Porcine circovirus 2 and 3 in wild boars in Southern Brazil

Ana Carolina Dal Santo,Isabella Mazzocato Dazzi,Samay Zillmann Rocha Costa,João Rogério Centenaro,Mathias Martins,Leticia Trevisan Gressler

doi:10.1590/0103-8478cr20210209

Abstract

ABSTRACT: Porcine circovirus 2 (PCV2) has a considerable economic impact on the pork industry worldwide for more than two decades. In 2016, a new circovirus, porcine circovirus 3 (PCV3), was described; since then, it has been reported to be associated with diseased or even in clinically healthy swine in several countries. Considering the importance of wild boars as reservoirs of swine pathogens and the extensive distribution of these animals in Rio Grande do Sul and throughout the national territory, we searched for PCV2 and PCV3 in twenty-six wild boars coupled with necropsy and histologic examination of the sampled animals. Using PCR, 182 tissue samples were analyzed, including the heart, kidneys, liver, lung, lymph nodes, spleen, and tonsils. PCV2 and PCV3 were detected in 57.7% (15/26) and 15.4% (4/26) of wild boars, respectively. Furthermore, co-infection with PCV2 and PCV3 was detected in one of these animals, with PCV2 or PCV3 DNA detection in multiple organs. Histological examination showed mild to moderate and multifocal lymphoplasmacytic interstitial nephritis distributed randomly throughout the renal cortex, apparently unrelated to PCV2 or PCV3 detection. The wild boar population in Brazil is extensive, indicating the presence of a larger number of swine pathogen hosts. In the present study, more than half of the wild boars harbored PCV2; and although less frequently, PCV3 was also detected. Therefore, free-living wild boars can serve as reservoirs of swine circoviruses in southern Brazil.

Highlights

Wild boars (Sus scrofa scrofa) are present in 22 of the 27 Brazilian States, including Rio Grande do Sul, the southernmost state of Brazil (BRASIL, 2019)
porcine circovirus 3 (PCV3) has been associated with several pathological disorders, such as stillbirths (ARRUDA et al, 2019; DAL SANTO et al, 2020; SAPORITI et al, 2020), cardiac and multi-systemic inflammation (PHAN et al, 2016; TEMEEYASEN et al, 2021), porcine dermatitis and nephropathy syndrome (PDNS)-like disease, and reproductive failure (ARRUDA et al, 2019; DAL SANTO et al, 2020; PALINSKI et al, 2017), and can even be reported in healthy domestic pigs and wild boars (FRANZO et al, 2018; STADEJEK et al, 2017)
The representative electrophoresis picture showing the positive amplification of Porcine circovirus 2 (PCV2) and PCV3 alongside their respective molecular weight markers is shown in the figure 2

Summary

Introduction

Wild boars (Sus scrofa scrofa) are present in 22 of the 27 Brazilian States, including Rio Grande do Sul, the southernmost state of Brazil (BRASIL, 2019) This species is susceptible to several pathogens with the potential for transmission to domestic pigs, and these animals may act as a disease reservoir (MENG; LINDSAY, 2009). PCV3 has been associated with several pathological disorders, such as stillbirths (ARRUDA et al, 2019; DAL SANTO et al, 2020; SAPORITI et al, 2020), cardiac and multi-systemic inflammation (PHAN et al, 2016; TEMEEYASEN et al, 2021), porcine dermatitis and nephropathy syndrome (PDNS)-like disease, and reproductive failure (ARRUDA et al, 2019; DAL SANTO et al, 2020; PALINSKI et al, 2017), and can even be reported in healthy domestic pigs and wild boars (FRANZO et al, 2018; STADEJEK et al, 2017). Another study performed the first isolation of PCV3 from perinatal and reproductive failure cases in the United States and characterized the infection by experimental inoculation of PCV3 isolate in cesarean-derived, colostrum-deprived pigs (MORADÍAZ et al, 2020)

Methods

Results

Conclusion