【作者】 刘涛；

【导师】 夏平安； 魏爱枝；

【作者基本信息】 河南农业大学 ， 预防兽医， 2007， 硕士

【摘要】 猪繁殖与呼吸综合征是能够引起母猪的繁殖障碍和新生仔猪呼吸症状的一种严重危害养猪业的传染病。20世纪90年代以来,此病已几乎传播到世界各养猪国家,造成世界养猪业严重经济损失。此病在中国的流行和分布也日益广泛,危害也日益严重。本试验目的通过血清学调查和毒株的分离鉴定,为河南省豫南地区的猪繁殖与呼吸综合征的防治工作提供参考依据。本试验对河南省豫南地区猪场进行PRRS抗体检测,免疫猪场检测血清653份,阳性率为66.3%。未免疫猪场检测血清1059份,阳性率为70.7%。调查结果表明:豫南地区的未免疫猪场存在PRRS野毒感染,豫南地区PRRSV感染分布不均,未免疫猪场阳性率比较高,不同年龄段的猪群感染程度不一。本试验从河南省豫南地区分离到2株猪繁殖与呼吸综合征病毒(PRRSV),分别命名为PRRSV HNXY-1/07、PRRSV HNXY-2/07。利用RT-PCR方法克隆了2个分离株的ORF5基因,并对ORF5基因和其推导氨基酸序列与不同来源的PRRSV毒株进行比较,结果表明,2个PRRSV分离株之间的ORF5基因及其推导的氨基酸同源性均大于94%;它们与北美洲型之间同源性为85%-98%,而与流行的欧洲型之间的同源性仅为57%-62.9%。对分离株ORF5基因的推导氨基酸序列进行变异分析,证实2个分离株均发生了变异,这表明河南省信阳地区流行的PRRSV为北美洲型变异株。更多还原

【Abstract】 Porcine reproductive and respiratory syndrome(PRRS)is a viral disease primarily causing respiratory problems in piglets and growers,but also causing respiratory failure in susceptible sows.Since 1990,PRRS has nearly transmitted to many parts of the world.Currently it is the most economically important infectious disease faced by swine industry of many countries.433 out of 653 sera abstracted from PRRS vaccine farms in South Henan and the positive rate was 66.3%.749 out of 1059 sera abstracted from PRRS not immune farms in South Henan and the positive rate was 70.7%.The survey results showed that not immune farms in the wild exist PRRS infection drug and Yunan throughout the uneven distribution of PRRSV infection and the number of farms over small areas relatively high positive rate and different age groups varying degrees of swine infection.Two PRRSV isolates named by HNXY-1/07 and HNXY-2/07 which were obtained from South Henan differet pig farms.A RT-PCR method was used to amplify the complete ORF5 gene of these virus.Identity and variation analysis of ORF5 gene and the deduced amino acid of these isolates with the other nine published Identity and variation analysis of ORF5 gene and the deduced amino acid of these isolates with the other nine published PRRSV.Isolates from different source showed that percent identity of the ORF5 gene and amino acid of these South Henan isolates share more than 94%identity to each other.Between these South Henan isolates and the other America isolates,the identity ranged from 85%to 98%respectively,but the South Henan isolates and LV have just 57%to 62.9%identity.Further comparision of the deduced amino acid sequence of ORF5 gene of Henan isolates with other America isolates indicated that some sites of GP5 have taken into mutation.So our results showed that the PRRSV isolates from herds experiencing acute PRRS outbreak in South Henan are mutant isolates of America genotype.更多还原