宁夏吴忠地区规模化奶牛场流产牛病原血清学调查

为了调查宁夏吴忠地区奶牛场因传染性因素造成流产的基本情况,应用酶联免疫吸附试验(ELISA)对可能造成感染流产的牛传染性鼻气管炎病毒、新孢子虫、牛病毒性腹泻病毒的抗体及布鲁菌的抗原进行了血清学检测。结果显示,牛传染性鼻气管炎病毒抗体阳性率为48.84%,新孢子虫抗体阳性率为30.23%,牛病毒性腹泻病毒抗体阳性率为19.77%,布鲁菌抗原阳性率为24.42%。牛场阳性率高达100%。根据统计显示,不同妊娠胎次的奶牛流产率差异显著(P0.05),其中第1胎流产率与其他胎次间差异极显著(P0.01)。不同妊娠时间的奶牛流产率差异不显著(P0.05)。调查表明,宁夏部分奶牛场存在不同程度的牛传染性鼻气管炎病毒、新孢子虫、牛病毒性腹泻病毒和布鲁菌感染。     

狂犬病病毒流行病学特征与实验室诊断技术的研究进展

狂犬病是由狂犬病病毒引起的以中枢神经系统感染为特征的一种人兽共患病。狂犬病病毒具有嗜神经性,能在人和多种哺乳动物中引起致死性感染,病死率几乎为100%。除常规的临床诊断外,狂犬病的确诊依赖于实验室诊断方法,方法主要有病原学诊断、血清学诊断和分子生物学诊断方法等。狂犬病作为一种人兽共患烈性传染病,呈全球分布的态势,中国每年因狂犬病病毒感染而导致死亡的人数居全球第2位。因此,加强对该病的病原学、流行病学特征的认识、加快实验室诊断方法的研究对其综合防控工作具有十分重要的意义。作者主要介绍了目前国内外狂犬病流行病学特征和诊断方法的研究进展,并比较了各种方法的优点和缺点,为狂犬病的临床快速诊断和深入研究提供科学依据。     

河南省奶牛病毒性腹泻-黏膜病血清学调查

摘要： 为了解河南省奶牛病毒性腹-黏膜病的发生情况,2009年5月对河南省的豫东、豫西、豫南、豫北和郑州市五区域20个奶牛小区的355头奶牛,随机采血,采用ELISA方法,检测奶牛病毒性腹泻-黏膜病血清抗体,结果显示20个奶牛小区有17个奶牛小区感染有病毒性腹泻-黏膜病病毒,场感染率为85%,各小区奶牛病毒性腹泻-黏膜病检测阳性率在0-88.24%,血清阳性率平均为53.8%,表明该病在河南省奶牛中感染率较高。     

新疆几种花卉病毒的鉴定

对所采集的百日菊、美人蕉、唐昌蒲病毒病的毒源标样,经鉴别寄主反应、电镜观察、物化属性测定、蚜传试验、种(球)传试验及血清学反应,百日菊的病原病毒鉴定为:黄瓜花叶病毒(CMV)、烟草花叶病毒(TMV)、番茄不孕病毒(TAV)、蚕豆萎蔫病毒(BBWV)。其中以 CMV 为主,约占64％。4种病毒均可通过汁液摩擦接种,不经种传。美人蕉病原病毒鉴定为黄瓜花叶病毒。其块根带毒率达45％以上。唐昌蒲病原病毒经鉴定为黄瓜花叶病毒。其球茎带毒率可达45％以上。     

Optimisation of sample size for the detection of latent infection byRalstonia solanacearum in potato seed tubers in the highlands of Peru

Summary A sampling strategy was evaluated in the Andean highlands of Peru to optimise the detection ofRalstonia solanacearum in seed tubers harvested from symptomless crops. A sensitive and specific serological method developed at CIP was used to detect the pathogen in latently infected tubers. Optimum sample size was evaluated for symptomless crops after analysing various numbers of composite samples and using a binomial distribution model to calculate the detection probabilities.R. solanacearum was detected in all lots from fields with visible symptoms, so validating the detection technique. About half of the seed lots from apparently healthy fields at altitudes of up to 3,100 m were found positive for the pathogen.R. solanacearum was detected with 99% probability in samples of 350 tubers from seed lots from symptomless crops. This number of seed tubers could feasibly be processed in a seed-health test without incurring too high a cost for labour and materials.     

