Evaluation of colostral immunity in swine with commercial anti-leptospira polyvalent whole-bacteria vaccine

The intensity and duration of passive immunity against swine leptospirosis were investigated by the microscopic agglutination test and in vitro leptospira growth inhibition. Twenty-one females at first parturition were divided into three groups: Group A (n=08): received two doses with 30 days interval of the commercial anti-leptospira bacterin A. Group B (n=06) received two doses with 30 days interval of the commercial anti-leptospira bacterin B and Group C (n=07) was the control. In all groups the colostrums were collected. Blood collection of piglets was performed in four different ages. Agglutinin antibodies were equally detected in sera and colostrums for serovars Canicola, Grippotyphosa, Copenhageni, Icterohaemorrhagiae and Pomona (Group A) and Canicola, Copenhageni, Icterohaemorrhagiae, Pomona and Hardjo (Group B). Mean neutralizing antibodies titers were low. Passive immunity was low duration.     

猪链球菌多价灭活疫苗安全性和免疫原性试验

猪的链球菌感染已成为世界性的猪传染病。在国外 ,多由 D群链球菌的某些血清型特别是 2型猪链球菌 (Streptococci suis)引起猪的败血型和脑炎型链球菌病 [2、3、6、7、8]。而在国内对猪链球菌致病菌的研究证实 ,以 C群的兽疫链球菌为主 ,D群较少[1、4、5] ,E群链球菌则引起慢性链球菌病的关节炎和淋巴结炎 (脓肿 ) [2 ] 。近几年来我们发现 ,有些猪场对各类猪群均进行过链球菌苗的接种 ,但仍然大批发生链球菌病 ,造成大量死亡 ,后来经过对分离的致病菌作分群鉴定 ,同时对发病猪群采血检测群特异性抗体 ,结果发现免疫的疫苗抗原的菌群与当…     

黄芪多糖对猪瘟弱毒疫苗的免疫增强作用

本研究旨在探讨黄芪多糖对猪瘟疫苗免疫的影响.把21日龄断奶仔猪分成4组,在2～4组仔猪基础日粮中分别添加浓度为2×10-4、3×10-4、4×10-4的黄芪多糖,连续饲喂7d;第1组日粮中不添加任何药物,作为空白对照组.用药结束后用猪瘟弱毒疫苗免疫,并于免疫后第1、3、5周分别用正向间接血凝抑制试验和流式细胞术检测外周血猪瘟抗体效价及淋巴细胞亚群动态.结果显示:与对照组相比,黄芪多糖能提高仔猪外周血猪瘟抗体水平1个滴度以上,具有提高CD3+、CD4+T淋巴细胞百分数的趋势.说明黄芪多糖能提高仔猪特异性免疫力,是良好的免疫增强荆.     

Vaccination of swine with an inactivated porcine parvovirus vaccine in the presence of passive immunity

A study was conducted to determine whether low hemagglutination inhibiting (HI) titers (1:5) for porcine parvovirus (PPV) block the development of immune response to a PPV vaccine. Pigs with low (1:5), medium (1:10 or 1:20), or high (1:40 or 1:80) titers were obtained by IV injections with various amounts of PPV immune serum. Pigs were inoculated with 1 or 2 doses of vaccine and were monitored for serum HI antibodies to PPV. Pigs with low titers responded to vaccine just as well as did the seronegative pigs. The HI titers of pigs with medium titers did not increase after first vaccination. After the second vaccination, however, their titers increased and were similar to those of pigs with low titers. High titers blocked the response to vaccination. The pigs that received 2 doses of vaccine had higher titers than did those of pigs that received 1 dose of vaccine. The results indicated that low titers, which would be expected in gilts at the time of vaccination, do not interfere with immunization by the inactivated PPV vaccine, and that 2 doses of vaccine may provide better and longer lasting immune response to inactivated PPV vaccine and probably longer lasting immunity against PPV-induced reproductive failure.     

Intestinal phospholipase B activity in swine inoculated with Trichinella spiralis

Trichinella spiralis was studied in outbred swine to determine whether infection would cause an increase in intestinal phospholipase B (EC 3.1.1.5) activity and in number of peripheral eosinophils. Intestinal phospholipase B activities increased and were accompanied by eosinophilia. The response was similar to that found in rodents infected with helminth parasites, thus demonstrating that phospholipase B is not unique to rodent models and is probably part of the complex immune response of the host in defense against parasitic infections.