Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou Universitygrid.268415.c, Yangzhou, China.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou Universitygrid.268415.c, Yangzhou, China.
Microbiol Spectr. 2022 Aug 31;10(4):e0154122. doi: 10.1128/spectrum.01541-22. Epub 2022 Jun 29.
NADC34-like porcine reproductive and respiratory syndrome virus (PRRSV) has been reported to be prevalent in China since 2018 and became one of the main epidemic strains in some areas of China. Yet, the pathogenicity of NADC34-like PRRSV tested by experimental infection has seldomly been investigated. In this study, we infected pigs with JS2021NADC34 PRRSV, a Chinese NADC34-like PRRSV isolated in Jiangsu province in 2021, to study the pathogenicity of this virus strain. Pigs infected with this virus had lasting fever and reduced body weight with high morbidity and mortality. Histopathological changes, including interstitial pneumonia, lymphocyte depletion, acute hemorrhage, and infiltration of neutrophils in the lymphoid tissues, were observed with the viral proteins detected by immunohistochemistry staining using PRRSV-specific antibody. These results suggested that JS2021NADC34 PRRSV is highly pathogenic to pigs. As it is the latest emerging PRRSV strain in China, the prevalence and pathogenicity of NADC34-like PRRSV need to be further investigated. NADC34 PRRSV was initially reported in the United States in 2018. Subsequently, this virus strain spread to other countries, including Peru, South Korea, and China. The virus was first found circulating in Northeast China and then spread to more than 10 provinces in China. NADC34 PRRSV causes severe abortion of sows and high mortality of piglets, which lead to huge economic losses to the Chinese pig industry. However, the pathogenicity of NADC34 PRRSV was rarely experimentally evaluated on pigs. In this study, pigs were infected with JS2021NADC34 PRRSV, a Chinese NADC34-like PRRSV isolated in Jiangsu province in 2021. The infected pigs had lasting fever and reduced body weight with high morbidity and mortality. Interstitial pneumonia, lymphocyte depletion, acute hemorrhage, and infiltration of neutrophils were observed in the lymphoid tissues, and high virus load was proved by immunohistochemistry staining. The above results indicated that NADC34 PRRSV has high pathogenicity on pigs.
自 2018 年以来，中国已报告存在 NADC34 样猪繁殖与呼吸综合征病毒（PRRSV），并已成为中国部分地区的主要流行毒株之一。然而，通过实验感染测试的 NADC34 样 PRRSV 的致病性很少被研究。在这项研究中，我们用 2021 年江苏省分离的 NADC34 样 PRRSV 毒株 JS2021NADC34 感染猪，以研究该病毒株的致病性。感染这种病毒的猪持续发热，体重减轻，发病率和死亡率高。通过用 PRRSV 特异性抗体进行免疫组织化学染色，检测到病毒蛋白，观察到间质性肺炎、淋巴细胞耗竭、急性出血和淋巴组织中中性粒细胞浸润等组织病理学变化。这些结果表明，JS2021NADC34 PRRSV 对猪具有高度致病性。由于它是中国最新出现的 PRRSV 株，因此需要进一步研究 NADC34 样 PRRSV 的流行和致病性。
NADC34 PRRSV 最初于 2018 年在美国报告。随后，该病毒株传播到其他国家，包括秘鲁、韩国和中国。该病毒首先在中国东北地区流行，然后传播到中国 10 多个省份。NADC34 PRRSV 导致母猪严重流产和仔猪高死亡率，给中国养猪业造成巨大经济损失。然而，NADC34 PRRSV 的致病性很少在猪身上进行实验评估。在这项研究中，猪被感染了 JS2021NADC34 PRRSV，这是一种 2021 年在中国江苏省分离的 NADC34 样 PRRSV。感染猪出现持续发热和体重减轻，发病率和死亡率高。在淋巴组织中观察到间质性肺炎、淋巴细胞耗竭、急性出血和中性粒细胞浸润，并通过免疫组织化学染色证明了高病毒载量。上述结果表明，NADC34 PRRSV 对猪具有高致病性。
