.05). Partial dsb DNA sequences of 2 samples from ticks were identical to each other and 100% (350/350) identical to E. canis. In spite of high serological and molecular rates of canine ehrlichiosis in Cuiabá, prevalence of infected ticks was much lower than found in dogs. In the other side, adult ticks may remain infective much longer to guarantee their infestation and infection to susceptible dogs.