A NADC30-like PRRSV causes serious intestinal infections and tropism in piglets

• Main Authors: Xin Ma, PeiXin Wang, RiTeng Zhang, Yongxin Zhao, Yifan Wu, Chen Luo, Basit Zeshan, Zengqi Yang, Li Qiu, Yefei Zhou, Xinglong Wang
• Format: Article
• Language: English; English
• Published: Elsevier 2022
• Subjects: SF781-809 Communicable diseases of animals (General)
• Online Access: https://eprints.ums.edu.my/id/eprint/34800/1/Abstract.pdf; https://eprints.ums.edu.my/id/eprint/34800/2/Fulltext.pdf; https://eprints.ums.edu.my/id/eprint/34800/; https://www.sciencedirect.com/science/article/pii/S0378113522000670; https://doi.org/10.1016/j.vetmic.2022.109397

Porcine reproductive and respiratory syndrome virus (PRRSV) causes huge economic loss to China's swine industry. Currently, a novel type 2 PRRSV, called the NADC30-like strain, is epidemic in numerous provinces of China. In this study, a NADC30-Like PRRSV strain was isolated in primary alveolar macrophage (PAM) cells from fecal samples collected from a local pig farm, which suffered severe diarrhea. A pathogenicity comparison study was conducted in 6–week‐old piglets by inoculating highly pathogenic HP-PRRSV and NADC30-Like PRRSV isolates. RT-qPCR revealed detection of NADC30-Like PRRSV but not the HP-PRRSV in the intestine. PRRSV infection-related lesions were observed in the intestine were further confirmed by histopathological and immunohistochemically examination (IHC). In addition, severe virus infections were also detected by RT-qPCR. Based on clinical observation and pathogenicity experiments, we confirmed that NADC30-Like PRRSV gained more tissue tropism, especially in the small intestine. This may be the one reason explaining why NADC-Like 30 PRRSV become a major epidemic strain in China since the first outbreak in 2013.