Genetic identification of a rabies virus from an insectivorous bat in an urban area of Rio Grande do Sul, Brazil

Abstract

In Latin America, hematophagous bats are the main reservoirs of rabies virus (RABV) to livestock, to other mammals and, occasionally, to human. Nonetheless, reports of exposure of human and pets to RABV upon aggression by non-hematophagous bats are increasing, possibly facilitated by the synanthropic habits of these bats. We, herein, report the detection and genetic identification of a RABV recovered from an insectivorous bat found sick in a student housing building at the Federal University of Santa Maria, Southern Brazil. Taxonomic characterization identified the captured bat as a member of the genus Nyctinomops, family Molossidae, the group of insectivorous bats. Brain fragments of the bat were positive for RABV antigens by fluorescent antibody test (FAT) and for sequences of the nucleoprotein (N) gene by RT-PCR. The N amplicon was submitted to nucleotide sequencing and analysis, showing that the consensus sequences (SV 33/19) had high identity with RABV sequences of insectivorous bats deposited in GenBank. At phylogenetic tree, the N gene sequences of SV 33/19 clustered with RABV recovered from Nyctinomops laticaudatus, Molossus molossus, and Tadarida lauticaudata bats, and a part of RABV variant 3, 4, and 6, that correspond to Desmodus rotundus, Tadarida brasiliensis, and Lasiurus cinereus, respectively. Although no direct human or domestic animal exposure has been reported, this case strengthens the need for a continuous rabies vaccination in pets in the surrounding areas, since non-hematophagous bats may serve as source of infection for these animals. These findings also call attention for continuous monitoring of populations of synanthropic bats to avoid/prevent human exposure.