Detecção molecular de Piroplasmideos e Anaplasmataceae sp. em bubalinos (Bubalus bubalis) no Baixo Amazonas

Abstract

Buffaloes (Bubalus bubalis) are well adapted in the Amazon, especially in the state of Pará, however information on health aspects of the herds is scarce. Diseases transmitted by ticks such as Piroplasmosis and Anaplasmosis cause important losses in cattle herds, however there is still a debate about the degree of susceptibility of buffaloes to these diseases as well as information on the characterization of these pathogens that infect buffaloes is lacking. The present study aimed to determine the prevalence and possible risk factors associated with infection by Piroplasmid and Anaplasma sp. in buffaloes in the Lower Amazon region and to molecularly characterize these pathogens infecting buffaloes in the region. A cross-sectional study was carried out considering two sampling levels (farm and animal) and 621 samples ofwhole blood ofbuffaloes were obtained from 60 properties in the region, including floodplain and dry land areas. Ectoparasites present in buffaloes were collected and an epidemiological questionnaire was applied. Whole blood and ectoparasite samples were subjected to DNA extraction and polymerase chain reaction (PCR) analysis using primers (BAB2), BAB-143-167 (5'- CCGTGCTAATTGTAGGGCTAATACA-3') sense and BAB-694- 667 (5'- GCACTCTARTCTCAAAG-3) antisense that amplifies a 551 bp fragment of the 18S rRNA gene ofthe Piroplasmid order and the EHR16SD rRNA primer that amplifies a 344 bp fragment of the 16S rRNA gene from almost all members of the Anaplasmatacea family. PCR positive samples were submitted to BLAST sequencing for characterization and species identification analysis. The results obtained showed a prevalence of2.09% of Piroplasma sp. The analysis of risk factors among animals showed significant results in factors related to age group, location of the property, performance of ectoparasite control and whether there was the presence of wild animals. In the analysis of Risk Factors between farms, the buffaloes sampled in areas of dryland had 4.5 times (1 -19, 95% CI) greater risk of being infected with Piroplasma compared to animals kept in wetland. Among the 13 positive animals, the sequencing result allowed the identificationof five samples at the species level, not being possible to identify all the positive samples.Five buffaloes were positive to Theileria, with four buffaloes infected with Theileria buffeli and one infected with Theileria Ocidentalis. Regarding ectoparasites, of the 95 collected, eight ticks were positive in PCR for Piroplasmid, but no sample was successful in sequencing and identifying the species. Regarding Anaplasmataceae, only two animals were positive, so the prevalence was only 0.32% (0.04-1.16, 95% CI), thus, due to the reduced number of positive animals, the analysis of factors risk is considered irrelevant. The sequencing of positive animals revealed infection by Anaplasma platys with 99.42% similarity and Anaplasma phagocytophilum with 98.49% similarity. One positive buffalo had lice, however none had ticks. The present study identified for the first time Theileria buffeli and Theileria Ocidentalis, Anaplasma platys and Anaplasma phagocytophilum in buffaloes in the Lower Amazon region.