首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 390 毫秒
1.
鸡球虫疫苗研究进展   总被引:43,自引:10,他引:33  
鸡球虫病是生产中严重危害养禽业的寄生虫病,长期以来以药物防治为主。目前,由于球虫耐药性的普遍存在,加上消费者对禽产品药物残留问题的关注,采用疫苗防治球虫病为人心所向。球虫活苗在实际生产中发挥了一定的作用,但由于球虫活苗存在“复壮”的可能且使用麻烦,人们将目光转向了分子疫苗。球虫基因组学研究为基因工程苗开发奠定了基础,目前已经筛选了上百个功能抗原基因。受表达系统的限制,原核表达的重组蛋白抗原性较差,虽有较多尝试,但鲜有成功。人们在探索体外真核表达(如酵母、杆状病毒表达系统等)的同时,核酸疫苗以其独特的诱发高水平细胞免疫反应的能力而倍受青睐,近几年发展较快。  相似文献   

2.
Field trials were conducted to establish the effect of the use of an inactivated oil emulsion vaccine against Infectious Bursal Disease (IBD OEV) in broiler breeder hens, and its effects on their progeny. The performance of 18 broiler flocks, which were the progeny of the IBD OEV vaccinated breeder hens, but which were not vaccinated with a live vaccine against IBD, was equal to that of broiler flocks which were vaccinated with a live IBD vaccine and originated from parent stock that had been vaccinated only against IBD with a live vaccine. In none of the 18 flocks, progeny of IBD OEV vaccinated parents, was IBD diagnosed. In a second stage, 15 broiler flocks were included in the trial: these were derived partly from IBD OEV vaccinated parents, and partly from parents that received only live IBD vaccine at 8-10 days of age. No cases of IBD occurred and all flocks were positive for IBD precipitins at slaughter age. Vaccination with a live vaccine against IBD at the age of 8-10 days had no influence on NCD antibody development after a NCD vaccination at 7 days. No immunosuppressive effect from this type of live live IBD vaccine could be determined under field conditions.  相似文献   

3.
布鲁氏菌病(布病)活疫苗是世界各国防控布病的重要生物资源,我国目前主要生产和应用的布病活疫苗为S2株和A19株。生物安全是布病活疫苗生产过程中的必须优先考虑的重要环节,随着兽药GMP(2020年版)的即将实施,规范布病活疫苗的生产与检验,防控生产环节中的生物安全风险,成为迫切需要研究和解决的突出问题。本文通过对布病活疫苗生产检验、设施维修维护、生产人员个人防护等环节的生物安全风险点进行分析,对布病活疫苗生产线提出改进建议,为相关企业动物布病活疫苗生产提供参考。  相似文献   

4.
To use the advantages of both the competitive exclusion (CE) technique and immunization with a live Salmonella vaccine, the combination of these methods was studied. Specific-pathogen-free chickens were pretreated by combined or single administration of a CE culture and a commercial live Salmonella typhimurium vaccine on days 1 and 2 of life and challenged with Salmonella typhimurium on day 3 to study the exclusion effect by both the CE preparation and the Salmonella vaccine. The exclusion effect by the CE culture combined with the immunologic effect by the live vaccine was studied after challenge of the birds on day 43 of age. The number of challenge organisms in ceca was used to evaluate the efficacy of the pretreatment. The protective exclusion effect of the CE culture was substantial in very young chicks and still detectable in 6-wk-old birds. The attenuated Salmonella typhimurium vaccine produced only an initially occurring exclusion effect. Because the exclusion effect of the CE culture was considerably stronger than the exclusion effect of the attenuated Salmonella typhimurium vaccine, the combination of both did not result in an additive protective effect. In order to exploit the exclusion potential between Salmonella strains and to attain an additive exclusion effect by a CE culture and a vaccine strain, live Salmonella vaccines are needed that are sufficiently attenuated without affecting genes essential for colonization exclusion of other Salmonella organisms. In 6-wk-old birds, the exclusion effect by the CE culture combined with the immunologic effect by the live Salmonella vaccine resulted in a degree of protection considerably beyond that generated by the exclusive use of the two methods. The administration of the live Salmonella vaccine strain prior to or simultaneously with the CE culture revealed the best protective effect because such combinations ensure an adequate persistence of the vaccine strain as prerequisite for the expression of an exclusion effect in very young chicks and the development of a strong immune response affording protection in older birds.  相似文献   

