Electrophoretic Studies of Sera from Cattle Vaccinated or Naturally Infected with Brucella Abortus

Examinations of the electrophoretic behaviour in cellulose acetate were made on the proteins of sera from 18 field cases of brucellosis, 15 calves recently vaccinated with strain 19 Brucella abortus and from 28 normal cattle. The total protein and γ-globulin content of the sera of the naturally infected, serologically positive cattle tended to be somewhat higher than that of sera from most normal cattle. A few of the serologically-negative normals also had defenitely elevated serum γ-globulin values. In the vaccinated calves there was an increase both in total serum protein and γ-globulin but its magnitude in different individuals was not directly related to the rise in their antibody titre.     

Chromatographic Studies of Sera from Calves Vaccinated with Brucella Abortus, Strain 19

The presence of antibody was detected by agglutination tests in the serum of calves four days after vaccination with Brucella abortus strain 19. Titres had reached a maximum by seven to ten days post-vaccination. Sucrose density-gradient ultracentrifugation demonstrated that the earliest antibodies were macroglobulins, IgM (19Sγ; γM)-globulins. Lighter antibodies, IgG (7Sγ₂; γG)-globulins, appeared a few days later. With time, antibody titres fell, IgM declining somewhat more quickly than IgG. After revaccination some seven months later, there was a rapid rise in both IgM and IgG.

Anion-exchange column chromatography (DEAE-cellulose) and gel filtration (Sephadex G-200) were applied in separating the two forms of antibody. The former method, in which a gradient buffer system was used, proved to be the more efficient; the IgG antibodies apeared in early eluates at pH 7.8 to 8.0 and low ionic strength, 0.03M, whereas IgM was eluted late when the pH had fallen below 6.0 and the molarity had increased to beyond 0.2. DEAE cellulose chromatography detected IgG as well as IgM sera collected as early as five days after vaccination.

     

A Preliminary Study of the Development of 19s and 7s Immunoglobulins in Sera of Two Sheep Vaccinated With Brucella Abortus, Strain 19

The pattern of antibody response to vaccination with Brucella abortus, strain 19, was studied in two sheep. Agglutinative activity was detected by the third and fifth days and complement - fixing activity by the fifth and seventh days post-vaccination.

Density gradient centrifugation and DEAE cellulose column chromatography showed the 19S antibody developed first, followed soon after by 7S antibody. The former had disappeared by the 25th day but the latter persisted longer in both sheep. A small amount of 19S antibody was detected in sheep 1 following a booster dose of vaccine but 7S antibody constituted the major secondary response.

The standard tube agglutination test was found to be more efficient than the complement-fixation test for titration of 19S antibody. An increase in the salt concentration to 10% in tube agglutination test rendered it more sensitive in demonstrating 7S antibody.

     

Antibody Development in Pigs Inoculated with Live or Killed Cultures of Brucella Abortus

As shown by density gradient ultracentrifugation and column chromatography, pigs formed IgM antibodies during the first week following vaccination with Brucella abortus, strain 19. At this time their sera reacted in both plate and tube agglutination but not in complement-fixation tests. A few days later, when IgG antibodies had developed, agglutination titers were still high and some activity was recorded in hemolytic complement-fixation tests. A similar sequence was observed in pigs repeatedly inoculated with phenol-killed suspensions of B. abortus. As the proportion of IgM to IgG antibodies decreased, agglutinin titers fell in relation to complement-fixing titers. In some animals the conglutinating complement absorption test became positive earlier than the plate agglutination.     

