Li Xiangdong, Wu Jiajun, Tan Feifei, Li Yingying, Ji Guobiao, Zhuang Jinshan, Zhai Xinyan, Tian Kegong
National Research Center for Veterinary Medicine, Cuiwei Road, High-Tech District, Luoyang, 471003 Henan Province People's Republic of China.
OIE Porcine Reproductive and Respiratory Syndrome Reference Laboratory, China Animal Disease Control Center, No. 20 Maizidian Road, Chaoyang District, Beijing, 100125 People's Republic of China.
Springerplus. 2016 Sep 29;5(1):1677. doi: 10.1186/s40064-016-3336-5. eCollection 2016.
The recent emergence of NADC30-like porcine reproductive and respiratory syndrome virus (PRRSV) in vaccinated pigs arose more attentions for the high incidents of mutation and recombination of PRRSVs.
In this study, we determined full-length genome sequences of two NADC30-like PRRSV isolates from recent PRRSV outbreaks in China. Phylogenetic analysis showed that these two isolates were clustered in an independent branch together with NADC30, an American isolate in 2008. Genetically, HNjz15 shared 95.6 % nucleotide similarity to NADC30 without any exotic gene insertion. By contrast, HNyc15 shared 93.8 % similarity to NADC30 with recombination with VR-2332 and CH-1a. Two more previously reported NADC30-like PRRSVs were also analyzed and had exotic gene insertions with different PRRSV strains in their nonstructural protein genes.
The above results showed the increased mutation and recombination rates of NADC30-like PRRSV under current vaccination pressure and a more pressing situation for the PRRSV eradication and control in China.
近期，在接种疫苗的猪群中出现的类NADC30型猪繁殖与呼吸综合征病毒（PRRSV）因PRRSV的高突变率和重组率而受到更多关注。
在本研究中，我们测定了来自中国近期PRRSV疫情的两株类NADC30型PRRSV分离株的全长基因组序列。系统发育分析表明，这两株分离株与2008年的美国分离株NADC30一起聚集在一个独立分支中。在基因方面，HNjz15与NADC30的核苷酸相似性为95.6%，没有任何外来基因插入。相比之下，HNyc15与NADC30的相似性为93.8%，与VR-2332和CH-1a发生了重组。我们还分析了另外两株先前报道的类NADC30型PRRSV，它们在非结构蛋白基因中与不同的PRRSV毒株有外来基因插入。
上述结果表明，在当前疫苗接种压力下，类NADC30型PRRSV的突变率和重组率增加，中国PRRSV的根除和控制形势更加紧迫。
