Detection of rabies virus RNA isolated from several species of animals in Brazil by RT-PCR.

This research studies how the rabies virus detected in various animal species in Brazil, including humans. The research used different testing methods and discovered a genetic difference in the Brazilian rabies virus.

Research Objectives and Methods

• The main aim of this research was to detect the presence of the rabies virus in brain samples collected from several species of animals in different regions of Brazil. This was done using various tests including the Fluorescent Antibody Test (FAT), the Mouse Inoculation Test (MIT), and the Reverse Transcription Polymerase Chain Reaction (RT-PCR).
• The FAT and MIT were initially used to ascertain the presence of the rabies virus, while the RT-PCR was used for further testing and confirmation.
• The RT-PCR used two primer sets, namely P1/P2 and RHNI/RHNS3, to amplify full or partial regions on the nucleoprotein gene of the rabies virus.

Research Findings

• The research ascertained the presence of the rabies virus in all tested animal species through the FAT and MIT tests.
• When retested using the RT-PCR method with the RHNI/RHNS3 primer set, brain samples from five vampire bats, 13 cattle, one horse, and one sheep did not yield PCR products. This indicates that the primer set RHNI/RHNS3 was unsuccessful in detecting the presence of the rabies virus in these samples.
• However, all samples successfully yielded PCR products when the P1/P2 primer set was used, indicating a successful detection of the rabies virus through this method.
• The outcomes suggest that the Brazilian rabies virus may be divided into two main populations according to genetic difference. This division could have stemmed from the variation in the amplification success of the two primer sets used in the RT-PCR method.