江西省部分单位实验小鼠鼠痘病毒感染的调查

采用敏感性和特异性较好的酶免疫试验（ＥＩＡ）对江西省一些饲养单位在普通环境下饲养的４个品系２３２只小鼠进行了鼠痘病毒抗体检查。结果发现阳性标本３３份，阳性率为１４．２％。其中昆明小鼠的阳性率为１８．１％（３３／１８２），其它３个品系未检出。阳性感染鼠群似呈地区性分布，吉安地区未发现。     

狂犬病病毒糖蛋白转基因小鼠的构建研究

将狂犬病病毒糖蛋白ｃＤＮＡ ＢｇｌⅡ（１．６７ｋｂ）片段正向插入ｐＭＴ０１０／Ａ＾＋ＢａｍＨⅠ切点，构建重组质粒ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ，用ＥｃｏＲⅠ＋ＳａｌⅠ对ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ进行双酶切后，回收含有狂犬病病毒糖蛋白ｃＤＮＡ和绵羊ＭＴ启动子的２．７６ｋｂ片段，通过显微注射技术将该片段注入小鼠单细胞受精卵雄前核内，在进行胚胎移植后，获得４４只小鼠，经ＰＣＲ、Ｓｏｕｔｈｅｒｎ杂交及原位     

狂犬病病毒糖蛋白转基因小鼠对该病毒形成免疫耐受

对带有绵羊ＭＴ启动子－狂犬病病毒糖蛋白基因的（ＭＴ－Ｒｇｐ）的ＴｇＮ（ｏＭＴ－Ｒｇｐ）２Ｌｇｅ、ＴｇＮ（ｏＭＴ－Ｒｇｐ）４Ｌｇｅ和ＴｇＮ（ｏＭＴ－Ｒｇｐ）６Ｌｇｅ３株转基因小鼠系（子代）进行了表达检测。ＥＬＩＳＡ结果表明，小鼠肝脏、肾脏中均有糖蛋白表达产物，以肝脏的表达量较高；对肝脏的免疫组化检测结果显示，糖蛋白分布在肝脏实质细胞，主要位于细胞膜上和胞浆内。对８只ＴｇＮ（ｏＭＴ－Ｒｇｐ）２Ｌｇｅ子代鼠一次接种灭活的狂犬病病毒８２０２株，接种前和接种后３周的血清抗体水平变化在转基因鼠和非转基因鼠之间有明显区别，非转基因鼠抗狂犬病病毒抗体水平明显升高，而转基因鼠抗体水平基本保持不变。经统计学分析，转基因鼠的抗体水平变化相差不显著，表明转基因小鼠对该病毒形成了部分免疫耐受性。     

小鼠诺如病毒巢式PCR检测方法的建立及应用

为了建立一种高敏感性和特异性的检测方法,突破目前小鼠诺如病毒(MNV)检测局限,根据MNV保守区基因组序列设计合成内、外2对引物,通过PCR反应条件的优化,建立MNV的巢式PCR检测方法。结果表明,该方法仅能特异的扩增MNV目的基因而不能扩增其他病毒,且敏感度达到500个拷贝,比普通PCR提高1 000倍。说明本研究建立的巢式PCR方法具有特异性强、敏感性高、重复性好等优点,可以准确快速的用于小鼠诺如病毒的病原检测。     

小鼠诺如病毒逆转录重组酶聚合酶扩增检测方法的初步建立

小鼠是科学研究中使用最多的实验动物,小鼠诺如病毒(MNV)是试验小鼠感染率最高的病毒性病原,因此MNV感染小鼠将影响研究结果,及时对小鼠健康状态进行监测必不可少。本研究根据逆转录重组酶聚合酶扩增技术(RT-RPA),通过引物探针的筛选,建立了检测MNV的RT-RPA方法。该方法具有较好的敏感性和特异性,通过荧光扩增曲线判定样本中是否含有MNV,在20 min内即可实现样本的检测。将该方法应用于临床样本的检测,结果显示32个样本中有6个阳性,和RT-qPCR检测结果总符合率达到97%。该方法的建立对于试验小鼠的日常病原监测和MNV流行病学研究具有重要意义。     

远交群小鼠对流行性感冒病毒的敏感性比较

流行性感冒病毒A／PR8／34株（H1N1）为广泛采用的鼠肺适应株，小鼠为药物试验中的理想动物，为定期检测封闭群内小鼠的生物学特性，特进行本试验。结果表明NIH小鼠的敏感性，稳定性较佳，比较符合抗病毒药物实验的需要。     

外环境中ASFV核酸检出情况及分析

为切断非洲猪瘟病毒(African swine fever virus,ASFV)传播途径,避免其传入猪场,开展了对ASFV污染情况的调查.对湖北金林原种畜牧有限公司2020年至2021年上半年外来车辆、人员及购进物资等采集的共3778份样品进行了ASFV核酸的检测,以评估外环境中非洲猪瘟疫情的风险.结果显示,人员和物...     