5.
A commercial live attenuated, freeze-dried avian metapneumovirus vaccine, Pneumomune, was assessed for its viability at three different temperatures (5.6 C, 21 C, and 37 C). No significant reduction in virus titer was observed when the vaccine was stored at 5.6 C for a period of 24 hr. However, reductions in virus titer of 1 log10 and 2 log10 were observed after 24 hr at 21 C and 37 C, respectively. Batch-to-batch variation in virus reduction was also observed. The addition of a dye or a vaccine stabilizer to the vaccine preparation did not have any deleterious effect on the survival of vaccine virus.  相似文献   

6.
为比较猪瘟疫苗E2基因工程亚单位疫苗和猪瘟活疫苗对育肥猪免疫效果和生产成绩的影响,以便为规模猪场在选择猪瘟疫苗时提供参考。本试验从汉中某代养场选取了一批健康的断奶仔猪分成三组,A组免疫猪瘟E2基因工程亚单位疫苗(简称E2亚单位疫苗),B组免疫猪瘟活疫苗(脾淋源),C组为对照组不做猪瘟疫苗免疫。免疫60 d后各组随机抽取10、15和12份血样用猪瘟病毒抗体检测试剂盒检测猪瘟抗体水平。结果表明接种的两种猪瘟疫苗对育肥猪的免疫效果差异极显著(P<0.01),其中E2亚单位疫苗相比于猪瘟活疫苗能够明显提高育肥猪抗体阻断率和降低离散度,并且有助于育肥猪的健康生长。  相似文献   

7.
Day-old broilers were administered live and/or inactivated vaccines to assess vaccine efficacy against challenge with Newcastle disease (ND) and infectious bursal disease (IBD). Chicks were from commercial breeder pullets vaccinated against ND and IBD using several live vaccine primers followed by an inactivated ND-IBD vaccine at 18 weeks. The most efficacious initial ND-IBD vaccination program was live ND virus by eye drop and live IBD vaccine injected subcutaneously (SQ) followed 2 hours later with inactivated ND-IBD vaccine SQ. The next two most efficacious programs were live vaccine alone and the inactivated vaccine only. Inactivated vaccine given SQ had no adverse effect on live IBD vaccine given 2 hours earlier in a similar site. Administration of inactivated vaccine by vent was not as efficacious as administration SQ. A booster of a second live ND-IBD vaccine drinking water at 18 days significantly increased levels of circulating antibody, regardless of the initial vaccination program.  相似文献   

8.
犬瘟热的诊断及其预防免疫的研究进展   总被引:36,自引:7,他引:29  
本文对犬瘟热(CD)的诊断、预防免疫和免疫失败的影响因素及犬瘟热病毒(CDV)的宿主范围进行了综述。CDV不仅感染陆生食肉动物,而且也感染水生食肉动物,并且其宿主范围还在不断扩大。CDV感染主要采用病毒分离、特异性病毒抗原或特异性核酸检测等方法确诊。疫苗包括灭活的CDV疫苗、麻疹病毒(MV)异源苗及CDV弱毒活苗。疫苗接种犬的免疫反应主要取决于毒株特性及犬的应答能力,只有弱毒活苗能诱导产生持久而坚强的保护力。尽管多年来CDV弱毒活苗的使用控制了CD的发生,但最近免疫过的犬发生CD的病例并不少见。分析免疫失败的原因,主要是母源抗体干扰、疫苗质量差、其它病毒的免疫抑制以及CDV流行株可能发生了变异等因素的影响。  相似文献   

9.
DNA疫苗是继减毒疫苗,灭活疫苗,亚单位疫苗和重组多肽疫苗之后的又一新型疫苗,比其它疫苗高效。安全且易于大量生产。本文对DNA疫苗在牛,猪和鸡一些病毒病上的使用效果及其安全问题等方面的研究近况作一综述。  相似文献   

10.
A protease activation mutant of Sendai virus, TR-5, was investigated as a candidate for a live vaccine. Vaccination with TR-5 which had been activated by chymotrypsin beforehand (active TR-5) elicited protective immunity against otherwise lethal challenge infection with wild-type Sendai virus in DBA/2, C3H and ICR strains of mice. Less of the active TR-5 was required to confer protection on mice compared with an ordinary ether-inactivated Sendai virus vaccine (split vaccine). The protective immunity elicited by TR-5 lasted longer and the booster effect was more prominent compared to the split vaccine. No seroconversion was observed with contact mice when housed in a cage with mice vaccinated with the active TR-5. The overall results show that the active TR-5 is an effective and safe live vaccine of Sendai virus in mice.  相似文献   

