猪源马链球菌兽疫亚种灭活疫苗对小鼠的免疫效力评价

 【目的】评价中国不同地区猪源马链球菌兽疫亚种分离株抗原性的差异,为猪链球菌病疫苗的研制提供指导。【方法】取从国内10省市分离的10株猪源马链球菌兽疫亚种分离株,分别制备灭活疫苗,免疫12周龄ICR小鼠,用同源菌株和ATCC35246株攻击。【结果】以同源菌株攻击免疫小鼠,除CG-74-63株外,其余菌株的保护率均在90％以上;而以异源菌株ATCC35246进行攻击,免疫小鼠的免疫保护率为80%～100%。【结论】中国不同地区的猪源马链球菌兽疫亚种分离株的抗原性差异不大,单一菌株制备的疫苗具有保护性。     

周口地区犬瘟热流行病学调查

为掌握周口地区犬瘟热流行病学情况,采用临床症状观察与实验室诊断相结合的方法对周口市4县1区的6家动物医院共1 568份病例进行检测,并对犬瘟热的风险因素进行了评估。结果表明:检出犬瘟热阳性病例378份,总感染率为24.1%(378/1 568)。同时发现犬瘟热感染存在年龄、季节和免疫状况的差异。其中,3~12月龄的幼犬感染率较高;4月份和10月份是犬瘟热的高发期,感染率分别为14.0%和13.0%;未免疫接种的犬感染率和死亡率均较高。     

DNA疫苗研究进展

DNA疫苗的研究已成为疫苗研究领域的热点,被称为疫苗的第3次革命.分析了DNA疫苗的优缺点、免疫机制、优化策略等.     

Immunization of grouper, Epinephelus coioides, confers protection against a protozoan parasite, Cryptocaryon irritans

The present study aimed to determine whether protection is conferred by immunization of grouper, Epinephelus coioides, against a protozoan parasite, Cryptocaryon irritans. The immunization of E. coioides was carried out by a low level exposure of fish to live C. irritans theronts from predetermined number of tomonts and by an intraperitoneal injection of a vaccine consisting of formalin-killed C. irritans theronts.

Mucus titers detected by ELISA were significantly higher in fingerling and adult grouper subjected to the low level of exposure to C. irritans theronts at 3-week post-exposure compared to fish that had no previous exposure. In addition, significantly smaller tomonts were produced from adult grouper after three successive exposures than the tomonts produced after a single exposure to the parasite.

In the vaccine-immunization experiment, no mortality was monitored in fish that received high dose vaccine (100 μg/fish), while 40% cumulative mortality and 100% cumulative mortality were recorded in low dose group (10 μg/fish) and control group (PBS-injected), respectively. In the succeeding replicate, the vaccine-immunized group (high dose) had 37.5% cumulative mortality and 100% cumulative mortality for the control. In addition, a total of 1830 tomonts were collected at 5-day post-challenge from the control group while none from the vaccine-immunized group. Significantly fewer trophonts and tomonts were enumerated at 5-day and 7-day post-challenge, respectively, in the vaccine-immunized group than the control.

Results suggest that a protective immunity has been conferred on the immunized grouper as indicated by high antibody titers in the mucus of C. irritans-exposed fish and higher survival and fewer parasites in vaccine-immunized fish than the control groups. The conferred immunity played a major role in preventing or limiting the adhesion, invasion, and development of C. irritans theronts on the skin of the immunized grouper.     

Adjuvants in veterinary vaccines: modes of action and adverse effects

Vaccine adjuvants are chemicals, microbial components, or mammalian proteins that enhance the immune response to vaccine antigens. Interest in reducing vaccine-related adverse effects and inducing specific types of immunity has led to the development of numerous new adjuvants. Adjuvants in development or in experimental and commercial vaccines include aluminum salts (alum), oil emulsions, saponins, immune-stimulating complexes (ISCOMs), liposomes, microparticles, nonionic block copolymers, derivatized polysaccharides, cytokines, and a wide variety of bacterial derivatives. The mechanisms of action of these diverse compounds vary, as does their induction of cell-mediated and antibody responses. Factors influencing the selection of an adjuvant include animal species, specific pathogen, vaccine antigen, route of immunization, and type of immunity needed.     

PRRS ELISA试剂盒检测猪繁殖与呼吸综合征病毒抗体的应用

利用重组杆状病毒表达的PRRSV核衣壳蛋白作抗原制成ELISA诊断试剂盒，检测人工感染PRRSV猪血清、疫苗免疫抗体和田间血清，并与IDEXX公司生产的试剂盒进行比较。结果表明，该试剂盒在PRRSV感染后8天内就可检出感染性抗体，而用IDEXX公司生产的试剂盒在感染后的18天才检测到感染性抗体，对弱毒疫苗的免疫检测也基本能反映出疫苗的免疫应答状况。对华东地区PRRSV流行病学调查结果表明，PRRSV在国内普遍存在，同时也证明研制的试剂盒，是客观科学调查我国PRRS流行情较理想的检测工具。     

黄芪多糖提高鸡抗氧化作用对免疫功能的影响

本实验观察了黄芪多糖 (APS)对正常雏鸡血清中GSH -Px、SOD活性及MDA含量的影响。在不同日龄 (5d、 14d、 2 5d)、不同APS剂量 (0、 2 5、 5、 10mg/只 )水平下 ,以点眼滴鼻、皮下注射、肌肉注射的不同给药方式使用APS后 ,各试验组血清GSH -Px、SOD活性均表现显著升高 (p <0 0 5 ) ,MDA含量均表现显著降低 (p <0 0 5 )。表明APS可提高鸡的抗氧化作用 ,提示APS可通过增强免疫器官中GSH -Px、SOD活性提高免疫防御和免疫监视。     

抑制素免疫山羊卵巢对外源性促性腺激素的反应

用重组绵羊抑制素α亚单位在不发情季节主动免疫 4 0只波尔山羊。免疫前和免疫后用马的绒毛膜促性腺激素 (eCG)或猪的卵泡刺激素 (pFSH)处理。排卵通过超声波检测 ,胚胎用非手术法回收。试验结果表明 ,抑制素主动免疫能引起山羊超数排卵。     

生长抑素主动和被动免疫及基因免疫研究进展

生长抑素(somatostatin,SS)是下丘脑释放的14肽激素,在动物体内具有广泛的抑制作用,特别是对生长及免疫反应具有明显的影响,通过耗竭或免疫中和体内的SS水平相应提高生长激素(GH)等水平促进动物生长。文中简要介绍了生长抑素主动和被动免疫的研究进展及基因免疫的作用机理、特点及增强基因免疫的途径;阐述了生长抑素基因疫苗的研究和应用发展前景。     

内蒙古猪瘟流行病学调查及猪瘟病毒的分离

对内蒙古部分地区猪场进行了猪瘟流行病学调查，发现我区在较大范围内以非典型的猪瘟为主，发病多见于3月龄以下的仔猪，且以局部流行为主，母猪多呈隐性感染，部分母猪表现出繁殖障碍；个别地区仍有发病率和致死率较高的急性典型猪瘟，发病猪场不同程度上存在免疫程序不合理和免疫抑制性疾病。在此基础上对疑似病例进行了病理学检测和兔体交互免疫试验进行确诊，并对猪瘟野毒进行了分离。本研究不仅为内蒙古地区进一步作好猪瘟的防制提供了理论依据，而且为猪瘟野毒分子生物学的研究打下了基础。