牛冠状病毒灭活疫苗的免疫效力试验

为了评价制备的牛冠状病毒灭活疫苗的免疫效力,试验选用分离鉴定出来的牛冠状病毒(BCV-YC分离株)为制苗种毒,接种HRT-18细胞进行增殖,收集上清液进行超速离心浓缩,最后加入甲醛灭活制成油乳剂灭活疫苗,分别接种小鼠和妊娠母牛。结果表明,疫苗不仅使小鼠具有一定的保护力,而且使妊娠母牛也能产生较高的抗体水平,犊牛攻毒试验证明,产生的母源抗体能使初生犊牛抵抗牛冠状病毒的攻击。说明制备的牛冠状病毒灭活疫苗对抵抗牛冠状病毒感染具有良好的保护性。     

牛支原体灭活疫苗免疫小鼠最小免疫剂量及抗体消长规律研究

[目的]对小白鼠进行最小免疫剂量及抗体消长规律初步研究。[方法]采用课题组制备的牛支原体灭活氢氧化铝佐剂疫苗,分别以0.1 mL/只·天、0.2 mL/只·天、0.3 mL/只·天、0.4 mL/只·天的不同剂量,注射小白鼠腿部肌肉。[结果]最小免疫剂量为0.2 mL/只;免疫3周后抗体滴度达到最高峰,随后抗体滴度开始逐步下降,但仍保持相对稳定,抗体滴度维持在0.319的较高水平,5周后抗体滴度表现明显下降趋势。[结论]本试验为后期牛支原体灭活疫苗在牛群中进行试验研究奠定了基础。     

温氏支原体感染动物模型的建立

为促进温氏支原体的深入研究,本试验建立了温氏支原体感染动物模型。选择6～8周龄健康雄性昆明种小鼠60只,随机分为A、B、C、D 4组,试验组(A、B、C)分别以不同方式感染温氏支原体,D组为对照组。结果表明,腹腔注射一定剂量高感染强度的牛红细胞悬液,同时注射免疫抑制剂地塞米松组(C组)表现为首现期出现早,且高峰期红细胞感染率高。应用悬滴镜检法和PCR诊断方法对感染小鼠血样进行鉴定,均符合温氏支原体特征。选择对照组小鼠和感染率高、临床症状较为明显的C组小鼠各10只,进行血液生理生化指标测定(RBC、WBC、Hb、TP、G、ALT、AST),结果呈现出与牛感染温氏支原体相同的规律。     

不同厂家猪肺炎支原体灭活疫苗免疫效力对比实验

本研究旨在评价不同厂家猪肺炎支原体灭活疫苗的免疫攻毒保护效果。选择4周龄仔猪25头,随机分为5组,每组5头猪,分别免疫四种猪肺炎支原体灭活疫苗（即疫苗A组、疫苗B组、疫苗C组、疫苗D组）,E组为攻毒对照组,不做任何处理,在同等条件下隔离饲养。各疫苗按照对应的说明书进行免疫,免疫后第14、28天进行采血,检测支原体抗体水平,一免后28 d时,所有免疫组连同攻毒对照组,各气管注射猪肺炎支原体CJ株5 m L/头（含0.01 g肺组织毒）。攻毒后饲养观察28 d,对所有实验组动物进行观察临床症状。A组实验动物攻毒后未出现咳嗽、腹式呼吸等支原体临床症状,B-D组实验猪攻毒后偶尔出现轻微间隔性咳嗽,E组实验动物攻毒后出现连续性咳嗽,个别猪出现腹式呼吸等临床症状。攻毒后第28天进行病理剖检。结果表明,攻毒对照组猪4/5头出现典型猪肺炎支原体病变,在肺脏尖叶、心叶、膈叶前1/3部位以及中间叶,出现“肉样”或“胰样”实质样病变,界限明显。B～D组解剖后个别猪出现典型猪肺炎支原体病变,A组实验动物解剖后个别猪肺脏出现零星病变,剩余实验动物肺脏均未出现猪肺炎支原体病变。根据肺部病变较少率计算,A～D组病变...     