11.
A live attenuated vaccine virus variant of Rift Valley fever (RVF) virus was developed by passaging a human isolate in tissue culture under the influence of the mutagen 5-fluorouracil. This virus variant (MV P12) has been assessed in this study as to its suitability as a vaccine, by testing its pathogenicity in young lambs and measuring its ability to induce a protective immune response. Even high doses of the vaccine virus failed to induce any of the clinical or histopathologic changes associated with classical RVF virus infection. Although the vaccine induced mild pyrexia when given in high doses, viremia was not induced. Neutralizing antibody and a protective immune response was elicited with even low doses of vaccine virus. These data, along with data of other workers on the lack of abortigenicity of this virus variant, indicate that the MV P12 variant of RVF virus is an excellent candidate for a safe and effective vaccine against RVF.  相似文献   

12.
Previous findings, viz. that mice can be successfully immunized against infection with Salmonella dublin with either live or inactivated vaccine, were confirmed. Immunity lasted for at least 12 weeks in mice which had been immunized with inactivated alum-precipitated vaccine. The immunogenicity of inactivated vaccine gradually decreased on storage at 4 degrees C, but this was only detectable if a single injection was used for immunization: 2 injections virtually eliminated this phenomenon. The immunogenicity of live vaccine in mice was not enhanced by levamizole or the simultaneous injection of inactivated organisms. Both live and inactivated vaccines provided immunity in calves. A single injection of lyophilized vaccine, prepared from live rough Salmonella dublin strain (HB 1/17),protected 3 out of 6 calves, while 2 injections of a formalin-inactivated, alum-precipated vaccine, containing 1% packed cells of S. dublin strain 2652 V, protected 5 out of 6 calves against intraduodenal challenge with 2 x 10(9), S. dublin strain 2652 V. Two calves which had been immunized with an inactivated oil adjuvant vaccine were also solidly immune to this challenge. Serum antibody response in calves was poor when measured by the tube agglutination and the haemagglutination tests. Similarly, the sera had only marginal protective values when tested by means of a passive protection test in mice. Antibody titres alone are not a valid measure therefore, for the immune status of immunized animals.  相似文献   

13.
现有的布鲁菌减毒活疫苗存在一定毒力,且野强毒株和减毒活疫苗株间缺少可供鉴别的抗原,导致在血清学检测上自然感染与疫苗接种很难区分,限制了现有的减毒活疫苗的广泛应用.本文拟对布鲁菌的减毒活疫苗株S2进行遗传改造,克服上述缺陷.本研究利用同源重组的方法,得到了布鲁菌S2株omp10基因缺失株.分别用基因缺失株和疫苗株感染小鼠,比较基因缺失株小鼠体内的存活能力.结果成功构建了布鲁菌S2株omp10基因缺失株,动物试验结果表明,基因缺失株仍能在小鼠体内存活,具备作为减毒活疫苗的特性.与原始S2株比较,基因缺失株的感染力进一步减弱.表明omp10基因在布鲁菌的毒力及体内生存方面发挥了作用,为基因标记疫苗的研制奠定了基础.  相似文献   

14.
乳酸菌以其益生性、佐剂效应、制备简单及生产成本低等优点被广泛用于各种病原抗原的传递载体研究。乳酸菌活载体疫苗能同时激发机体的体液免疫、黏膜免疫和细胞免疫反应,是目前疫苗研究领域的一个热点。作者分别对乳酸菌活载体疫苗的作用机理、传递外源抗原的形式进行概括,对其在预防各种病毒性、细菌性和寄生虫性等疾病的研究进行综述,并对其存在的问题、应用前景进行分析和展望。  相似文献   