小鼠病毒性肝炎模型的建立

为了建立病毒性肝炎小鼠模型,将103．875 TCID50／mL 小鼠肝炎病毒 A59（MHV-A59）经腹腔注入封闭群 NIH 小鼠体内,测定小鼠血清 ALT、AST、TP、ALB 含量等指标,并对肝脏组织病理学进行观察。结果表明,小鼠感染 MHV-A59后,约30％存活,肝脏组织呈现持续炎性改变,血清 ALT、AST 升高而 TP、ALB 有所下降。这些指标与人类病毒性肝炎的临床指标极为相似,可作为病毒性肝炎药物研究的比较理想的动物模型。     

Type A influenza viruses in waterfowl in Ohio and implications for domestic turkeys

Because ducks are considered an important reservoir for type A influenza virus, and type A influenza viruses had not been recovered from ducks in Ohio, a 3-year virus surveillance study was conducted in Ohio waterfowl and waterfowl passing through Ohio to determine if domestic turkeys were at risk of exposure to avian influenza (AI) viruses from the waterfowl reservoir. The prevalence of AI infections in ducks during the fall migration averaged about 5.9%. The 55 waterfowl-origin type A influenza viruses recovered from ducks during fall 1986, 1987, and 1988 represented 23 different hemagglutinin-neuraminidase sub-type combinations of type A influenza viruses. Virus recovery frequencies ranged from 3.6% to 7.8% between years, from 2.0% to 8.2% between study sites, from 0.0% to 16.7% for sampling days, and from 0.0% to 14.3% among species of ducks sampled.     

Development of discrimination markers between Japanese domestic and imported beef

In the meat industry, correct labeling of beef origins or breed is required to assure quality and safety. This paper describes the development of discrimination markers between Japanese domestic and imported beef from the United States (US) and Australia (AUS) based on a bovine 50K single nucleotide polymorphism (SNP) array using a total of 110 samples: Japanese Black (n = 50), Japanese Holstein (n = 50) and US cattle (n = 10). Genotyping information revealed 1081 SNPs as candidate markers that were polymorphic only in US cattle. The genotyping results by PCR – restriction length polymorphism in Japanese Black (n = 300) and Holstein cattle (n = 146) revealed that 11 SNPs had alleles specific to US cattle. Their allelic frequencies in US cattle (n = 108) ranged from 0.097 to 0.250 with an average of 0.178 and the combined identification probability of US cattle was 0.987. In addition, we also verified the applicability of these US‐specific markers to AUS cattle. Their allelic frequencies in AUS cattle (n = 280) ranged from 0.063 to 0.224 with an average of 0.137 and the combined identification probability of AUS cattle was 0.963. In conclusion, a set of these markers could be useful for discriminating between Japanese domestic and imported beef and would contribute to identify origins and prevent falsified labeling of beef.     

草鱼对进口和国产菜粕的离体消化分析

近年来,由于我国养殖业迅猛发展,饲料资源（尤其是动物性蛋白质饲料）非常缺乏。在水产饲料中,菜粕和棉粕是我国的优势蛋白饲料原料,在饲料中使用量较大,是水产饲料的主要蛋白质原料。目前,我国从加拿大和印度进口了很多油菜子,在国内加工成食用菜子油,同时也带来较多的菜粕蛋白质原料。这些进口菜粕主要消耗在各类饲料中,而水产饲料（尤其是淡水鱼饲料）消耗量大。     

Serological evidence for Japanese encephalitis and West Nile viruses in domestic animals of Nepal

A regional survey was conducted in Nepal for antibody to Japanese encephalitis virus (JEV) in domestic animals. Sera from pigs, and limited numbers of ducks and horses were collected from 16 districts in 2002-2003 and subjected to three serological tests. Of 270 porcine sera tested by C-ELISA, 55% were found positive for the presence of antibodies against Japanese encephalitis virus. Additional testing for IgM antibody to JEV revealed less than 2% of C-ELISA positive sera had evidence of recent JEV infection. Plaque reduction neutralisation tests (PRNT) using JEV, Murray Valley encephalitis (MVEV) and Kunjin (KUNV) viruses implicated JEV as the flavivirus associated with the observed antibody response in most sero-positive pigs. However, eight porcine sera with predominant neutralising antibody for KUNV (an Australasian subtype of West Nile Virus) provided evidence for the circulation of West Nile virus in Nepal.     

Antibodies to bluetongue viruses in animals imported into United States zoological gardens.

Three hundred forty-five serum samples from 30 zoological animal species which had been imported into the United States were examined retrospectively for the presence of antibody to bluetongue viruses. Ninety eight (28.4%) were positive for antibody to bluetongue group antigen by the bluetongue agar gel immunodiffusion test. Bluetongue antibodies, most of which were against serotypes exotic to the United States, were detected in 13 animal species from Africa not previously reported to be infected by bluetongue virus. The lack of virus neutralizing antibody to any of the 20 known bluetongue virus types in four of the 28 positive serums studied may indicate the existence of new bluetongue virus serotypes, cross reactions with other orbiviruses or a more rapid decline of neutralizing than precipitating antibody. The possibility of recrudescence of bluetongue virus infection from some inapparently infected zoological animals and existence of a known bluetongue vector (Culicoides variipennis) in the United States would suggest that further assessment of bluetongue in zoological animals be made.     

Detection of endophyte toxins in the imported perennial ryegrass straw

From 1997 to 1999, 29 cases of disorders were detected in cattle and horses that had been fed ryegrass straw imported from the U.S.A. These animals showed symptoms resembling ryegrass staggers and the clinical signs disappeared after removal of the straw. Endophytic hyphae were detected in the seeds of all straw samples that were responsible for the clinical cases. Lolitrem B concentrations in the straw ranged between 972 and 3740 ppb. Ergovaline concentrations were between 355 and 1300 ppb. Even though the concentrations of lolitrem B were lower than the toxic threshold proposed by Oregon State University in better part of the cases, our observations suggest the possibility that lolitrem B lower than the proposed threshold can bring disorders to sensitive individuals.     

Parasite infections in laboratory mice colonies

Problems dealing with common parasites--oxyurids, which affect laboratory mice colonies are discussed and reviewed. Their life histories, pathogenicity and immunity are examined. The attention is paid to the influence of age, sex, strain and status of the host in the infection. It is agreed that helminth infections are usually more severe in male than in female vertebrate hosts.