中国商品育肥猪场猪繁殖与呼吸综合征病毒的流行情况及遗传进化
Prevalence and genetic evolution of porcine reproductive and respiratory syndrome virus in commercial fattening pig farms in China.
作者信息
Li Chao, Zhao Jing, Li Wansheng, Xu Hu, Gong Bangjun, Sun Qi, Guo Zhenyang, Li Jinhao, Xiang Lirun, Tang Yan-Dong, Leng Chaoliang, Wang Qian, Peng Jinmei, Zhou Guohui, Liu Huairan, An Tongqing, Cai Xuehui, Tian Zhi-Jun, Zhang Hongliang
机构信息
State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, CAAS, No. 678 Haping Road, Xiangfang District, Harbin, 150001, China.
Henan Key Laboratory of Insect Biology in Funiu Mountain, Henan Provincial Engineering Laboratory of Insects Bioreactor, China-UK-NYNU-RRes Joint Laboratory of Insect Biology, Nanyang Normal University, Nanyang, 473061, China.
出版信息
Porcine Health Manag. 2024 Jan 22;10(1):5. doi: 10.1186/s40813-024-00356-y.
BACKGROUND
To investigate the prevalence and evolution of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) at commercial fattening pig farms, a total of 1397 clinical samples were collected from a single fattening cycle at seven pig farms in five provinces of China from 2020 to 2021.
RESULTS
The RT‒PCR results revealed that PRRSV was present on all seven farms, and the percentage of PRRSV-positive individuals was 17.54-53.33%. A total of 344 partial NSP2 gene sequences and 334 complete ORF5 gene sequences were obtained from the positive samples. The statistical results showed that PRRSV-2 was present on all seven commercial fattening farms, and PRRSV-1 was present on only one commercial fattening farm. A total of six PRRSV-2 subtypes were detected, and five of the seven farms had two or more PRRSV-2 subtypes. L1.8 (L1C) PRRSV was the dominant epidemic strain on five of the seven pig farms. Sequence analysis of L1.8 (L1C) PRRSV from different commercial fattening pig farms revealed that its consistency across farms varied substantially. The amino acid alignment results demonstrated that there were 131 aa discontinuous deletions in NSP2 between different L1.8 (L1C) PRRSV strains and that the GP5 mutation in L1.8 (L1C) PRRSV was mainly concentrated in the peptide signal region and T-cell epitopes. Selection pressure analysis of GP5 revealed that the use of the PRRSV MLV vaccine had no significant episodic diversifying effect on L1.8 (L1C) PRRSV.
CONCLUSION
PRRSV infection is common at commercial fattening pig farms in China, and the percentage of positive individuals is high. There are multiple PRRSV subtypes of infection at commercial fattening pig farms in China. L1.8 (L1C) is the main circulating PRRSV strain on commercial fattening pig farms. L1.8 (L1C) PRRSV detected at different commercial fattening pig farms exhibited substantial differences in consistency but similar molecular characteristics. The pressure on the GP5 of L1.8 (L1C) PRRSV may not be directly related to the use of the vaccines.
背景
为调查中国5个省份7个猪场商品育肥猪群中猪繁殖与呼吸综合征病毒（PRRSV）的流行情况及演变规律，于2020年至2021年从7个猪场的一个育肥周期中采集了1397份临床样本。
结果
RT-PCR结果显示，所有7个猪场均存在PRRSV，PRRSV阳性个体的比例为17.54%至53.33%。从阳性样本中总共获得了344个部分NSP2基因序列和334个完整的ORF5基因序列。统计结果表明，所有7个商品育肥猪场均存在PRRSV-2，仅1个商品育肥猪场存在PRRSV-1。共检测到6种PRRSV-2亚型，7个猪场中有5个猪场存在两种或更多种PRRSV-2亚型。L1.8（L1C）PRRSV是7个猪场中5个猪场的优势流行毒株。对来自不同商品育肥猪场的L1.8（L1C）PRRSV进行序列分析发现，不同猪场间其一致性差异很大。氨基酸比对结果表明，不同L1.8（L1C）PRRSV毒株的NSP2存在131个氨基酸的不连续缺失，且L1.8（L1C）PRRSV的GP5突变主要集中在肽信号区和T细胞表位。对GP5的选择压力分析表明，使用PRRSV MLV疫苗对L1.8（L1C）PRRSV没有显著的阶段性多样化影响。
结论
PRRSV感染在中国商品育肥猪场中普遍存在，阳性个体比例较高。中国商品育肥猪场存在多种PRRSV亚型感染。L1.8（L1C）是商品育肥猪场中主要流行的PRRSV毒株。在不同商品育肥猪场检测到的L1.8（L1C）PRRSV在一致性上存在显著差异，但分子特征相似。L1.8（L1C）PRRSV的GP5所受压力可能与疫苗使用没有直接关系。
Zotero 插件