15.
三个厂家猪瘟活疫苗免疫效果比较试验   总被引:1,自引:0,他引:1  
在同一条件下对3个厂家生产的猪瘟细胞源活疫苗进行了免疫效果评价试验,并与猪瘟传代细胞苗免疫效果进行比较。结果发现3个厂家生产的猪瘟细胞源活疫苗存在一定差异,2个厂家的免疫效果较好,1个厂家的免疫效果较差。猪瘟传代细胞苗免疫效果优于猪瘟细胞源活疫苗,猪瘟传代细胞苗免疫1次,抗体合格率高,持续时间长,猪瘟细胞源活疫苗要免疫两次才能获得比较好的效果。同时,我们发现高致病性猪蓝耳病活疫苗(JXA1-R株)对猪瘟抗体产生有一定影响。  相似文献   

16.
本文对鸡法氏囊提取液与ND活疫苗的使用方法进行了分析。通过血凝抑制抗体滴度的测定结果表明,预先接种鸡法氏囊提取液时,经肌肉注射、口服和点眼滴鼻接种方式均能提高ND疫苗免疫鸡的抗体产生能力,且经肌肉注射法最佳。但是,在整个试验期间,法氏囊提取液只能增强鸡群对ND活疫苗的早期免疫应答,而法氏囊提取液与ND活疫苗同时使用时更能刺激免疫鸡群的早期抗体产生水平。  相似文献   

17.
本研究旨在探讨饮水中添加不同剂量氟苯尼考对肉鸡新城疫活疫苗免疫效果的影响,确定氟苯尼考的最适使用剂量,为临床应用氟苯尼考提供合理的科学依据。试验将150只14日龄肉鸡分成5组(对照组及试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组)。对照组正常饮水,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在饮水中添加水溶性氟苯尼考50、100、200、400 mg/L,通过测定血清中鸡新城疫病毒抗体效价及IL-10、INF-γ含量,比较分析添加不同剂量的氟苯尼考对新城疫活疫苗免疫效果的影响。结果显示,试验Ⅰ和Ⅱ组血清中鸡新城疫病毒抗体效价及IL-10、INF-γ含量与对照组相比差异均不显著(P>0.05),但试验Ⅲ和Ⅳ组与对照组相比均差异显著(P<0.05)。结果表明,饮水中添加低剂量氟苯尼考(50、100 mg/L)对鸡新城疫活疫苗免疫效果不产生影响,但添加高剂量氟苯尼考(200、400 mg/L)对鸡新城疫活疫苗免疫效果产生免疫抑制作用。  相似文献   

18.
非洲猪瘟(African swine fever,ASF)给全球养殖业造成了巨大的威胁和挑战.非洲猪瘟病毒(African swine fever virus,ASFV)具有比寻常病毒更加巨大的基因组、迅速的变异能力和更加复杂多变的免疫逃逸机制,目前市场上仍无有效预防疫苗.科研人员几十年来,从灭活疫苗、减毒活疫苗、亚单...  相似文献   

19.
Mycoplasma gallisepticum causes respiratory disease and production losses in poultry. Vaccination of poultry with M. gallisepticum live vaccines is an approach to reduce susceptibility to infection and to prevent the economic losses. The development and evaluation of live vaccines usually requires the involvement of several vaccine and challenge strains in the same experimental setup. Our goal was to develop a tool to allow the differentiation between a set of known M. gallisepticum strains in a quantitative manner. We developed 5 real-time PCR assays that absolutely differentiated between one of the five commercial and laboratory vaccine strains: F, ts-11, 6/85, K5831, K5054, and the challenge strain R low when tested on in vitro cultures. The assay K5831 vs. R low was also tested on specimens from live birds that were vaccinated with K5831 and challenged with R low, and successfully differentiated between the vaccine and the challenge strains in a quantitative manner. This preliminary in vivo application of the method also shed light on possible protection mechanisms for the M. gallisepticum K5831 vaccine strain.  相似文献   

20.
鸡球虫疫苗研究现状   总被引:2,自引:0,他引:2  
鸡球虫病是危害养禽业的一类重要的寄生虫病,鸡球虫疫苗包括活疫苗、亚单位疫苗、基因工程亚单位疫苗、核酸疫苗及活载体疫苗等,论文对目前鸡球虫疫苗的研究与应用现状进行了综述.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号