口蹄疫A型病毒AF/72株特异性鉴定及其豚鼠标准血清的制备

用口蹄疫A型病毒AF/72株的细胞毒AF/72/MF6/BF12,经测定其TCID50为108.0/ml;经RT-PCR获得其VP1基因序列,并与GenBank中的其他7株口蹄疫A型病毒株比对,同源性均大于85%;经间接夹心ELISA测定,OD值均大于0.2,且该毒仅能被口蹄疫A型标准血清中和,具有型特异性;经紫外分光光度法测定其146S含量,均值为189 ng/ml,远大于22 ng/ml的国际标准.将此细胞毒与弗氏佐剂联合制成灭活疫苗免疫豚鼠后分离血清,经无菌检验和外源病毒检验,纯净性达到兽用生物制品标准要求;经ELISA检测此血清的抗体滴度、原血清、强阳性血清和弱阳性血清的中和效价均远小于1 ∶ 45.参照标准的要求,确定强阳性血清为口蹄疫A型病毒株AF/72的参考血清.     

黔西县几个种猪场生猪疫病血清学调查报告

采用正向间接血凝（IHA）试验随机对3个1000头以上种猪场的90份血清,进行了猪口蹄疫（FMD）、猪瘟（HC）血清学监测;同时还采用一步法猪瘟（HC）、猪繁殖与呼吸综合征（PRRS）疫病病毒反转录（PCR）对血清进行了检测。结果表明,种猪场的FMD、HC免疫合格率分别为85.56%和87.78%,均达到国家农业部规定70.0%的标准;用PCR法检测HC、PRRS阳性检出数为0。     

O型FMDV VP1基因与山羊IL-18基因在昆虫细胞中的共表达与活性检测

以杆状病毒pFastBacTM Dual为载体,将O型口蹄疫病毒(FMDV)VP1基因和山羊白介素18(gIL-18)基因,分别插入到双表达载体的P10启动子和多角体蛋白启动子PH的下游,构建重组质粒pFastBacTMDual-gIL18-VP1,然后转化DH10Bac感受态细胞,经三重抗性与蓝白斑筛选,获得杆状病毒重组质粒Bacmid-gIL18-VP1,并利用昆虫细胞进行转染。间接免疫荧光试验(IFA)检测表明gIL-18基因和VP1基因同时在同一细胞中独立表达。将共表达产物进行生物学活性分析表明,重组蛋白能够诱导山羊脾淋巴细胞生成IFN-γ抑制水疱性口炎病毒(VSV)在牛肾细胞(MDBK)上生长。本试验用Bac-to-Bac系统成功构建了同时含有gIL-18基因和VP1基因的重组杆状病毒,并在昆虫细胞中得到了高效表达,且具有良好的生物学活性,从而为下一步研究gIL-18在口蹄疫(FMD)中的免疫调节作用奠定了坚实的基础。     

口蹄疫纳米乳疫苗免疫持续期的试验研究

试验用同一批次相同抗原含量的口蹄疫病毒灭活抗原,分别采用纳米乳佐剂和ISA206佐剂配制口蹄疫O型、A型双价灭活疫苗,并对仔猪进行免疫,免疫后6个月内用液相阻断ELISA方法检测O型、A型免疫抗体效价(lg)。结果:免疫后6个月内纳米乳疫苗免疫猪产生的抗体lg平均值均高于ISA206佐剂疫苗,抗体水平在免疫后1个月达到最高。免疫后第6个月,纳米乳疫苗O型抗体lg平均值为2.19,A型抗体lg平均值为2.175,按液相阻断ELISA试剂盒的判定标准免疫猪抗体lg≥1.8,具有99%以上保护效力,纳米乳疫苗属于完全保护范围,而ISA206佐剂疫苗属于不完全保护范围。     

Saponin Adjuvants. IV. Evaluation of The Adjuvant Quil a in the Vaccination of Cattle Against Foot-And-Mouth Disease

The saponin adjuvant Quil A has been investigated in the vaccination of cattle against foot-and-mouth disease. Using a Frenkel type vaccine a dose-response relationship has been established between Quil A and neutralizing antibody titres. Ten ml of vaccine was combined with 0, 50, 200, 800, and 3200 µg of Quil A. The combinations were each injected into 4 animals. The local reaction on the site of injection produced by injection of the vaccine alone and in combination with different doses of Quil A has been estimated. On this basis a therapeutical dose at 1 mg of Quil A has been estimated to combine maximum adjuvant effect with a minimum of adverse reactions. This dose has been tested in the vaccination of cattle with FMD vaccines derived from BHK suspension cell virus of type O and A respectively. The vaccines were tested in 10 ml and 5 ml doses with or without Quil A, and each in 4 animals. It is concluded that Quil A is a valuable adjuvant for use in the induction of neutralizing antibodies against foot-and-mouth disease in cattle.     

