Pathogenicity and antigenic characterization of a novel highly virulent lineage 3 porcine reproductive and respiratory syndrome virus 2

Yon-Yip Chan; Cheng-Yao Yang; Chuen-Fu Lin; Sheng-Yuan Wang; Wei-Hao Lin; Ming-Tang Chiou; Chao-Nan Lin

doi:10.1016/j.jmii.2024.12.003

Pathogenicity and antigenic characterization of a novel highly virulent lineage 3 porcine reproductive and respiratory syndrome virus 2

J Microbiol Immunol Infect. 2024 Dec 21:S1684-1182(24)00228-7. doi: 10.1016/j.jmii.2024.12.003. Online ahead of print.

Authors

Yon-Yip Chan¹, Cheng-Yao Yang², Chuen-Fu Lin¹, Sheng-Yuan Wang³, Wei-Hao Lin⁴, Ming-Tang Chiou⁵, Chao-Nan Lin⁶

Affiliations

¹ Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan.
² Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung-Hsing University, Taichung, 40227, Taiwan.
³ Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan.
⁴ Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Research and Technical Center for Sustainable and Intelligent Swine Production, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan.
⁵ Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Research and Technical Center for Sustainable and Intelligent Swine Production, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan. Electronic address: mtchiou@mail.npust.edu.tw.
⁶ Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan; Research and Technical Center for Sustainable and Intelligent Swine Production, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan. Electronic address: cnlin6@mail.npust.edu.tw.

PMID: 39721904
DOI: 10.1016/j.jmii.2024.12.003

Abstract

Background/purpose: Porcine reproductive and respiratory syndrome virus (PRRSV) is a pathogen with a negative economic impact on the global swine industry. In 2019, a suspected highly pathogenic strain, NPUST-108-929/2019 (108-929), was isolated from a pig farm in Pingtung with an outbreak of high mortality and analyzed. The characteristics of PRRSV 108-929 have barely been studied.

Methods: This study was to evaluate pathogenicity through animal challenge experiments using PRRSV 108-929 and antigenic characterization of this novel PRRSV.

Results: This PRRSV strain is PRRSV 2, belonging to lineage 3 based on open reading frame 5 sequence analysis. Four putative N-linked glycosylation sites (N32, N35, N44 and N51) are located on glycoprotein 5. Experimental results revealed that high fever occurred at 3 days postinoculation (dpi) in the high-titer inoculation (HIN) group (2 × 10⁴ TCID₅₀/mL), 8 dpi in the high-titer contact (HC) group, 4 dpi in the low-titer inoculation (LIN) group (2 × 10³ TCID₅₀/mL) and 9 dpi in the low-titer contact (LC) group. All pigs in each PRRSV 108-929 challenge and contact group showed severe clinical signs, such as high fever (>40.5 °C) and significant weight loss. Deaths occurred only in the HIN group; the survival rate was 60 %. All the piglets except the control group piglets showed high viremia titers (6.04-8.28 log¹⁰ copies/μL).

Conclusion: The pathogenic characteristics of PRRSV 108-929 suggest that it is a highly virulent PRRSV strain at both the farm and laboratory levels.

Keywords: Animal challenge; PRRSV 2; Pathogenicity; Taiwan; Virulent.