Wang Yimin, Xia Shui-Li, Lei Jian-Lin, Cong Xin, Xiang Guang-Tao, Luo Yuzi, Sun Yuan, Qiu Hua-Ji
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China.
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China.
Vet Immunol Immunopathol. 2015 Dec 15;168(3-4):147-52. doi: 10.1016/j.vetimm.2015.10.011. Epub 2015 Nov 2.
Pseudorabies (PR) or Aujeszky's disease (AD), caused by pseudorabies virus (PRV), is an economically important viral disease in many countries. The modified live vaccine Bartha-K61 strain has played an important role in the control of PR in many countries including China. Since late 2011, however, increasing PR outbreaks caused by an emerging PRV variant have been reported in Bartha-K61-vaccinated swine population on many farms in China. Previously, we showed that the PRV variant TJ strain exhibited enhanced pathogenicity in pigs inoculated via intramuscular route. To develop an animal infection model for accurate evaluation of novel vaccines against the emergent PRV variant, we evaluated the pathogenicity of the PRV TJ strain of different doses in pigs infected via intranasal route. Groups (n=5) of 7-week-old healthy pigs were inoculated intranasally with 10(3), 10(4), 10(5), or 10(6) TCID50 (median tissue culture infective dose) PRV TJ strain. Clinical signs, rectal temperature, virus shedding, pathological changes, and seroconversion were monitored. The results showed that the PRV TJ strain induced varied morbidity and mortality (0/5 to 5/5), clinical signs, and tissue lesions, increasingly correlated with the infection doses, and the median lethal dose (LD50) of the virus was determined to be 10(4.5) TCID50. Together, this study demonstrates the dose-dependent pathogenicity of the PRV variant via the intranasal route of infection, which provides an ideal animal infection model for evaluation of novel vaccines against the emerging PRV variant.
伪狂犬病（PR）或奥耶斯基氏病（AD）由伪狂犬病病毒（PRV）引起，在许多国家都是一种具有重要经济影响的病毒性疾病。改良活疫苗Bartha-K61株在中国等许多国家的伪狂犬病防控中发挥了重要作用。然而，自2011年末以来，中国许多猪场接种过Bartha-K61疫苗的猪群中，由一种新出现的PRV变异株引起的伪狂犬病疫情不断增加。此前，我们发现PRV变异株TJ株经肌肉注射接种猪时表现出增强的致病性。为了建立一个动物感染模型以准确评估针对新出现的PRV变异株的新型疫苗，我们评估了经鼻内途径感染猪时不同剂量PRV TJ株的致病性。将7周龄健康猪分成若干组（每组n = 5），经鼻内接种10³、10⁴、10⁵或10⁶半数组织培养感染剂量（TCID50）的PRV TJ株。监测临床症状、直肠温度、病毒排泄、病理变化和血清转化情况。结果显示，PRV TJ株诱导了不同的发病率和死亡率（0/5至5/5）、临床症状和组织病变，且这些与感染剂量呈正相关，确定该病毒的半数致死剂量（LD50）为10⁴.⁵TCID50。总之，本研究证明了PRV变异株经鼻内感染途径具有剂量依赖性致病性，这为评估针对新出现的PRV变异株的新型疫苗提供了理想的动物感染模型。