鉴别布鲁菌病自然感染动物与疫苗免疫动物胶体金检测试纸条的研制

用金黄色葡萄球菌A蛋白（SPA）标记胶体金技术制作金标垫,以亲和层析法纯化的BP26蛋白作为检测抗原（T线）,研制胶体金快速检测试纸条。用建立的试纸条检测小鼠布鲁菌感染血清,可成功鉴别牛布鲁菌S19感染和BP26缺失疫苗株YZ-2免疫的小鼠。试纸条检测与布鲁菌属同源性较近的几株细菌的阳性血清,结果无交叉反应;试纸条敏感性高于虎红平板凝集试验检测方法,近似于ELISA方法;准确性同于ELISA法,且更为简便快捷。该试纸条具有鉴别布鲁菌病自然感染和疫苗免疫的应用前景。     

Demonstration of Complement Fixing Antibody in the Sera of Cattle Vaccinated with Combined Living Blackleg-anthrax Vaccine

Complement fixing antibodies could be detected in the sera of cattle vaccinated with combined living blackleg-anthrax vaccine by modified complement fixation tests. Conventional direct complement fixation tests with bovine antibody-antigen systems often caused false negative reactions; however, in the modified test, when guinea pig complement was supplemented with fresh unheated normal rabbit serum, positive reactions were obtained and the sensitivity of the test was increased without loss of specificity.     

自然感染附红细胞体牛血液免疫指标的变化

附红细胞体病是由附红细胞体引起的一种人兽共患传染病,虽早在1928年就被发现,但由于多呈隐性感染,所以易被人们忽视,直至上世纪80年代,由于对畜牧业造成巨大危害,甚至危及人身健康,才逐渐被重视起来。到目前为止,国内大部分研究仅局限于该病的流行病学调查、诊断和治疗,但有关致病机理方面的研究还不多。附红细胞体的种类很多,现已正式命名的有14种,温氏附红体(E.wenyoni)是引起牛附红体病的病原体。本试验研究了不同感染程度牛红细胞免疫功能及血液中ANAE T淋巴细胞百分率的变化,旨在为探讨附红细胞体病的发病机理提供科学理论依据。1…     

Parasitological and Clinico‐pathological Profiles in Friesian Cattle Naturally Infected with Theileria annulata in Saudi Arabia

Clinico‐pathological profiles were studied in adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim Region, Saudi Arabia. Sixty‐two clinical cases of T. annulata infection in adult and young Friesian cattle were diagnosed during the period from August 1999 to July 2000. Symptoms observed were marked fever, swelling of superficial lymph nodes, inappetance, tachycardia, dyspnoea and weakness. The most prominent gross pathological features were jaundice, petechial and ecchymotic haemorrhages involving mucosal and serosal surfaces of many organs as well as body fat. A number of young and adult Friesian cattle undergoing lethal T. annulata infection developed lymphoma‐like lesions in a manner similar to that of T. parva. The main histological findings were necrosis and severe lymphocytic infiltration. The spleen, lymph nodes and Peyer's patches were devoid of typical lymph nodules.     

鸭黄病毒感染病例的病理组织学观察

为了探明湖北省肉种鸭和蛋鸭产蛋下降的原因,对引起产蛋下降的病鸭的卵巢中分离的病毒的目的基因进行测序,对3代接种的SPF鸡胚尿囊液进行电镜观察,对脑等组织进行组织病理学观察。序列分析结果表明,扩增的序列属于黄病毒的NS5基因,且与恩塔亚病毒群有相近的遗传进化关系。电镜可观察到40nm～60nm的有囊膜的病毒粒子。组织病理学观察发现输卵管出现严重的充血、出血和炎性反应,脑充血、炎性反应,心脏中有大量变性坏死的炎性细胞。     

The Use of Case History Studies to Differentiate Potentially Infected from Potentially Noninfected Herds with Reactors to Brucella abortus Antigens

Data on farm characteristics and the results of the first herd test for brucellosis were collected for 74 reactor and 74 negative herds in Wellington County, Ontario. Each reactor herd was classified as either probably infected or probably not infected using the occurrence of abortions prior to the first herd test or during the testing period, the total number of cattle removed and/or the spread of reactors within the herd as criteria of infection.     

