中国兽医科学2011，Vol.41Issue(2)：152-158,7.
高致病性猪繁殖与呼吸综合征病毒HBR变异株第125代的毒力试验
Virulence test of a highly pathogenic HBR 125 mutant strain of porcine reproductive and respiratory syndrome virus
摘要
Abstract
A highly pathogenic mutant strain(HBR) of porcine reproductive and respiratory syndrome virus(PRRSV) was isolated from clinical cases. Through viral passage in cell culture and plaque purification,a replication-stable strain was obtained. To examine the changes in virulence during the process of cell culture passage,the 125th generation of PRRSV-HBR culture at a titer of 107.5 TCID50/mL was used to inoculate eighteen 35-day-old pigs with PRRSV antibody negative by means of intramuscular injection and intranasal inoculation. Mock infected group was set up simultaneously for comparison. After viral inoculation, infected pigs did not show clinical symptoms such as obvious increases in body temperature, loss of appetite,listlessness,weight loss, eyelid swelling,or swollen superficial lymph nodes. Viremia was tested by RT-PCR. Positives appeared on day 3 and peaked on days 7 to 14,returning to negative after 28 days. Pigs were sacrificed at regular intervals to examine viral antigens in different organs. The results indicated that most organs taken from the infected pigs showed positive reactions after 1 to 2 weeks. After 3 to 6 weeks,the virus was concentrated in tissues such as the spleen,inguinal lymph nodes, and submandibular lymph nodes. Pathological examination showed that the lymph nodes and lungs of the infected pigs contained mild lesions on week 1 to 2 post-infection. The infectivity assays indicated that although the 125th generation of PRRSV-HBR cultured virus did not exhibit visible clinical symptoms,it still clearly possessed virulence demonstrated by viremia testing, viral distribution within the body, and pathological changes. Further attenuation is needed for the development of live vaccine.关键词
猪繁殖与呼吸综合征病毒/变异毒株/细胞传代/毒力试验分类
农业科技引用本文复制引用
危艳武,刘长明,范培虎,吴洪丽,温士刚..高致病性猪繁殖与呼吸综合征病毒HBR变异株第125代的毒力试验[J].中国兽医科学,2011,41(2):152-158,7.基金项目
国家自然科学基金资助项目(30871859) （30871859）
中央级公益性科研院所基本科研业务费(2010-054) （2010-054）
