Investigação de flavivírus em morcegos no município de Caxias- MA

Abstract

In Brazil, arboviruses are widely distributed due to suitable ecological conditions. Among the various arboviruses that Brazil has faced, dengue, zika and yellow fever stand out. The mosquito Aedes aegypti Linnaeus (1762) (Diptera: Culicidae) is the vector of these arboviruses, and these arboviruses belong to the genus Flavivirus, of the Flaviviridae family. The main replicative cycle of these viruses involves only humans and mosquitoes in large urban centers. However, another cycle involving bats and flaviviruses has been much discussed. Several studies, using the reverse transcription technique followed by polymerase chain reaction (RT-PCR), have shown the presence of the Flavivirus genus in bats, however, in Brazil few studies have investigated the presence of flavivirus in bats. The present research, in addition to producing a rich knowledge about the biodiversity of bats in Maranhão, focuses on the monitoring of Flavivirus in bats in the municipality of Caxias (MA). Thus, that work aims to investigate the potential of bats in the city of Caxias as hosts of Flavivirus. To this end, bats were captured in the municipality of Caxias, in the day and night shifts. Blood, liver, intestine, kidney and heart samples were collected aseptically and stored in tubes containing RNAlater and conditioned at -80 °C for later use. The morphological identification of the specimens was made with the aid of specialized bibliography. The identification of flaviviruses in bat samples was performed with the extraction of total RNA, following the SV Total RNA Isolation System DA Promega Corporation protocol, RT-PCR followed by nested-PCR from specific primers of each serotype to characterize the type of infecting virus. During the nine expeditions, in the years 2019, 2020 and 2021, 77 bat specimens were captured in the municipality of Caxias and were identified within four families and ten species, with the Molossidae family being the most abundant with 64.93% of the specimens sampled. Molossus molossus was the most abundant species with 42.86% of this genus. Of the biological samples used, 23 samples were positive for the detection of flavivirus viral RNA being found in the species Carollia perspicillata, Glossophaga soricina, Pteronotus gymnonotus, Anoura caudifer, Rhynchonycteris naso, Phyllostomus hastus, Molossus molossus more precisely for the dengue viral genome being serotype 2 (DENV-2) the most detected. However, it is important not to forget the essential role that bats play in the ecosystem. Viral detection in bats does not necessarily imply that they are hosts of the viruses, but rather that they may be in possible contact with the infectious agents. Finally, research should be continued, for constant monitoring, as flaviviruses of medical importance represent a significant global challenge due to the recurrent epidemics that occur in several regions of the world.