高致病性猪繁殖与呼吸综合征病毒TJM-F92株减毒活疫苗临床免疫效果评价与分析

发布时间：2017-12-28 14:12

  本文关键词：高致病性猪繁殖与呼吸综合征病毒TJM-F92株减毒活疫苗临床免疫效果评价与分析　出处：《中国农业大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 猪繁殖与呼吸综合征 减毒活疫苗 安全性 免疫效果 临床评价

【摘要】：我国普遍采用减毒活疫苗免疫控制猪繁殖与呼吸综合征病毒(PRRSV)感染,但减毒活疫苗的临床安全性与效力受到关注。本研究以高致病性猪繁殖与呼吸综合征病毒TJM-F92株减毒活疫苗为对象,开展了其临床应用情况、安全性及免疫效果的评价与分析,以期为养猪实际生产中合理使用TJM-F92株减毒活疫苗提供科学依据。采用调查问卷的方式,2015年3月至5月对24个省的720个猪场进行了TJM-F92株减毒活疫苗应用情况的调查。结果显示,收到反馈信息的700个猪场中,母猪群使用TJM-F92株减毒活疫苗的安全性好、较好和一般的猪场分别占52.29%、40.57%和7.14%,93.13%的猪场采用对母猪群每年普免3-4次的方式；在生长猪群使用TJM-F92株减毒活疫苗的634个猪场中,免疫效果好、较好和不明显的猪场分别占29.96%、59.31%和10.73%。此外,分析发现生长猪的免疫效果与猪场位置、规模、生产方式以及采用的免疫程序有关。为进一步评价感染不同PRRSV毒株的猪场使用TJM-F92株减毒活疫苗的免疫效果,分析了我国猪群感染PRRSV毒株的状况和特点。2014年4月至2016年4月,对采集自15个省56个猪场的经RT-PCR检测PRRSV ORF7核酸为阳性的163份样本进行了ORF3、ORF5和NSP2高变区基因的扩增与序列测定和分析。结果显示,扩增的130个ORF3基因、139个ORF5基因和113个NSP2基因片段均属于PRRSV基因2型毒株,均可分为5个亚群,其中ORF3和ORF5基因各存在一个新亚群；在扩增的基因中,与高致病性PRRSV (HP-PRRSV)高度同源的ORF3、 ORF5、NSP2基因分别为68.46%、55.4%和84.07%;NSP2呈现11种缺失模式。通过对各个猪场、各个样本的3个目标基因的综合分析揭示了猪场临床感染PRRSV毒株的复杂性,研究共发现9类PRRSV野毒株,18类PRRSV毒株感染类型。HP-PRRSV、类NADC30、类VR-2332在猪群中出现的频率分别为66.07%、26.79%、8.93%。单独感染HP-PRRSV、类NADC30、类VR-2332等3类典型毒株的感染类型的猪场比例为53.57%,其中,单独感染HP-PRRSV毒株的猪场占比最高,为41.07%。感染疑似复杂毒株和2类或2类以上毒株混合感染类型的猪场比例为45.64%,其中,HP-PRRSV和类NADC30混合感染的毒株感染类型的猪场占比最高,为12.5%。为分析TJM-F92株减毒活疫苗在不同PRRSV毒株感染类型猪群的临床效果,对PRRSV毒株感染情况清楚的35个猪场,进行了TJM-F92株减毒活疫苗免疫后的临床效果调查。结果显示：免疫TJM-F92株减毒活疫苗后,临床改善显著、有改善、无改善的猪场比例分别为13/35、13/35、9/35。进一步的分析揭示了TJM-F92株减毒活疫苗在不同PRRSV毒株感染类型猪场的效果差异。单独感染HP-PRRSV毒株的猪场,免疫后改善显著、有改善和无改善的比例分别为50%、38.5%和12.5%,而类NADC30毒株感染猪场,疫苗免疫后未见显著改善。为进一步分析猪群持续TJM-F92株减毒活疫苗免疫后的临床安全性和效果,2014年7月至2016年1月追踪了一个PRRSV感染猪场使用疫苗前后的母猪产仔性能、分娩率和保育猪临床症状、各阶段成活率的情况,并定期采用ELISA和基因扩增与序列测定分别对免疫后的生长猪群PRRSV抗体变化和保育猪群的PRRSV毒株感染的情况进行了监测。结果显示,母猪群免疫TJM-F92株减毒活疫苗前后,其产仔性能、分娩率、断奶猪成活率差异都不显著。母猪在不同妊娠阶段接种TJM-F92株疫苗,对其产仔性能有不同的影响,在妊娠0-30大期间接种,相比其它妊娠阶段接种,母猪窝均木乃伊数最高,且差异显著,提示TJM-F92株减毒活疫苗在此妊娠阶段免疫存在不安全性。生长猪群免疫后,其临床症状显著改善,保育期与育肥期成活率分别为96.97±1.48%、97.50±0.61%,与疫苗免疫前的差异极显著。此外,发现保育猪的成活率与PRRSV感染时间以及毒株有关。由此表明,长期免疫TJM-F92株减毒活疫苗,有助于降低HP-PRRSV野毒株在猪群中的循环。综上所述,我们的研究较为系统地评价了TJM-F92株减毒活疫苗的临床安全性和免疫效果,对养猪生产中该疫苗的合理应用有指导价值。
[Abstract]:The attenuated live vaccine is widely used to control the infection of porcine reproductive and respiratory syndrome virus (PRRSV) in China. However, the clinical safety and efficacy of attenuated live vaccine is concerned. In this study, highly pathogenic porcine reproductive and respiratory syndrome virus TJM-F92 strain live attenuated vaccine for the object, to carry out the analysis and evaluation of its clinical application, safety and immune effect, in order to raise the actual production and rational use of TJM-F92 strain live attenuated vaccine to provide the scientific basis for. Questionnaires were used to investigate the application of TJM-F92 live attenuated vaccine to 720 pig farms in 24 provinces from March 2015 to May. The results showed that 700 pig farms receive feedback information, sow group TJM-F92 strain live attenuated vaccine safety is good, good and the general farms accounted for 52.29%, 40.57% and 7.14%, 93.13% pig farms use of sows group every year tax-free 3-4 times; in the growth of pigs using live attenuated vaccine strain TJM-F92 the 634 pig farms, the immune effect is good, good and not obvious farms accounted for 29.96%, 59.31% and 10.73%. In addition, it is found that the immune effect of growing pigs is related to the location, size, mode of production and the immune procedures used. In order to further evaluate the immunization effect of live attenuated strain TJM-F92 of swine infected with different PRRSV strains, the status and characteristics of swine infected PRRSV strains in China were analyzed. From April 2014 to April 2016, we amplified and sequenced and analyzed the ORF3, ORF5 and NSP2 hypervariable regions in 163 samples collected from 56 pig farms in 15 provinces and tested positive for PRRSV ORF7 nucleic acid by RT-PCR. The results showed that 130 ORF3 genes, 139 ORF5 genes and 113 NSP2 genes amplified fragments belong to the PRRSV genotype 2 strains can be divided into 5 subgroups, including ORF3 and ORF5 gene are a subset of; in the amplified gene, and highly pathogenic PRRSV (HP-PRRSV) high degree ORF3, ORF5, NSP2 homologous genes were 68.46%, 55.4% and 84.07%; NSP2 showed 11 missing pattern. Through the comprehensive analysis of 3 target genes in pig farms and samples, the complexity of PRRSV infection in swine farms was revealed. 