口蹄疫自然感染动物与免疫动物鉴别诊断研究进展

口蹄疫是偶蹄动物高度接触性传染病 ,能引起巨大经济损失。国际兽医局将其列为 A类动物传染病之首。除发达国家外 ,大多数发展中国家都采用注射疫苗的办法来控制该病的流行。因此如何区分感染动物和免疫动物是口蹄疫防制中迫切需要解决的问题。目前口蹄疫灭活疫苗的生产工艺可以将绝大部分的非结构蛋白除去 ,因而灭活疫苗免疫动物只能产生结构蛋白抗体 ,而感染动物能产生结构蛋白抗体 ,也能产生非结构蛋白抗体 ,因此 ,检测非结构蛋白抗体为鉴别口蹄疫感染动物与免疫动物提供了美好前景。文章从鉴别诊断的原理 ,非结构蛋白的免疫特性 ,鉴别诊断所面临的问题及解决方案 ,应用非结构蛋白作为鉴别诊断抗原的研究现状等方面进行了综述。     

Description of the Infection Status in a Norwegian Cattle Herd Naturally Infected by Mycobacterium avium subsp. paratuberculosis

The Norwegian surveillance and control programme for paratuberculosis revealed 8 seroreactors in a single dairy cattle herd that had no clinical signs of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) infection. Paratuberculosis had been a clinical problem in goats several years previously in this herd. All 45 cattle were culled and a thorough investigation of the infection status was conducted by the use of interferon-γ (IFN-γ) immunoassay, measurement of antibodies, and pathological and bacteriological examination.In the IFN-γ immunoassay, 9 animals gave positive results, and 13 were weakly positive, while 19 animals were negative. In the serological test,10 animals showed positive reactions, and 5 were doubtful, while 30 animals gave negative reactions. There appeared to be a weak trend toward younger animals having raised IFN-γ and older animals having raised serological tests. Histopathological lesions compatible with paratuberculosis were diagnosed in 4 animals aged between 4 and 9 years. Three of these animals had positive serological reaction and one animal gave also positive results in the IFN-γ immunoassay. Infection was confirmed by isolation of M. a. paratuberculosis from 2 of these 4 animals. One single bacterial isolate examined by restriction fragment length polymorphism (RFLP) had the same profile, B-C1, as a strain that had been isolated from a goat at the same farm several years previously.Despite many animals being positive in one or both of the immunological tests, indicative of a heavily infected herd, none of the animals showed clinical signs and only one cow was shown to be shedding bacteria. A cross-reaction with other mycobacteria might have caused some of the immunoreactions in these animals. It is also possible that the Norwegian red cattle breed is resistant to clinical infection with M. a. paratuberculosis.     

用口蹄疫病毒非结构蛋白鉴别感染动物与疫苗免疫接种动物

口蹄疫是由口蹄疫病毒引起的发生于偶蹄类动物的一种急性、热性传染病,曾多次在世界上发生过大流行。疫苗接种是防控口蹄疫暴发的有效措施之一,而要控制口蹄疫的流行,首先要将病毒感染动物从疫苗接种群体中区分开来。以口蹄疫病毒非结构蛋白(NSPs)为抗原,分别利用口蹄疫病毒非结构蛋白2C、3B、3AB和3ABC作为鉴别诊断抗原,检测动物体内的NSPs抗体,可有效的区分感染动物与疫苗免疫接种动物。目前,许多实验室已展开此项工作的研究,这为防控口蹄疫打下了良好的基础。     

绵羊慢病毒自然感染绵羊的硬化性淋巴细胞性乳腺炎

７头来自新疆南部某绵羊慢病毒（ＯｖＬＶ）感染的羊场的绵羊用于本研究。用琼脂凝胶免疫扩散检查绵羊血清中对绵羊进行性肺炎（ＯＰＰ）病毒（ＯＰＰＶ）的抗体，结果表明有６例呈阳性，１例阴性，抗体效价在３年中呈下降趋势。４例血清学阳性边菜羊和１例阴性和田羊有不同程度的硬化性（纤维性）淋巴细胞性乳腺炎，小叶内有不等的淋巴细胞浸润，导管周围无淋巴滤泡形成，小叶间大量纤维组织增生。７例的肺、脑、关节、血管均无ＯｖＬＶ性特异性病变。从血清学阳性羊的外周血白细胞中未分离到ＯｖＬＶ。