Genetic Characterization of Porcine Circovirus 3 Strains Circulating in Sardinian Pigs and Wild Boars

Abstract

Porcine circovirus 3 (PCV3) is a recently discovered member of the Circoviridae family. So far, its presence has been reported in North America, Asia, South America, and Europe. In this study, blood and tissue samples from 189 Sardinian suids (34 domestic pigs, 115 feral free ranging pigs, and 39 wild boars) were used to genetically characterize the PCV3 strains from Sardinia. PCV3 infection in the animals was confirmed by real time PCR. The detection rate in the three groups analyzed was l7.64% in domestic pigs, 77.39% in free ranging pigs, and 61.54% in wild boars. Moreover, our results showed that co-infection of PCV3 with other viruses is quite a common occurrence. Molecular characterization of Sardinian PCV3 strains was performed by sequencing 6 complete genomes and 12 complete cap genes. Our results revealed that there is a high similarity between our strains and those identified in different countries, confirming the genetic stability of PCV3 regardless of geographical origin. Haplotype network analysis revealed the presence of 6 whole genomes or 12 unique ORF2 haplotypes and a nonsynonymous mutation in ORF2 that leads to an R14K amino acid substitution. Phylogenetic analysis of whole genome and ORF2 was also conducted. The Sardinian strains were allocated in three different clusters of phylogenetic trees of both complete genome and ORF2. With this study, we have provided a snapshot of PCV3 circulation in Sardinia. Our findings might help to achieve a deeper understanding of this emerging porcine virus.

Analyses of the Impact of Immunosuppressive Cytokines on Porcine Macrophage Responses and Susceptibility to Infection to African Swine Fever Viruses

“…The presence of PRRSV or M. hyopneumoniae genome was subsequently screened using commercial real-time PCR kits, LSI VetMAX™ PRRSV EU/NA and VetMAX™-Plus qPCR Master Mix (both Thermo Fisher Scientific), respectively. The presence of PCV2 was instead evaluated by qualitative real-time PCR, as we previously described [44], using forward primer 5 -TGGCCCGCAGTATTCTGATT-3 and reverse primer 5 -CAGCTGGGACAGCAGTTGAG-3 [45]. Samples with Ct values less than 40 were considered positive [44].…”

Recent Progress on Epidemiology and Pathobiology of Porcine Circovirus 3

“…It is worth noting that the co-infections of PCV3 with PCV2 and/or PPV were common in both domestic and wild boars [70]. Dei et al evaluated blood and tissue samples from 189 Sardinian suids (34 domestic pigs, 115 feral free-ranging pigs, and 39 wild boars) and found that the infection rates of PCV3 in the three groups were 17.64%, 77.39%, and 61.54%, respectively [70]. Moreover, whether co-infection is related to more severe clinical symptoms needs to be further clarified.…”

Detection of Porcine circovirus 3 from captured wild boars in Korea

“…Complete genome sequence of PCV3 isolate WB‐33 was compared with 83 complete genome sequences of PCV3 obtained from pigs and wild boars retrieved from GenBank (Figure 3c). PCV3 phylogenetic analysis showed that the PCV3 isolate WB‐33 is closely related to PCV3 genomes recovered from wild boars in Brazil (Varela et al., 2020), Italy (Dei Giudici et al., 2020) and Spain (Klaumann et al., 2019) and sequences recovered from domestic pigs in China, Denmark, Germany and Italy.…”