Characterization of a vaccinia-like virus isolated in a Brazilian forest.

The SPAn232 virus (SPAnv) was isolated from sentinel mice in the forest of Cotia, São Paulo, Brazil. It was grouped originally as a Cotia virus (CV) sample due to serological cross-reaction with the latter. However, SPAnv presented genetic characteristics that differed from CV and indicated that SPAnv is a member of the vaccinia virus (VV) subgroup. SPAnv showed a HindIII-digested DNA pattern similar to those of the WR and Lister strains of VV. Also, SPAnv presented genes homologous to the vaccinia growth factor, thymidine kinase and A-type inclusion (ATI) genes from VV. RFLP analysis of the SPAnv ATI homologous gene indicated that the virus belongs to the VV group. Nucleotide sequences from SPAnv genes showed up to 99% similarity with the same genes from VV. Such a relationship was confirmed visually through the drawing of phylogenetic trees. The results point out the occurrence of a VV strain that is possibly in active circulation in the forests of Southeast Brazil.