Estudo molecular e análise filogenética do segmento-7 do vírus da língua azul (orbivirus caerulinguae) isolados de cervídeos da espécie mazama nana

Abstract

The Cervidae family, comprising 56 globally distributed species, includes six genera of deer in Latin America, represented by 17 species, seven of which are found in Brazil. Among these, Mazama nana and Blastocerus dichotomus are classified as vulnerable species, facing extinction risks due to hunting, habitat destruction, and infectious and non-infectious diseases. The population decline of these deer can be attributed to factors such as viral diseases, particularly hemorrhagic diseases caused by viruses from the Sedoreoviridae family, such as Orbivirus caerulinguae (Bluetongue Virus - BTV) and Orbivirus ruminantium (Epizootic Hemorrhagic Disease Virus - EHDV), which are transmitted by Culicoides midges. At ITAIPU Binacional, the Bela Vista Biological Refuge (RBV) plays a fundamental role in the conservation of native Brazilian wildlife, including Mazama nana and Blastocerus dichotomus. In this location, different BTV serotypes have been identified, with clinical cases characterized by acute and fatal conditions. This study aims to advance the understanding of the epidemiology of these viruses at RBV, focusing on the molecular analysis of segment 7 (Seg-7) of Orbivirus caerulinguae, which encodes the structural protein VP7. This protein is considered the most immunodominant and is correlated with viral replication in the vector. The role of this protein in viral replication within the vector is associated with the geographic origin of the virus, as the distribution of Culicoides species varies geographically. Thus, Seg-7 analysis can help trace possible routes of introduction and maintenance of BTV at RBV - ITAIPU, as well as in Brazil.