9 types of PRRSV wild strains and 18 kinds of PRRSV strains were found. The frequencies of HP-PRRSV, NADC30 and VR-2332 in the pigs were 66.07%, 26.79% and 8.93% respectively. The infection rate of 3 typical strains infected with HP-PRRSV, NADC30 and VR-2332 was 53.57%, and the proportion of pigs infected with HP-PRRSV strain was 41.07%. The proportion of mixed farms infected with suspected complex strains and 2 or more than 2 kinds of strains was 45.64%, of which HP-PRRSV and NADC30 mixed infection strains accounted for the highest proportion of infected pig farms, 12.5%. In order to analyze the clinical effect of attenuated live vaccine of TJM-F92 strain in different PRRSV infected pigs, the clinical effect of live attenuated TJM-F92 strain vaccine was investigated in 35 pig farms with clear infection of PRRSV. The results showed that after immunized TJM-F92 strain live attenuated vaccine, the proportion of clinical improvement, improvement and no improvement were 13/35, 13/35 and 9/35, respectively. Further analysis revealed the difference in the effect of TJM-F92 strain live attenuated vaccine in different type of swine farms with different PRRSV strains. The proportion of pigs that were infected with HP-PRRSV virus alone significantly improved, improved and no improvement was 50%, 38.5% and 12.5%, respectively, while NADC30 like strains were not significantly improved after vaccination. For further analysis of swine TJM-F92 strain for live attenuated vaccine immunity after the clinical safety and efficacy, from July 2014 to January 2016 followed a PRRSV infection using pig vaccine before and after the survival rate of sows farrowing performance, delivery rate and conservation in various stages of clinical symptoms in pigs, the situation, and regularly by ELISA and gene amplification was monitored with the sequencing respectively. After immunization the growth of pig PRRSV antibody changes and conservation herd strains of PRRSV infection. The results showed that the baby performance, delivery rate and the survival rate of weanling pigs were not significant before and after the sow group immunized with TJM-F92 attenuated live vaccine. In the different stage of gestation sows inoculated with TJM-F92 vaccine, have different effects on the reproductive performance, vaccination during pregnancy 0-30, compared to the other stage of pregnancy sows were vaccinated, the highest number of mummy nest, and the difference was significant, suggesting that TJM-F92 attenuated live vaccine on the immune stage of pregnancy have security. After growing pigs, their clinical symptoms were significantly improved. The survival rate was 96.97 + 1.48% and 97.50 97.50, respectively. In addition, the survival rate of the protected pigs was related to the time of PRRSV infection and the strain. Therefore, the long-term immune TJM-F92 strain attenuated live vaccine can help to reduce the circulation of HP-PRRSV wild strains in the pigs. To sum up, our research systematically evaluated the clinical safety and immune effects of live attenuated vaccine of TJM-F92 strain, which is of guiding value to the rational application of the vaccine in pig production.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S858.28
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本文编号：1346312