State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No, 1 Xujiaping, Yanchangbao, Lanzhou, Gansu 730046, PR China.
Virol J. 2011 Feb 19;8:73. doi: 10.1186/1743-422X-8-73.
Porcine reproductive and respiratory syndrome virus (PRRSV) exhibits extensive genetic variation. The outbreak of a highly pathogenic PRRS in 2006 led us to investigate the extent of PRRSV genetic diversity in China. To this end, we analyzed the Nsp2 and ORF7 gene sequences of 98 Chinese PRRSV isolates.
Preliminary analysis indicated that highly pathogenic PRRSV strains with a 30-amino acid deletion in the Nsp2 protein are the dominant viruses circulating in China. Further analysis based on ORF7 sequences revealed that all Chinese isolates were divided into 5 subgroups, and that the highly pathogenic PRRSVs were distantly related to the MLV or CH-1R vaccine, raising doubts about the efficacy of these vaccines. The ORF7 sequence data also showed no apparent associations between geographic or temporal origin and heterogeneity of PRRSV in China.
These findings enhance our knowledge of the genetic characteristics of Chinese PRRSV isolates, and may facilitate the development of effective strategies for monitoring and controlling PRRSV in China.
猪繁殖与呼吸综合征病毒（PRRSV）表现出广泛的遗传变异。2006 年高致病性 PRRS 的爆发促使我们调查中国 PRRSV 遗传多样性的程度。为此，我们分析了 98 株中国 PRRSV 分离株的 Nsp2 和 ORF7 基因序列。
初步分析表明，Nsp2 蛋白中 30 个氨基酸缺失的高致病性 PRRSV 株是中国流行的主要病毒。基于 ORF7 序列的进一步分析表明，所有中国分离株分为 5 个亚群，高致病性 PRRSV 与 MLV 或 CH-1R 疫苗的亲缘关系较远，这对这些疫苗的效力提出了质疑。ORF7 序列数据还表明，中国 PRRSV 的地理或时间起源与异质性之间没有明显的关联。
这些发现增强了我们对中国 PRRSV 分离株遗传特征的认识，并可能有助于制定在中国监测和控制 PRRSV 的有效策略。
