Multiple amino acid substitutions are involved in the adaptation of H9N2 avian influenza virus to mice

To explore adaptation of avian influenza virus to mice we previously performed serial lung-to-lung passages of the influenza A/Chicken/Jiangsu/7/2002 (H9N2) strain, resulting in the isolation of a variant influenza strain lethal for mice. We now report that virulence correlates with improved growth characteristics on mammalian cells and extended tissue tropism in vivo. Sequencing of the complete genomes of the wild-type and mouse-adapted viruses revealed 25 amino acid substitutions. Some were found to reiterate known substitutions in human and swine H9N2 influenza isolates. Functions affected include nuclear localization signals and sites of protein and RNA interaction, while others are known determinants of pathogenicity and host specificity such as the viral polymerase PB2 E627K substitution. These observations suggest that enhanced growth characteristics and modified cell tropism may contribute to increased virulence in mice. We conclude that multiple amino acid substitutions are likely to be involved in the adaptation of H9N2 avian influenza virus to mice.     

鹿口蹄疫抗体间接ELISA检测方法的建立

以纯化的口蹄疫病毒作为包被抗原,建立了检测鹿口蹄疫抗体的间接酶联免疫吸附测定（ELISA）。最佳反应条件是：抗原包被质量浓度为40μg/mL,血清稀释度为1：100,检测的灵敏度为1：400。     

Analysis of risk factors associated with bovine leukemia virus seropositivity within dairy and beef breeding farms in Japan: A nationwide survey

This cross-sectional study evaluated risk factors associated with farm-level bovine leukemia virus (BLV) seropositivity in 563 dairy and 490 beef farms throughout Japan. Twenty randomly selected cattle on each farm were serologically tested, and farm epidemiologiocal information was obtained through face-to-face interviews. Due to the large number of zero-prevalence dairy and beef farms, data analysis was performed using a zero-inflated negative binomial model, which revealed that the common risk factors associated with higher within-farm seroprevalence were past detection of clinical leukemia and presence of blood-sucking insects. Loose housing on dairy farms and direct contact between calves and adult cattle on beef farms were also identified as risk factors. With regard to farm-level presence of BLV, the presence of purchased cattle was found to be a risk factor in both sectors. Sending heifers to a common ranch was identified as an additional risk factor for dairy farms.     

重庆市山羊博尔纳病病毒P24基因的检测

为了解重庆市山羊博尔纳病隐性带毒情况，分析博尔纳病病毒（BDV）的种系来源。采用巢式逆转录酶PCR结合荧光定量PCR（FQ—nRT—PCR）技术对重庆市60只山羊外周血单核细胞（PBMCs）及脑组织中的BDVP24基因片段进行了检测，将阳性产物测序，并与国外BDV毒株进行了比较。结果，山羊外周血检测阳性率为8．3％（5／60），脑组织检测阳性率为10％（6／60）。该BDVP24片段核苷酸序列与马源BDVH1766株同源性最高，达96．519／6，与标准株Strain V和He／80同源性为95．35％，并且编码的氨基酸序列也相同。表明，重庆市山羊中存在动物源性博尔纳病隐性带毒，该BDVP24核苷酸序列与Strain V和He／80株具有高度同源性。     

传染性支气管炎病毒S1基因遗传变异研究

本文利用计算机互联网分析了传染性支气管炎病毒（IBV）Buead株（呼吸型）和Z株（肾病型）S1基因的遗传变异规律。经与Genbank中50余个传染性支气管炎病毒的S1基因序列比较研究表明：Beaud株和Z株均存在着高度变异和相对保守区，两株病毒S1基因含有5－6个插入变异区。本文同时分析了两株病毒S1蛋白氨基酸序列的变异规律，研究表明：各株传染性支气管病毒之间S1蛋白的氨基酸序列有局部变异，其中105－106个氨基酸保持恒定不变。功能位点分析表明：Z株与Buead株抗原位点的位置和组成已发生变异，糖基化位点除Z株出现两个新位点外，其位置没有发生变化，但其组成已发生较多变异。     

