中国株猪瘟兔化弱毒克隆毒的研究

采用终点稀释单细胞微量培养法对中国株猪瘟哆化弱毒（Ｃ株）进行克隆,获１０个克隆株;保持原Ｃ株的免疫原性和其他优良特性;在某些方面并有所提高。随机取６号克隆毒（Ｃ６）进行系列试验,结果表明：（１）对牛睾丸细胞敏感,共收毒批次和合格批次为１５／１９（７９．９％）（２）用兔增殖毒共归兔６４只,发率为９０．６％,用睾丸细胞增殖毒对３８只兔热反应率为８９．４７％,（３）按“规程”安检和增大一倍量对猪均无不良     

关于猪瘟兔化弱毒疫苗的探讨

猪瘟作为一种严重危害养猪业的毁灭性传染病,为畜牧业的发展造成了一定的阻碍,猪瘟病毒兔化弱毒株具有优良的免疫原性,在我国使用比较广泛.文章探讨了猪瘟兔化弱毒疫苗的生物学特性,包括其遗传特性、对猪的免疫原性、对猪的安全性,猪瘟兔化弱毒疫苗的应用.     

猪瘟兔化弱毒疫苗胎盘传递感染试验

对怀孕40－54天16头和怀孕65－92天28头经产母猪以4头份猪瘟兔化弱毒疫苗进行免疫接种。44头母猪都正常分娩,所产仔猪在两个月内生长发育正常,从免疫猪所产29窝仔猪中各抽取2头,取其脾脏,用生理盐水制成1：10乳剂,每窝仔猪脾乳剂注射家兔2－4只进行疫苗 回收试验,结果,从怀孕40－54天接苗组的一窝仔猪脾乳剂中回收到疫苗株。     

猪瘟兔化弱毒疫苗的研究概况

猪瘟病毒兔化弱毒株因其优良的免疫原性,成为我国至今唯一使用的猪瘟疫苗株。本文就猪瘟兔化弱毒株的生物学特性、猪瘟兔化弱毒组织疫苗和细胞疫苗的研制以及疫苗的应用进行了综述。     

齐卡肉兔接种猪瘟兔化弱毒(C株)的热型观察

为了查找生产中原料兔接种猪瘟兔化弱毒C株病毒后定型热比例常低于70%的原因,观察了无猪瘟病毒抗体的8个批次,共3 512只中型齐卡肉兔对猪瘟兔化弱毒C株病毒的热型反应。结果:定型热占(91.3±1.5)%,轻热(5.8±1.2)%,可疑(1.8±1.5)%,无反应(0.9±0.7)%;8个批次的试验兔,对5个毒种代次的体温反应,差异不显著(P0.05)。研究认为,来自农村养兔户的原料兔,可能接触过猪瘟病毒,致定型热比例下降;无猪瘟抗体的中型齐卡肉兔,对不同代次的猪瘟兔化弱毒C株病毒均有良好的体温反应,可作为猪瘟弱毒疫苗(脾淋源)的原料兔。     

猪瘟病毒野毒株和兔化弱毒疫苗株RT-PCR-RFLP鉴别检测方法的建立

本研究旨在建立猪瘟病毒野毒株和兔化弱毒疫苗株RT-PCR-RFLP鉴别检测方法。根据Shimen株设计1对特异性引物,建立猪瘟病毒RT-PCR-RFLP检测方法;对20份疑似猪瘟临床样品进行检测,并对检出的山东8株流行野毒株和2株疫苗株PCR产物进行克隆与序列分析,验证上述方法。结果RT-PCR扩增片段为825bp,产物经RFLP分析,野毒株的PCR产物能被ApaⅠ酶切为322bp和503bp 2个片段,兔化弱毒疫苗株则不能被酶切,检测出RNA的最低浓度为0.028 6μg.mL-1;8株流行野毒株都含GGGCCC序列(ApaⅠ酶切位点),2株疫苗株相应序列为GAGCCC,不能被ApaⅠ酶切;8株流行野毒株属于基因2群,2株疫苗株与HCLV遗传关系近,为基因1群。建立了可鉴别猪瘟病毒野毒株和兔化弱毒疫苗株RT-PCR-RFLP检测方法,为猪瘟的防控提供有效手段。     

猪瘟兔化弱毒疫苗与我国近年猪瘟野毒的免疫保护相关性试验

２批猪瘟兔化毒睾丸细胞苗分别来自两家兽医生物药品厂，各分别免疫接种猪只，随后以５株猪瘟病毒野毒分别攻击，疫苗接种猪完全存活，对照猪完全死亡。此５株野毒分离自国内不同地区，并皆已经过细致的鉴定，以免疫荧光技术对猪扁桃体进行了活体检查，各对照猪材料上能在攻击后一周时出现病毒，而疫苗接种猪在整个观察期间未出现病毒，据此，显然可见猪瘟兔化毒细胞苗在预防国内猪瘟上极有效力     

