Development and application of a quadruplex real‐time PCR assay for differential detection of porcine circoviruses (PCV1 to PCV4) in Jiangsu province of China from 2016 to 2020

Abstract

Porcine circoviruses (PCVs) are circular, non-enveloped, single-stranded DNA viruses. They belongs to the genus Circovirus in the family Circoviridae (Mankertz et al., 2004). Four species of PCVs have been characterized, including PCV1, PCV2, PCV3 and PCV4 (Phan et al., 2016; Zhang et al., 2020). PCV1 is not pathogenic (Tischer et al., 1982). PCV2 is considered a causative agent of porcine circovirus-associated diseases (PCVAD) (Segales, 2012). PCV3 is associated with reproductive failure, porcine dermatitis and nephropathy syndrome (PDNS) and multi-systemic inflammation (Palinski et al., 2017;

Porcine Circovirus Type 3 Cap Inhibits Type I Interferon Induction Through Interaction With G3BP1

“…Porcine circovirus 3 (PCV3), a DNA virus, has a genome of only 2 kb in size with two main open reading frames (ORFs) encoding the replicase protein and capsid (Cap) protein (1). Currently, four types of porcine circoviruses (PCVs) are known (2). While porcine circovirus 1 (PCV1) is considered nonpathogenic to pigs (3), porcine circovirus 2 (PCV2) is the pathogen responsible for the multiple clinical manifestations of porcine circovirus-associated diseases, such as nephropathy syndrome (PDNS) and postweaning multisystemic wasting syndrome and porcine dermatitis (4)(5)(6), which threaten the global swine industry.…”

Structure, Antigenic Properties, and Highly Efficient Assembly of PCV4 Capsid Protein

“…However, there is very limited information about its epidemiology, origin, evolution, pathogenesis, and transmission in swine herds. Notably, PCV4 has been detected as coinfections with PCV2, PCV3, or both (6)(7)(8). As PCV4 may be a serious risk for swine health, a better understanding of PCV4 pathogenesis, its epidemiology, and serological surveys to determine its prevalence is urgently needed.…”

“…PCV4 is suspected to be associated with these clinical signs, which also occur in pigs infected with PCV2 or PCV3 (1). Subsequently, PCV4 infections causing clinical signs in swine were reported in Henan, Shanxi, Jiangsu, Anhui, and Guangxi provinces, China (5)(6)(7)(8), with PCV4-positive rates ranging from 5.1% (13/257) to 25.4% (16/63). Recently, PCV4 has also been detected on swine farms in Korea (9).…”

The Nucleolar Localization Signal of Porcine Circovirus Type 4 Capsid Protein Is Essential for Interaction With Serine-48 Residue of Nucleolar Phosphoprotein Nucleophosmin-1

“…Porcine circovirus type 4 is an emerging etiological agent with enormous economic loss to global pig farms, which is linked to diverse clinical symptoms, including respiratory and gastrointestinal signs and PDNS ( Zhang et al, 2019 ). Since 2019, PCV4 has been reported in about six provinces in China ( Zhang et al, 2019 ; Sun et al, 2020 ; Chen et al, 2021 ; Ha et al, 2021 ; Tian et al, 2021 ). The PCV4 genome bears two ORFs: ORF1 encoding replicase and ORF2 encoding capsid ( Zhang et al, 2019 ).…”

“…PCV4, a previously unidentified PCV, which was first detected in Hunan province, China, in 2019, was considered to be related to serious clinical signs, including respiratory distress and PDNS (Zhang et al, 2019). Since then, PCV4 has also been discovered in some other provinces in China (Sun et al, 2020;Chen et al, 2021;Ha et al, 2021;Tian et al, 2021), demonstrating that PCV4 is probably prevalent in Chinese pig farms. Additionally, PCV4 was also reported in South Korea but was not discovered in Italy and Spain (Franzo et al, 2020;Nguyen et al, 2021).…”