Prospecção de flavivírus em culicídeos e pequenos mamíferos, em Minas Gerais, Brasil

Abstract

Brazil is a tropical country of vast territory, with more than one third covered with tropical forests and ecosystems creating ideal conditions for the existence of many arboviruses that are maintained in a variety of zoonotic cycles. Within this scenario, Minas Gerais presents three of the most important biomes of Brazil, the Atlantic Forest that is considered hotspot of biodiversity. These factors plus the climatic differences, the great latitudinal range and the diversity of vegetation favor the occurrence of areas with high diversity index and endemism of mammals. Given this context, this work aims to prospect flaviviruses in mosquitoes and small mammals, in Minas Gerais, Brazil. Pools of mosquitoes collected in Montes Claros, in 2012, were submitted to RNA extraction and tested by RT -PCR for the presence of flaviviruses. A collection of small mammals (Collection- ECOVIR) collected in Rio Pomba, MG, in 2012 and 2013 was also analyzed in this work. A total of 115 serum samples and 54 liver samples were submited to RNA extraction, followed by cDNA synthesis and they were tested for the presence of flavivirus by qPCR technique. A total of 96 mosquito pools was tested and one pool of Aedes aegypti presented an amplicon that could represent a DENV-1 infection. Subsequently, 69 pools were tested for YFV, SLEV and ROCV and a pool of A. scapularis presented a DNA amplicon fragment with expected size for ROCV and it was positive in qPCR using primers Flavi-1, indicating the circulation flavivirus in Aedes scapularis in the urban environment, in Montes Claros. A sample of a rodent Calomys sp. was detected as naturally infected with flaviviruses (possibly SLEV, DENV-1, DENV -3 and DENV-4), indicating that rodents may be part of the maintenance chain and/or flavivirus transmission in nature, Brazil. This rodent sample was collected in the pasture area that could be considered a transition area between the wild and peridomestic environments.