奶牛布鲁氏菌病的诊断

对某养牛小区5头流产等疑似布鲁氏菌病奶牛的病料和血清分别进行微生物学诊断和血清学诊断,结果 5份病料中分离出2株布鲁氏菌,5份血清全部呈阳性,阳性率100%。试验结果表明,该养牛小区的奶牛流产原因是布鲁氏菌病所致,牛群中流行布鲁氏菌病,必须有效控制该病的进一步发展和蔓延。     

Comparing recombinant MPB70/SahH and native 20-kDa protein for detecting bovine tuberculosis using ELISA

Bovine tuberculosis (bTB) is a zoonosis caused by Mycobacterium bovis. Test-and-cull protocols and gross pathological examinations of abattoir animals as well as milk pasteurization have been implemented to prevent the spread of tuberculosis from animals to humans worldwide. Despite the importance of precise and rapid diagnostic tests, conventional methods including intradermal skin tests and γ-interferon assays are limited by the high rate of false-negative results for cattle in the late infectious stage and due to laborious and time-consuming procedures. Therefore, antibody detection methods such as enzyme-linked immunosorbent assay (ELISA) are urgently needed to supplement the established approaches and expand the diagnostic window. This study was conducted to develop a bTB ELISA by evaluating recombinant and native proteins and various assay parameters. We produced recombinant MPB70 and SahH (M70S) and a native 20-kDa protein (20K) and optimized the ELISA protocol. The 20K ELISA showed 94.4% sensitivity and 98.2% specificity with an optimal sample-to-positive ratio cut-off of 0.531. The sensitivity and specificity of M70S ELISA were 94.4% and 97.3%, respectively, with an optimal sample-to-negative ratio cut-off of 1.696. Both assays showed acceptable diagnostic efficiency and could be used for bTB diagnosis in combination with established methods for herd screening and to expand the diagnostic window.     

Performance of skin tests with allergens from B. melitensis B115 and rough B. abortus mutants for diagnosing swine brucellosis

Swine brucellosis by Brucella suis biovar 2 is an emerging disease whose control is based on serological testing and culling. However, current serological tests detect antibodies to the O-polysaccharide (O/PS) moiety of Brucella smooth lipopolysaccharide (S-LPS), and thus lack specificity when infections by Yersinia enterocolitica O:9 and other gram-negative bacteria carrying cross-reacting O/PS occur. The skin test with the protein-rich brucellin extract obtained from rough B. melitensis B115 is assumed to be specific for discriminating these false positive serological reactions (FPSR). However, B115 strain, although unable to synthesize S-LPS, accumulates O/PS internally, which could cause diagnostic problems. Since the brucellin skin test has been seldom used in pigs and FPSR are common in these animals, we assessed its performance using cytosoluble protein extracts obtained from B. abortus rough mutants in manBcore or per genes (critical for O/PS biosynthesis) and B. melitensis B115. The diagnostic sensitivity and specificity were determined in B. suis biovar 2 culture positive and brucellosis free sows, and apparent prevalence in sows of unknown individual bacteriological and serological status belonging to B. suis biovar 2 naturally infected herds. Moreover, the specificity in discriminating brucellosis from FPSR was assessed in brucellosis free boars showing FPSR. The skin test with B. abortus ΔmanBcore and B. melitensis B115 allergens performed similarly, and the former one resulted in 100% specificity when testing animals showing FPSR in indirect ELISA, Rose Bengal and complement fixation serological tests. We conclude that O/PS-free genetically defined mutants represent an appropriate alternative to obtain Brucella protein extracts for diagnosing swine brucellosis.     

云南省楚雄州部分地区猪瘟血清学调查

为了解楚雄州部分地区的猪瘟免疫情况,利用酶联免疫法（ELISA）对楚雄市、南华县和禄丰县随机采取的393份血清进行猪瘟抗体检测,并对各县（市）的调查数据加以比较,了解猪瘟在楚雄州部分地区的免疫情况。结果显示,楚雄州部分地区均有较高的猪瘟抗体阳性率,各县（市）的猪瘟抗体阳性率都在80％以上,有的县（市）猪瘟抗体甚至达到了100％。说明楚雄州部分地区的猪瘟免疫效果较好,猪瘟免疫成功。     

高原奶牛布鲁氏菌病的血清学调查

为了解青海省民和县奶牛布鲁氏菌病的分布和流行情况,净化布鲁氏菌病,对来自12个乡镇的10308份奶牛血清采用试管凝集反应试验(SAT)进行了血清学检测,检出阳性血清23份,阳性率为0.223%,表明青海民和地区存在奶牛布鲁氏菌的感染。