2株与疫苗病毒高度同源的猪繁殖与呼吸综合征病毒的鉴定和致病性分析  

Isolation,Identification and Pathogenicity of Two Porcine Reproductive and Respiratory Syndrome Virus Isolates Highly Homologous to a Vaccine Strain

作　　者：崔丹丹[1] 王忠田[2] 常洪涛[1] 王新港[1] 王傲杰 周峰[1] 彭志锋[1] 李永涛[1] 陈陆[1] 赵军[1] 王川庆[1] 

机构地区：[1]河南农业大学牧医工程学院,郑州450002 [2]中国兽医药品监察所,北京100081

出　　处：《病毒学报》2017年第5期728-737,共10页Chinese Journal of Virology

基　　金：国家重点研发计划(项目号:2016YFD0501102);题目:潜在入侵的畜禽疫病检测鉴定新技术研究;河南省高校科技创新团队与支持计划资助项目(项目号:14IRTSHN015);题目:动物疫病防控新技术~~

摘　　要：为了解河南地区猪繁殖与呼吸综合征病毒(PRRSV)流行毒株的特征及致病性,对从河南省两个免疫过高致病性PRRSV(HP-PRRSV)减毒活疫苗后不久发病猪场分离的两株PRRSV HENZK-1和HENPDS-2进行了全基因组测序、分析和致病性研究。结果表明,两株PRRSV分离株与HP-PRRSV的细胞传代致弱疫苗株JXA1-P80/JXA1-R高度同源。致病性试验表明,感染HENZK-1和HENPDS-2的仔猪出现明显临床症状,包括高热、食欲减退、呼吸困难等,且肺部出现了肉眼和组织学病变;而同源商品疫苗对照组JXA1-R虽未出现明显临床症状,但日增重降低,肺部有肉眼和组织学病变,并检测、回收到病毒。综上所述,有理由认为HENZK-1和HENPDS-2是由HP-PRRSV疫苗株JXA1-R演化而来,其来源猪群临床发病与其毒力返强、疫苗毒株在解剖和组织学上的损伤和排毒能力有一定关系,但具体原因仍需进一步研究。本研究为谨慎使用高致病性PRRSV减毒活疫苗及PRRS控制策略提供了重要依据。Two porcine reproductive and respiratory syndrome virus （PRRSV） isolates, HENZK-1 and HENPDS-2, were isolated from twoPRRSV-vaccinated pig herds, respectively in Henan Province, China. Whole genome sequencing revealed that the two isolates were highly homologous to JXA1-PSO, an attenuated vaccine strain developed by serial passages of highly pathogenic PRRSV （HP-PRRSV） in Marc-145 cells. Pathogenicity test showed that pigs infected with HENZK-1 and HENPDS-2 exhibited the obvious clinical signs of the disease： high fever, anorexia and respiratory distress. Pathological examination showedthe severely gross and histopathological lesions in the lungs. The piglets inoculated with the live vaccine strain JXA1-R gave rise to decreased average daily weight gain （ADWG） as well as gross and histopathological lesions in the lungs similar to those caused by isolates HENZK-1 and HENPDS-2, although no other obvious clinical sighs else were observed in the piglets. Collectively, these results indicated that： （i） HENZK-1 and HENPDS-2 evolved from HP-PRRSV vaccine strain JXA1-R ; （ii） the major cause of the occurrence of clinic PRRS in the two herds, where the two isolates were originated,was related to regaining of the virulence for the two isolates and （iii） the histopathological virulence and viruses shedding ability of the vaccine strain JXA1-R are responsible for some clinic PRRS cases of commercial herds in the field. But the detailed mechanism needs further study. This study provides an important reference for the development, selection and caution usage of the live PRRS vaccines in the fields.

关 键 词：猪繁殖与呼吸综合征病毒(PRRSV) 分离鉴定 全基因组 序列分析 类JXA1-R疫苗株 致病性 

分 类 号：S852.65[农业科学—基础兽医学]