Foot and mouth disease in the Borana pastoral system,southern Ethiopia and implications for livelihoods and international trade

Participatory epidemiology (PE) was used on the Borana plateau of southern Ethiopia to understand pastoralist’s perceptions of the clinical and epidemiological features of foot and mouth disease (FMD) in cattle. Matrix scoring showed good agreement between informant groups on the clinical signs of acute and chronic FMD, and findings were cross-checked by clinical examination of cattle and assessment of previous clinical FMD at herd level by detection of antibody to non structural proteins of FMD virus. The positive predictive value of pastoralist’s diagnosis of FMD at herd level was 93.1%. The annual age-specific incidence and mortality of acute FMD in 50 herds was estimated using proportional piling. The estimated mean incidence of acute FMD varied from in 18.5% in cattle less than two years of age to 14.0% in cattle three to four years of age. The estimated mean mortality due to acute FMD varied from 2.8% in cattle less than two years of age to 0.3% in cattle three of age or older. Pearson correlation coefficients for acute FMD by age group were −0.12 (p > 0.05) for incidence and −0.59 (p < 0.001) for mortality. Estimates of the annual incidence of chronic FMD varied from 0.2% in cattle less than two years of age to 1.8% in cattle three to four years of age. The Pearson correlation coefficient for the incidence of chronic FMD by age group was 0.47 (p < 0.001). Outbreaks of FMD peaked in Borana cattle during the two dry seasons and were attributed to increased cattle movement to dry season grazing areas. The mean seroprevalence of FMD was estimated at 21% (n = 920) and 55.2% of herds (n = 116) tested seropositive. Serotyping of 120 seropositive samples indicated serotypes O (99.2%), A (95.8%), SAT 2 (80%) and C (67.5%). The endemic nature of FMD in Borana pastoral herds is discussed in terms of the direct household-level impact of the disease, and the increasing export of cattle and chilled beef from Ethiopia.     

贵阳地区家畜口蹄疫免疫抗体监测结果分析

采用LB—ELISA方法对贵阳地区6个种畜场、8个规模养殖场、11户农村散养户和5个屠宰场迭检的826份血清样本进行口蹄疫免疫抗体检测，结果表明：贵阳市家畜口蹄疫免疫抗体的平均合格率为84．6％，达到农业部要求。其中种畜场口蹄疫免疫抗体的平均合格率为97．1％，规模养殖场为92．19，5，农村散养户为72．79，5，屠宰场为63．79，5，免疫抗体合格率的总体趋势为种畜场〉规模场〉散养户〉屠宰场。     

Healed long-bone fractures in wild birds

AIM: To build a profi le of the oral lesions that occur in sheep in New Zealand that need to be considered within the differential diagnosis of foot-and-mouth disease.

METHODS: Lesions of the anterior lips and gums of sheep were surveyed in two abattoirs, photographed, and described grossly and histopathologically.

RESULTS: A sequence of lesions in order of age and stage of healing are described and illustrated, and their pathogenesis discussed. Lesions of the midline of the lips and gums of traumatic or irritant aetiology were common, and the prevalence was higher in adult sheep than in lambs.

CONCLUSIONS: The majority of lesions observed appeared to be primarily of traumatic aetiology. They probably arose from the fright/flight response behaviour of sheep, resulting in the mouth impacting against wire fences or yard railings while being handled. A smaller percentage of lesions may have been due to abrasive or irritant feed or soil. The presence of plant material and bacteria in lesions delayed healing and contributed to the formation of ulcers.     

口蹄疫灭活疫苗中蛋白质含量测定方法的比较

口蹄疫灭活疫苗中蛋白质含量的测定,可以反映出疫苗生产工艺的优劣以及疫苗质量。采用凯氏定氮法、改良Lowry法和考马斯亮蓝法三种较常见的蛋白质含量测定方法,对全国六个不同口蹄疫灭活疫苗生厂家共计15批疫苗的总蛋白质含量进行测定,并对测定结果进行比较,同时采用SDS—PAGE对样品中蛋白质含量进行定性,验证以上三种方法测定结果。结果表明,这些疫苗的总蛋白质含量差异比较大,1mL水相样中蛋白质含量在50—2000μg范围内。三种检测方法比较表明,改良Lowry法能较真实的反映口蹄疫灭活疫苗中蛋白质含量;与凯氏定氮法相比,此方法操作简单,工作效率高,而且低耗。     

高效体积排阻色谱检测口蹄疫灭活疫苗中146S抗原含量的疫苗前处理方法比较

为提高高效体积排阻色谱检测口蹄疫灭活疫苗146S抗原含量的准确性、适用性和操作性,分别采用正戊醇、正丁醇和三氯甲烷对9批口蹄疫灭活疫苗进行破乳处理,对三种方法的破乳后水相得率和146S抗原含量的色谱检测结果进行比较。结果表明,破乳后水相得率分别为:正戊醇38%~49%,正丁醇42%~44%,三氯甲烷50%;9批疫苗的色谱结果均检测到146S特征峰,146S含量在0.7~12.5μg/mL,3次测定的相对标准偏差最大值为4.0%,9批疫苗不同前处理方法的检测结果均值具有统计学意义,三氯甲烷组与正戊醇组数据一致性强,正丁醇组测定值偏低。使用三氯甲烷对疫苗进行破乳,不仅操作简便快速,而且破乳水相得率稳定,是最优的破乳方法。实验进一步优化了口蹄疫灭活疫苗146S抗原含量检测的高效体积排阻色谱法,为该方法的科学应用提供了数据支撑。