The Emergence and Pathogenesis of Recombinant Viruses Associated with NADC34-like Strains and the Predominant Circulating Strains of Porcine Reproductive and Respiratory Syndrome Virus in Southern China

Xindong Wang; Kang Zhang; Qingrong Mo; Guochang Chen; Jing Lv; Jing Huang; Yanli Pang; Hao Wang; Wenbo Liu; Kai Huang; Xiangling Min; Tongwei Ren; Kang Ouyang; Ying Chen; Weijian Huang; Zuzhang Wei

doi:10.3390/v14081695

The Emergence and Pathogenesis of Recombinant Viruses Associated with NADC34-like Strains and the Predominant Circulating Strains of Porcine Reproductive and Respiratory Syndrome Virus in Southern China

Viruses. 2022 Jul 31;14(8):1695. doi: 10.3390/v14081695.

Authors

Xindong Wang¹, Kang Zhang¹, Qingrong Mo¹, Guochang Chen¹, Jing Lv¹, Jing Huang¹, Yanli Pang¹, Hao Wang¹, Wenbo Liu¹, Kai Huang¹, Xiangling Min¹, Tongwei Ren¹, Kang Ouyang¹, Ying Chen¹, Weijian Huang¹, Zuzhang Wei¹

Affiliation

¹ College of Animal Science and Technology, Guangxi University, No.100 Daxue Road, Nanning 530005, China.

Abstract

Since its recent appearance in China, the NADC30-like strains of porcine reproductive and respiratory syndrome virus 2 (PRRSV-2) have caused an expanding epidemic, and this has further expanded the genetic diversity of PRRSV. In this study, three NADC30-like strains-GXFCG20210401, GXQZ20210403 and GXNN20210506-were isolated from pig serum samples obtained in Guangxi, and their genomes were sequenced. A comparative analysis of the whole genomes showed that the three strains were most similar to NADC30 (88.3-88.7%). In particular, the non-structural protein coding regions (nsp1, nsp4-5, nsp7-8 and nsp9) showed the highest similarities to JXA1, and the ORF2a-ORF5 regions showed the highest similarities to NADC34. The three strains had same discontinuous deletions of 111+1+19 amino acids in the nsp2 region, which were similar to the NADC30-like strains. Phylogenetic tree analysis based on the ORF5 gene showed that the three PRRSV isolates were divided into lineage 1.5 along with the representative NADC34-like strains, but they were classified as NADC30-like strains with respect to the whole genome and nsp2 evolutionary trees. Recombinant analysis revealed complex recombination patterns in the genomes of the three strains, which likely originated from multiple recombination events among JXA1-like, NADC30-like and NADC34-like strains. The results from animal experiments showed that the GXQZ20210403 strain was 20% lethal to piglets and caused more severe clinical reactions than GXFCG20210401, and both recombinant strains were similar in terms of pathogenicity to the previously reported NADC34 strains. This study demonstrates that NADC34-like strains of PRRSV have been circulating in the southern provinces of China and have exchanged genomes with several other indigenous strains. In addition, differences in recombination patterns may cause different clinical pathogenicity and indicate the importance of the surveillance and preventive control of recombinant strains.

Keywords: NADC34-like; genetic evolution; pathogenicity; porcine reproductive and respiratory syndrome virus; recombination.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
China / epidemiology
Genetic Variation
Genome, Viral
Orthopoxvirus*
Phylogeny
Porcine Reproductive and Respiratory Syndrome* / epidemiology
Porcine respiratory and reproductive syndrome virus* / genetics
Recombination, Genetic
Swine

Grants and funding

This research was funded by the National Natural Science Foundation of China (No. 32172889) and the Natural Science Foundation of Guangxi Province (No. 2018GXNSFDA281021).