动物模型在荷斯坦牛遗传评定上的应用

本研究应用动物模型ＢＬＵＰ法在微机上评定了北京地区１９６５￣１９９２年间出生的荷斯坦牛４１０８０头，建立了一套荷斯坦牛的动物模型评定系统。迭代求解采用间接解法，在阅读数据文件时进行。对于管理组、公牛与牛场互作、永久环境效应，采用Ｇａｕｓｓ－Ｓｅｉｄｅｌ迭代法，对于动物个体和遗传组效应，采用不完全的Ｊａｃｏｂｉ迭代法。提供预期传递力、父母传递力均数、预期生产力、表型均值等有用的遗传和生产信息。在配备     

猪肺炎支原体灭活疫苗的实验室效力研究

为了探究自主研制的猪肺炎支原体灭活疫苗的实验室免疫效力,为临床应用提供科学依据,试验分别用2.0 mL/头、1.0 mL/头、0.5 mL/头和0.25 mL/头4种剂量的试验疫苗两次免疫7～14日龄健康仔猪,通过测定免疫期间猪只生长情况、抗体水平变化情况及肺脏病变指数等,以确定该疫苗的最小免疫剂量及其安全性.结果表明...     

猪支原体肺炎灭活疫苗的免疫效果研究

对猪肺炎支原体（J株）进行培养后,采用新型工艺制备了4批猪支原体肺炎灭活疫苗。并对疫苗进行了安全性、免疫效果、免疫期检验。结果表明该灭活疫苗对猪安全有效,并且可使免疫猪的肺炎减少率达到75％以上,免疫期可达到6个月以上。     

应用灭活疫苗防制牛白血病病毒感染

检测了用感染牛白血病病毒（ＢＬＶ）的ＬＫ１５细胞系（ＬＫ１５疫苗）或蝙蝠肺细胞系（Ｂａｔ疫苗）制备的苗对牛的保护作用。１２头牛间隔４周免疫接种２次，然后于第２次接苗后４周攻毒，用ＬＫ１５疫苗接种的９头牛产生了ＢＬＶ特异性糖蛋白（ｇｐ）抗体，其琼扩试验效价为１：１６～１：６４。用１００μ１（含７０～１００个合胞体）ＢＬＶ持续感染奶牛血液攻击的４头牛均获得保护。其余５头牛用５００μ１感染牛血液攻毒，仅     

鸡滑液囊支原体致病模型建立与灭活疫苗免疫效果评价

为科学评价鸡滑液囊支原体(MS)灭活疫苗的免疫效果,本试验选用3株田间流行的MS菌株(LHMS07、LHMS105和LHMS106),通过爪垫、静脉、气囊注射3种途径和不同攻毒剂量摸索建立SPF鸡攻毒致病模型的方法,并以建立的模型为基础,于攻毒后21 d根据临床病变评分和爪垫肿胀鸡只比例综合评价A和B两种商品化灭活疫苗的免疫效果。结果显示,本试验所建立的攻毒模型为SPF鸡爪垫注射0.2×10⁵CCU的LHMS106菌株,该模型可致试验鸡爪垫肿胀率达100%;疫苗效果评价试验中,攻毒对照鸡只临床病变评分均值为3.4分,爪垫肿胀鸡只比例高达100%;A疫苗和B疫苗免疫后,鸡只临床病变评分均值分别降低至0.5分和1.0分,爪垫肿胀鸡只比例分别降低至12.5%和37.5%。结果表明,养殖场需要科学选择MS灭活疫苗,尤其需要以流行的强菌株建立相对稳定可靠的攻毒模型进行免疫保护效果评价。     

牛支原体间接免疫酶标组织化学检测方法的建立

为建立检测牛支原体的间接免疫组织化学(简称免疫组化)方法,分别以鸡抗牛支原体(Mycoplasma bovis)IgY、羊抗鸡IgG-HRP为一抗和二抗,对牛支原体菌体涂片和牛支原体阳性肺脏组织切片进行免疫组化染色,并对染色条件进行优化,确定组织触片及组织切片的最佳免疫组化条件。在最佳条件下对病死犊牛病料切片进行免疫组化检测,并以细菌分离培养和PCR方法进行验证。结果显示,免疫组化法阳性标本与分离培养和PCR结果相符,而阴性对照和替代试验均为阴性。结果表明本试验建立的间接免疫组化方法可用于检测临床病例组织样本及培养物中的牛支原体,具有特异性和可靠性,为探究该病原在机体内的定位、动态分布规律及致病机理提供了手段。     

Examination of the role of Mycoplasma bovis in bovine pneumonia and a mathematical model for its evaluation

The authors screened 34 large cattle herds for the presence of Mycoplasma bovis infection by examining slaughtered cattle for macroscopic lung lesions, by culturing M. bovis from lung lesions and at the same time by testing sera for the presence of antibodies against M. bovis. Among the 595 cattle examined, 33.9% had pneumonic lesions, mycoplasmas were isolated from 59.9% of pneumonic lung samples, and 10.9% of sera from those animals contained antibodies to M. bovis. In 25.2% of the cases M. bovis was isolated from lungs with no macroscopic lesions. The proportion of seropositive herds was 64.7%. The average seropositivity rate of individuals was 11.3% but in certain herds it exceeded 50%. A probability model was developed for examining the relationship among the occurrence of pneumonia, the isolation of M. bovis from the lungs and the presence of M. bovis specific antibodies in sera.     