中国猪瘟C-株(脾淋毒)全长cDNA的分子克隆

应用RT-PCR、Nested PCR和Half-nested PCR技术从实验感染兔脾组织的总RNA中得到了覆盖猪瘟病毒(CSFV)C-株全基因组的7个cDNA重叠片段，分别克隆于pMD18—T或pGEM-T Easy载体后进行测序。运用T-A克隆和多片段一步连接法，将cDNA重叠片段F1、F2、F3、F4与F5、F6、F7分别克隆到pGEM-5Zf( )载体后，得到两个半长cDNA亚克隆重组质粒pGEM-5Zf( )／F1-4和pGEM-5Zf( )／F5-7。再将两个半长cDNA重叠片段连接并克隆到pGEM-5Zf( )载体，构建出了CSFVC-株全长cDNA重组质粒pGEM-5Zf( )／F1-7。全长cDNA的成功构建为进一步研究CSFV分子生物学提供了良好的工具。     

Molecular properties of the matrixprotein(M) gene of the lapinized rinderpest virus

The nucleotide sequence of the matrixprotein (M) gene of the lapinized rinderpest virus (RPV-L) was determined. The full-length cDNA of the RPV-L M gene is composed of 1460 base pairs and is supposed to contain an open reading frame of 1005 nucleotides encoding on M protein of 335 amino acids. The homology of the predicted amino acid among congeneric morbilliviruses such as RPV Kabete 'O' strain (wild strain of RPV), RPV RBOK strain (vaccine strain of RPV for cattle), measles virus (MV), and canine distemper virus (CDV), is approximately 94%, 93%, 87% and 77%, respectively. In the present study, all coding regions of the RPV-L strain have been determined.     

Cytology of the lower respiratory tract in horses: An updated review

The diagnosis of respiratory diseases in horses can be difficult due to the nonspecific nature of the clinical signs, which overlap between the different diseases. Cytological examination of the respiratory secretions is a helpful diagnostic tool that, when combined with clinical features and other diagnostic techniques, has the potential to improve diagnostic accuracy significantly. This review article should help readers to become familiar with the cytology of the normal respiratory tract and with the cytopathological abnormalities associated with common respiratory disorders in horses.     

半年来养猪业市场的回顾与展望

一、回顾半年来玉米价对养猪业有利,当前形势正在趋稳 饲料资源是养猪生产的基础,一年来玉米价格形势是从上涨转向稳定。近期是从高价位在回落。 1.下半年玉米价格趋势是稳中有降 6月份玉米零售价是1.10元/kg,与半年平均1.07元/kg比基本没变,只增加2.80％。由于玉米价格带动,麦麸也保持稳定,比半年平均只上涨     

Detailed analysis of an experimental challenge model for Leishmania infantum (JPC strain) in dogs

In this study, disease progression after intravenous or subdermal infection of dogs with Leishmania infantum JPC strain was monitored. A challenge performed on 14 dogs via the intravenous route with 5 x 10(7) stationary phase promastigotes of the L. infantum JPC strain was 100% successful. During a follow up period of 1.5 years, several parameters were evaluated in order to find the most reliable disease markers. Parasite detection by culture and histology were found to be very sensitive (100%). Additionally, regular physical examination, serology and serum gamma-globulin levels were found to be useful parameters in the evaluation of disease severity and are recommended for inclusion in vaccination-challenge experiments. Although this intravenous challenge model has practical limitations, the data set confirms it is the best experimental model currently available for vaccine development. Two intravenously infected dogs were treated with corticosteroids for 5 months. This treatment was shown to enhance all aspects of a Leishmania infection. Five more dogs were infected by sub-dermal injection of promastigotes mixed with a proteophosphoglycan-matrix (PSG) secreted by Leishmania that assists in transmission and infection by sand fly bite. The resulting parasite burdens were low and the animals remained asymptomatic during a 2-year follow up period. However, this procedure did result in infection in 80% of the dogs and is appealing for future development as a natural challenge model in vaccine development.     

The Haemophilus somnus disease complex (Hemophilosis): A review

Haemophilus somnus has long been associated with thrombotic meningoencephalomyelitis but has also been identified as the agent responsible for other clinical diseases including respiratory disease, reproductive problems, myocarditis, otitis, conjunctivitis, mastitis, and polyarthritis. Exposure to the bacteria is widespread and infection may occur via the respiratory tract from urogenital excretions and secretions.

Diagnosis and treatment of hemophilosis may be easy or difficult depending on the manifestation presented, and special procedures must be taken to facilitate isolation of the organism. Satisfactory control measures are not available; vaccination is the only preventive measure demonstrating a beneficial effect.

     

鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活苗(La Sota株+M41株+Re-9株)应用效果研究

鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活苗(La Sota株+M41株+Re-9株)(三联苗(Re-9株))为国内首个采用基因重组H9亚型禽流感疫苗株研制的新支流三联灭活疫苗.为研究疫苗上市后的实际应用效果,使用7日龄AA肉鸡和260日龄产蛋期蛋鸡评价三联苗(Re-9株)有效性.结果显示:肉鸡免疫后14 d...