Genetic characterization of porcine circovirus type 2 in captive wild boars in southern Brazil.

Abstract

Porcine circovirus type 2 (PCV2) has been identified in pig population in Brazil since 2000, but scarce studies involving wild boars with PCV2 infection are reported in the country. This study aimed to perform the genetic characterization of PCV2 detected in clinically healthy captive wild boars from farms located in Southern Brazil. Bronchial and mesenteric lymph nodes from 129 clinically healthy captive wild boars were tested by nested PCR for PCV2 detection. Six out of 38 positive samples (29.5%) were submitted to a quantitative real time PCR (qPCR) and genetic sequencing. Viral load up to 1.19×109 viral DNA copies/uL was detected in lymph nodes samples by qPCR. According to the ORF2 gene sequence analysis, all PCV2 samples were classified into PCV2b genotype. Comparisons based on a 702nt region of the ORF2 of all six isolates revealed a high degree of similarity between these isolates. The ORF2 sequences characterized here share 97.1-100% of nucleotide identity and 95.7-100% of amino acid identity with other PCV2b isolated in Brazil from wild boars and feral pigs. This study reports the first detection and genetic characterization of PCV2b in captive wild boars in Brazil and provides important information on PCV2 infection in this domesticated species.