肠炎沙门氏菌灭活苗制作和应用

肠炎沙门氏菌属于无宿主特异性而有侵害性的病原菌之一，宿主包括人和各种动物。该菌不仅能引起家禽发病死亡造成严重的经济损失，而且被污染的家禽产品作为肠炎沙门氏菌的携带者，还严重危害人类健康。据报道，日、美等发达国家发生的食物中毒事件中40％～80％是由禽沙门氏菌引起的，其中主要病原为肠炎沙门氏菌(S G Mellroy，et al．1989)。由肠炎沙门氏菌引起人的急性胃肠炎(食物中毒)，在世界各国有增加的趋势，     

牛支原体TaqMan探针实时荧光定量PCR检测方法的建立及应用

以牛支原体p80基因为靶基因,设计特异性引物与探针,优化反应体系,建立了牛支原体TaqMan探针实时荧光定量PCR(TaqMan real-time PCR)检测方法,并对该方法进行了特异性、敏感性、重复性评估以及临床样本检测。结果显示,特异性试验中,牛支原体2个菌株Cq值均小于18,其余13个非牛支原体菌株Cq值均大于36;敏感性试验中,最低可检3.89拷贝/μL靶DNA,是普通PCR的10~4倍(普通PCR 3.89×10~4拷贝/μL);重复性试验中,组内、组间重复的变异系数均小于1%;44份牛的临床样品利用TaqMan real time PCR检出6份阳性(阳性率为13.64%),分离培养鉴定检出7份阳性,普通PCR检测全部阴性。本研究建立了一种敏感、特异、稳定的牛支原体TaqMan real time PCR检测方法,可用于牛支原体的快速诊断和核酸定量检测。     

乳牛衣原体病灭活疫苗效检小鼠模型的建立

为了解决以本动物效检乳牛衣原体病灭活疫苗成本高的问题，用11批乳牛衣原体病灭活疫苗做乳牛效力试验时同步做小鼠效力试验，除第3批次疫苗的本动物效检结果与小鼠效检结果略有差异外，其他批次疫苗的效检结果均一致。结果表明，用小鼠做牛衣原体灭活疫苗的效检动物模型是可行的。     

A field study of Mycoplasma bovis infection in cattle

After an outbreak of mastitis in cattle caused by Mycoplasma bovis a study was made in 5 herds with recent cases (principal herds) and in 4 control herds. In the principal herds, M. bovis was isolated from milk samples, nasal swabs, and from one vaginal swab. M. bovis was also isolated from nasal swabs of calves in 2 of the 4 control herds, whereas all milk samples and vaginal swabs from the control herds were negative. Evaluation of serum antibody titres to M. bovis among non-mastitic animals of 3 principal herds and 1 control herd showed no difference in distribution of the titre values, which generally were low. However, cows excreting M. bovis in the milk had high antibody titres. The way of introduction to the herds and the spread of the infection within the herds could not be established by the study, which was supplemented by a DNA restriction fragment analysis of a number of M. bovis isolates.     

Evaluation of Mycoplasma hyopneumoniae inactivated vaccine in pigs under field conditions

An inactivated vaccine prepared from broth culture supernatant of Mycoplasma hyopneumoniae with an aluminum adjuvant was evaluated in three herds (herd A: specific pathogen-free herd, herd B: high health status herd with no clinical signs of respiratory infection, herd C: low health status herd with serious epidemiological and economical problems). A total of 212 pigs from the three herds were divided into two groups. One group was injected twice with the vaccine at 4-week intervals and the other was a control group. No adverse reactions were noted following the vaccinations either systematically or locally in any of the vaccinated pigs from any of the herds. In herd A, the vaccination provided antibody response within 4 weeks after the second vaccination and antibody responses continued for more than 12 weeks. In herds B and C, the number of pigs with lung lesions, mean percentage of lung lesions, and the numbers of M. hyopneumoniae recovered from pigs at slaughter in the vaccinated group were significantly (P < 0.05) reduced compared to the control group. Furthermore, vaccination resulted in improved average daily weight gain (ADG), improved feed conversion ratio (FCR), and improved days to market weight in herd C, whereas no difference in growth performance was shown in herd B. It is suggested that the inactivated vaccine prepared from broth culture supernatant of M. hyopneumoniae is effective in reducing clinical signs and lung lesions. Also, vaccination resulted in improved growth performance in herds where clinical signs and economic losses were significant.