Molecular epidemiology of rabies virus isolated of herbivores from Brazilian Amazon

Abstract

Rabies virus samples (n = 17) isolated from bovines (n = 11), equines (n = 4) and buffalo (n = 2) from Pará State (n = 7), Tocantins (n = 6) and Rondônia (n = 4) were submitted to RT-PCR in order to obtain partial sequences of nucleoprotein (N) and glycoprotein gene (G). Nucleotide sequences were analyzed using Neighbor-Joining model, Kimura 2-parameters evolutionary model. All the 17 samples analyzed were related to cluster A, lineage associated with the hematophagous bat Desmodus rotundus. The phylogenetic analysis based on the N and G genes, suggests the presence of five sub-lineages (A1-A5), while G gene showed seven sub-lineages (A1-A7). In both phylogenies, sublineages A1 to A3 exhibit a similar composition and geographic distribution. Diverse composition of remaining groups of N and G gene is attributable to different sequences used in the alignments for each genomic region. Glycoprotein amino acid sequence showed molecular markers in sub-lineages A2, A3, A4 and A7. This information provides a better comprehension of molecular epidemiology of rabies, starting with the knowledge of viral lineages circulating in the Brazilian Amazon.Keywords: Herbivores. Nucleoprotein. Glycoprotein. Phylogeny. Rabies. ResumoAmostras do vírus da raiva (n = 17) isoladas de bovinos (n = 11), equinos (n = 4) e bubalinos (n = 2) procedentes do Pará (n = 7), Tocantins (n = 6) e Rondônia (n = 4) foram submetidas à técnica de RT-PCR para amplificação parcial dos genes da Nucleoproteína (N) e Glicoproteína (G). As sequências nucleotídicas obtidas foram analisadas pelo método de reconstrução filogenética Neighbor-Joining com o modelo evolutivo Kimura 2-parâmetros. Todas as 17 amostras pertenceram ao cluster A, que se encontrou na linhagem associado com morcego hematófago Desmodus rotundus. A análise filogenética baseada nos genes N e G, sugere a presença de cinco sublinhagens (A1-A5) e sete sublinhagens (A1-A7), respectivamente. Quando se compara ambas as filogenias, as sublinhagens A1 até A3 mostram composição e distribuição geográfica concordante, já a diversidade observada na composição das sublinhagens restantes é atribuída ao uso de sequências de diferentes alinhamentos. A glicoproteína mostrou marcadores moleculares nas sublinhagens A2, A3, A4 e A7, o que fornece elementos para melhor compreensão da epidemiologia molecular da raiva das linhagens circulantes na Amazônia Brasileira. Palavras-chave:Herbívoros.

Comparison of 4 laboratory tests for the detection of bovine rabies viral infection in Paraguay: fluorescent antibody test, rapid detection test, histologic lesions, and RT-PCR

“…23 One of the possible causes of the disparity in the results between the 2 genes could be that the gene that encodes the G protein is related to the ligation of cell receptors and is targeted for the neutralization of the virus; therefore, it has a higher rate of mutation, and divergences in the sites of annealing of the primers could be a probable cause of nonamplification of the samples that amplify the G gene. 15,27 Although molecular techniques have great advantages, their routine use presents some difficulties, such as the loss of integrity of viral RNA due to freezing and thawing, as well as the need for storage at −80°C. 1 The samples that we analyzed were frozen and thawed for processing; therefore, this could be a factor in RNA degradation.…”