鸡传染性支气管炎病毒S1基因免疫对鸡的保护作用

将鸡传染性支气管炎病毒肾型 Ｔ 株 Ｓ１ 基因ｃ Ｄ Ｎ Ａ 连接于ｐｃ Ｄ Ｎ Ａ３ 的 Ｈｉｎｄ Ｉ Ｉ Ｉ与 Ｂａ ｍ Ｈ Ｉ位点之间构建含有 Ｃ Ｍ Ｖ 启动子及 Ｂ Ｇ Ｈｐｏｌｙ Ａ 信号序列的鸡传染性支气管炎病毒 Ｓ１ 蛋白真核表达质粒。实验证明, Ｓ Ｐ Ｆ 鸡肌注免疫后血清 Ｉｇ Ｇ 抗体逐渐升高,至第３５ 日龄左右达到高峰,攻毒后血清 Ｉｇ Ｇ 抗体先下降而后升高,血清 Ｉｇ Ｇ 抗体升高幅度不及 Ｉ Ｂ 油苗免疫组。质粒 Ｄ Ｎ Ａ 免疫鸡攻毒后有４０ ％ 的鸡可耐过强毒的攻击,说明 Ｓ１ 基因在体内获得了表达并使鸡产生了一定的免疫力。     

中药复方治疗感染DHBV麻鸭的研究

本研究以人工感染鸭乙型肝炎病毒（ Ｄ Ｈ Ｂ Ｖ）的麻鸭为实验模型,用两组中药复方进行体内抗病毒实验研究。结果表明：１实验结束时,两个治疗组麻鸭的平均体重增长值显著高于对照组（ Ｐ＜ ０００１）,而平均肝重显著低于对照组（ Ｐ＜ ０００１）,肝系数也显著小于对照组（ Ｐ＜ ０００１）;２两个治疗组麻鸭随着服药时间的延长, Ｄ Ｈ Ｂ Ｖ 转阴率持续增加,实验结束时转阴率均分别显著高于对照组（２９２７％ 与３０５６％ ８１１％ , Ｐ＜ ００５）;而且未出现 Ｄ Ｈ Ｂ Ｖ 转阴后又转阳现象。提示这两组中药复方不仅具有抗病毒的作用,而且药物安全、药效稳定,且有较好的治疗效果;建议试用于临床治疗乙型肝炎。     

西藏兔病毒性出血症的研究--病原鉴定及疫苗免疫效力试验

１９９４年６￣７月,西藏林芝地区家兔大批急性死亡同,经过流行病学调查,临诊断症状观察,病理剖检等结果与兔病毒性出血症特征相符。进一步作病毒学检查表明,病变组织超薄发切片经电子显微镜观察发现有大量直径约３０ｎｍ的球状裸听病毒粒子,自然病死兔肝组织匀交涉 清能凝集入）型红细胞,而且血凝兔出血症病毒阳性抗血清所抑制,致病性试验结果表明,该病毒对兔有很强的致病性;用西藏自然病死兔肝组织匀浆试制的矩形疫苗兔     

鸡痘病毒282E4株Bam HI部分片段的重组载体质粒构建与序列分析

在中国鸡痘病毒２８２Ｅ４弱毒株基因组部分ＢａｍＨＩ片段的质粒ｐＵＢ、ｐＵＣ、ｐＵＤ、ｐＵＤ２、ｐＵＥ和ｐＵＦ酶切分析的基础上,对ｐＵＦ进行了亚克隆获得ｐＵＦ－Ｅ和ｐＫＳ－Ｘ,对最可能存在非必需区的ｐＵＥ质粒进行了序列分析,改造了含Ｐ１１Ｐ７．５－ＬａｃＺ报告基因盒,并在上述质粒的相应单一酶切位点插入Ｐ１１Ｐ７．５－ＬａｃＺ报告基因盒,构建成ｐＵＢ１、ｐＵＦＣ１、ｐＵＦＥ１、ｐＵＦ－Ｅ１和ｐＫＳＦ－Ｘ１５个重组载体质粒。体内重组等工作正在进行中。