Detection and sequencing of porcine circovirus 3 in commercially sourced laboratory mice.

Shouchuan Jiang,Yufeng Li,Tianhao Chang,Jiahui An,Nini Zhou

doi:10.1002/vms3.144

Shouchuan Jiang, Yufeng Li + Show 3 more

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https://doi.org/10.1002/vms3.144

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Abstract

Porcine circovirus 3 (PCV3), a recently discovered virus, has spread widely in pigs throughout the world. In order to investigate the possibility of mice used to study the infection of PCV3, commercially sourced Balb/C and ICR mice were screened for PCV3 infection. Blood samples were collected from 20 mice (10 each of Balb/c and ICR), DNA was extracted, and subjected to PCR with PCV3 specific primers. We found all 20 serum samples tested positive for PCV3 DNA. From four mice, the complete genomes of PCV3 were amplified and sequenced, and a phylogenetic tree was constructed. The results showed that the amplified genome was 2000 bp, and sequence comparison showed that the homology of the complete genome and ORF2 gene with those of porcine PCV3 are 97.9%–98.8% and 96.9%–98.3%, respectively. Amino acids alignment results showed that the Cap protein of the mouse PCV3 isolates share 90.7%–96.3% amino acid homology with that of the references strains derived from pigs. Phylogenetic analysis based on ORF2 sequences showed that all PCV3 strains clustered together and were clearly separate from other circovirus species. We detected PCV3 in experimental mice in China for the first time, which is an opportunity to use mice to study the infection of PCV3 and a potential hazard to swine industry.

Highlights

Porcine circoviruses are single-stranded circular DNA viruses with a non-enveloped icosahedral capsid
Amino acid alignment results showed that the Porcine circovirus 3 (PCV3) capsid protein (Cap) proteins from the four mice share 90.7%–96.3% homology with PCV3 Cap proteins from the references strains
We found point substitutions in ICR mice are higher than that of in Balb/c mice, which is obviously different from that observed in PCV3 derived from pigs

Summary

Introduction

Porcine circoviruses (family Circoviridae, genus Circovirus) are single-stranded circular DNA viruses with a non-enveloped icosahedral capsid. They are among the simplest of viruses, consisting of capsid protein and genome, and are one of the smallest DNA viruses know to infect animals (Palinski et al 2017). PCV1 is nonpathogenic to pigs, but PCV2 is associated with postweaning multisystemic wasting syndrome (PMWS), porcine dermatitis and nephritis syndrome (PDNS), proliferative necrosis pneumonia (PNP), porcine respiratory syndrome (PRDC), reproductive disorders, congenital tremors, and enteritis. In 2016, a new type of porcine circovirus, PCV3, was identified from dead sows with symptoms like Porcine Dermatitis and Nephropathy Syndrome (Palinski et al 2017). The PCV3 capsid protein (Cap), is encoded by ORF2 and consists of 214 amino acids (aa) residues (Palinski et al 2017), which is 16–17 aa and 19–20 aa less than the Cap of PCV1 (230–231 aa) and PCV2 (233–234 aa), respectively

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