Detecção de hemopatógenos e seus vetores na população de cães no município de Itabirito – MG

Abstract

Some tickborne diseases play an important role in veterinary medicine in addition to the zoonotic potential of some of these diseases. This study aimed to detect the species of ticks present in dogs from Itabirito, Minas Gerais, a transition area of Atlantic forest and cerrado, connecting this with health data of these animals, and detect hemoparasites in these hosts. Blood samples and ticks were collected from 100 dogs. The origin of these animals were 9 domiciliated dogs which were sent to the castration program, 20 stray dogs rescue and sent to the municipal kennel of the county, and 71 domiciliated dogs in Portões, a neighborhood of Itabirito. The samples from these dogs were collected for convenience sampling. Also, were collected some health information about these dogs with a questionnaire direct to their tutors. In order to assess whether there was a statistical association between the data extract from questionnaire and tick infestation the chi-square test was applied with 5% confidence. The study collections were performed between October 2017 and May 2018. For the identification of the collected ticks, taxonomic keys of ixodids were used. For the detection of hemopathogens of the genera Ehrlichia and Anaplasma, molecular analysis was performed on all blood samples, using the nested polymerase chain reaction (nPCR) and for the genera Hepatozoon, Babesia and Rangelia using the polymerase chain reaction (PCR). Nucleotide sequencing was performed to specifically identify the etiologic agents found. In addition, the diagnosis of Ehrlichia canis and Anaplasma phagocytophilum was carried out through the indirect immunofluorescence reaction (RIFI), this method not being used for other species of hemopathogens. Were collected 210 tick specimens. From these, were found: 47 females, 68 males, 62 nymphs and three larvaes of the Rhipicephalus sanguineus s. l; three males and five females of the Amblyomma aureolatum; eight nymphs, four females and eight males of Amblyomma sculptum; and two females of Rhipicephalus microplus. The parasitism occurred in 3/9 (33.33%) refered for surgical sterilization, 11/20 (55%) dogs from capture – these both group of animals were analysed in municipality kennel - and 48/71 (67.60%) dogs examined in Portões neighborhood. About the 78 dogs health data, it was reported that 60.26% of the dogs walking with the tutors; however only 6.08% of these tutors always use leash and guide. Regarding the confinement of these animals, 43.59% of the dogs do not have any physical block barrier and 5.12% live in contact with forest area. Besides, other data reveal that 75 dogs had contact with others animals, as follow: 29 with others dogs; 28 with others domestic animals; and 18 with domestic and wild animals. There was no statitical significant difference in the prevalence of infestation between these groups of animals. The tick infestation control was performed in 57 dogs, and the most common method used was the bath with antiparasitic products. In general, the treatments of dogs did not follow any veterinary professional instructions and, it has been shown that dogs treated with antiparasitic drugs or other methods for tick control did not differ statistically in infestation prevalence when compared with the group without any treatment. In the molecular analysis 17% of samples were amplified using primers for 16S rRNA belongs to the granulocytic and trombocytic Anaplasmataceae members. For SSU rDNA gene from Piroplasm 9% of samples were amplified; 7% samples were amplified for the 18s rRNA gene for Hepatozoon spp.; 5% of samples were amplified for dsb gene from Ehrlichia spp., and 1% of samples were amplified using msp4 gene as target for A. phagocytophilum. By the serological diagnosis using IFAT were detected 19% reactive samples for E. canis in 1:40 dilution and 6% reactive samples for A. phagocytophilum in the following dilutions: 1 dog - 1:40; 2 dogs – 1:80; 2 dogs – 1:160; and 1 dog – 1:320. In conclusion, there was the circulation of tickborne diseases in this population of dogs in Itabirito – MG and these dogs have contact with wild and domestic species which predisposes the human population have contact with ticks from wild areas and possible to hemopathogens carried by these ticks. Future studies are need in order to better define the R. vitalli and A. phagocytophilum circulation. Beyond of these pathogens researched in this work, it will be necessary an investigation about Rickettsia genus organisms, because they represent great importance in veterinary medicine and public health.