Molecular epidemiology of rabies virus strains isolated from wild canids in Northeastern Brazil

Rabies in wild canids in Northeastern Brazil is frequent and has been reported for some time, with episodes of rabies transmission from these animals to humans also reported. In this study, we analyzed the antigenic and genetic profiles of the rabies virus nucleoprotein gene, isolated from 20 samples taken from domestic animals and wild canids located in the Northeastern region of Brazil. All viruses isolated from domestic animals (dogs and cats) belonged to the antigenic variant 2 (AgV2). Among the wild animal samples, only four were AgV2, and nine showed a divergent antigenic profile. Phylogenetic analysis revealed two Brazilian clusters. Cluster 1 (Brazilian domestic carnivore-related strains) showed two subclusters, called 1A and 1B, and cluster 2 (Brazilian wild canid-related strains) also showed two subclusters, called 2A and 2B. The majority of the samples with divergent antigenic strains segregated into subcluster 2A. The intracluster identity of cluster 1 was 95.6% and that of cluster 2, 92.4%. When clusters 1 and 2 were compared, an identity of 88.6% was found. The genetic analysis of wild canid samples performed in this study indicates that there are two distinct rabies cycles among canids in Brazil, one represented by domestic canids and the other by wild canids. This study shows that the virus samples isolated in Northeastern Brazil are region and species-specific.

Phylogeny of rabies virus identified in a cat closely related to vampire bat rabies based on the nucleoprotein gene

Rabies-infected bats are preyed upon by dogs and cats and the transmission of vírus from bats to domestic animais has been reported. It is expected that bat-related virus variants might be found with higher frequency in dogs and cats living in urban areas where the terrestrial cycle has been controlled. This article reports the genetic characterization of one sample of rabies virus from a cat that had contact with a bat on the border of São Paulo city. The sample was genetically typed as variant 3, associated with Desmodus rotundus, suggesting that bats and their rabies virus variants must from now on be considered in the epidemiology of rabies of urban domestic animais and in public health policies.