Complete genome characterization of porcine circovirus 3 recovered from wild boars in Southern Brazil

In the present study, the complete nucleotide sequence of porcine circovirus 3 (PCV3) recovered from wild boars lymph nodes is described. The full genome was named PCV3‐wb/Br/RS and comprises 2,000 nucleotides with two open reading frames (ORFs) with a stem‐loop motif in intergenic region. The ORFs are oriented in opposite directions and encode the putative capsid (Cap) and replicase (Rep) proteins. Based on amino acid motif analysis, PCV3‐wb/Br/RS as well as most of the sequences from wild boars are classified as PCV3b. Phylogenetic analysis including 97 PCV3 sequences available in databases showed that the PCV3‐wb/Br/RS genome is more closely related to genomes recovered in Spain, China, Germany and Denmark. Phylogenetic inferences among PCV3‐wb/Br/RS and other circoviruses confirmed that these seem to have a most recent common ancestor with bat‐associated circoviruses. In addition, PCV3 infection was investigated by real‐time PCR in a cohort of 80 wild boars in Southern Brazil. A total of 29 animals (36.3%) were PCV3‐positive leading the conclusion that PCV3 is circulating in the wild boar population in Southern Brazil. The role played by PCV3‐like infections in wild boars and the risk these could pose to commercial swine production within that region remains to be further investigated.