SARS相关新型冠状病毒研究

20 0 2年末 ,中国广东省报告出现有不明原因且危及生命的严重呼吸道疾病 ,紧接着 ,在越南、加拿大、香港也报告有严重发热性呼吸系统疾病 ,主要传播至家庭成员及卫生工作者。该综合征在 2 0 0 3年 2月后期被命名为急性重症呼吸系综合征 (Se vereacuterespiratorysyndrome ,SARS) ,2 0 0 3年 3月制定了全球动员令以了解病因并控制传播。越南、新加坡、泰国、香港、加拿大、台湾和美国各国和地区一起合作 ,将符合SARS病例诊断标准的病例临床标本送往美国CDC ,作为病因学调查的一部分。本文描述了美国CDC为确认大范围潜在可能病原体所做…     

SARS病毒、冠状病毒与肉品检验

2003年10月6日,世界卫生组织(WHO)提醒各国必须警惕11月非典型肺炎卷土重来。世界卫生组织说,非典可能通过人们与感染病毒的野生动物接触而再次传播,科学家们已经确定了SARS为变异的冠状病毒,那么动物性食品中SARS病毒及冠状病毒的检验就有了非同寻常的意义。     

SARS冠状病毒基因溯源分子生物信息学分析

目的：对广东省两次流行的SARS冠状病毒（SARS—CoV）进行分子水平的溯源分析，为进一步研究SARS冠状病毒提供分子生物信息学资料。方法：对GenBank登录的SARS冠状病毒和SARS样冠状病毒（SARS—like CoV）核酸序列进行了分析，以Breda病毒为外组，构建了SARS冠状病毒和SARS样冠状病毒系统进化树，并进行单核苷酸变异分析。结果：发现两次SARS自然流行的病毒可分为两个明显不同的聚类；第二次流行时从人类中分离的SARS冠状病毒和从果子狸等动物中分离的SARS样冠状病毒可分为两个基因型，两型的主要鉴别依据是病毒的全基因组变异而非Spike基因序列。结论：前后两次SARS自然流行病毒可能以不同的特性感染人类而不是简单的重复。结合流行病学资料，对第二次流行时的SARS冠状病毒进行分子水平溯源分析的结果表明，分离自前2例指标患者的病毒基因序列与来自果子狸等动物的SARS样冠状病毒的基因序列存在较大的差异。提示第二次流行的SARS冠状病毒由果子狸等动物传染人的论据不足。     

SARS病毒和其他冠状病毒中性突变速率初步的比较研究

目的比较SARS冠状病毒(SARS-CoV)与第1至第3组(其他3组)冠状病毒的中性突变速率之异同,为更深入研究SARS-CoV起源提供新的思路。方法在美国国立生物技术信息中心中获取其他3组26条病毒序列,同时选取7条SARS-CoV序列。计算各病毒株5个主要基因串联序列的同义替换核苷酸的数量(Ks值),以此值与时间创建散点图,并进行直线拟合,取得各自中性突变速率并比较。结果 SARS-CoV中性突变速率为7.33×10-6/位点.天,而其他3组冠状病毒为2×10-6/位点.天,仅约前者的1/3.5,但决定系数R2极低,无意义。经多种拟合检验,发现标本量和离散性不是本文R2低值的主要原因。结论用同一方法对SARS-CoV和其他3组冠状病毒的中性突变速率进行比较研究,结果显示两者明显不同或具不同的模式;提示和其他3组冠状病毒相比较,SARS-CoV在分子进化或起源模式上似有特别之处。     

中国科学家发现新型SARS样冠状病毒

军事医学科学院军事兽医研究所的研究员涂长春领衔的联合课题组，在云南蝙蝠体内检测出了新型SARS样冠状病毒，全基因组序列测定与抗原性分析表明该病毒具备感染人的能力，推断其很可能是SARS病毒的祖先或“亲属”，为理清SARS来源提供了重要数据。国际核心学术期刊《病毒学杂志》近日在线发表了这一最新研究成果。     

追查元凶冠状病毒

自非典型性肺炎不断扩散，各方专家都竭力追寻病毒的源头。最初中国大陆的学者提出是副粘液病毒引发了致使疫症，接着香港的专家具体怀疑到间质肺病毒或呼吸道融合瘤病毒头上，3月中旬，香港大学微生物学系主任袁国勇在全球最早指出冠状病毒是致命主因。     

介绍一种SARS病毒消毒头罩的制作与应用

设制一种应用于运送患者途中的隔离防护消毒头罩，经省厅领导及专家鉴定，肯定了效果。现介绍如下。     

上海地区SARS患者冠状病毒样颗粒培养与分离

目的 对上海地区SARS患进行病原体的培养10分离。方法 复旦大学公共卫生学院与上海市疾病预防控制中心合作,对上海地区第1例、第2例SARS确诊病例咽拭标本接种多种细胞,进行病原分离、观察。结果 在第1例SARS确诊病例咽拭标本感染的Vero E6细胞观察到CPE;经超速离心、电镜负染观察见到了直径在60～100nm的冠状病毒样颗粒;感染的VeroE6细胞和病人血清间接荧光抗体显示阳性。此株冠状病毒样颗粒暂时命名为SARS—CoV—Fudan I株。结论 在上海市的第1例确诊SARS病例的咽试培养中,见到新型冠状病毒样的颗粒。     

初筛核酸阴性的新型冠状病毒肺炎1例

Detection of nucleic acid is a method to first confirm COVID-19 theoretically, but it may show false negative result in clinical practice. This study indicates that suspected patients with COVID-19 cannot be ruled out easily because of once or twice negative results of nucleic acid detection. The epidemiology and radiological findings should be closely monitored. Dynamic test for viral nucleic acid is needed to avoid missed diagnosis, thus causing the spread of disease and missing the best time for early treatment. Clinical epidemiology, radiological findings, sampling time and criteria have posed significance to diagnose the disease and judge the severity.     

初筛阴性的新型冠状病毒肺炎患者1例

病毒核酸检测对于新型冠状病毒肺炎的诊断具有重要意义,而在临床中也出现了核酸检测初筛阴性且最终确诊的患者。在治疗中,新型冠状病毒肺炎患者有临床症状与肺部实际病变程度相分离的特点。一些患者临床症状并不重,但影像学检查却显示病变明显。本例病例提示对于新型冠状病毒肺炎疑似患者,病毒核酸阴性,不能简单排除。应密切追踪患者影像学表现,并及时进行病毒核酸复检,以免漏诊,造成病毒传播,错过治疗时机。在临床治疗中影像学检查对于新型冠状病毒肺炎患者病变程度判断、指导治疗同样具有重要意义。     

A novel subunit ISCOM vaccine against bovine virus diarrhoea virus.

The preparation and preliminary testing of a subunit ISCOM (immunostimulating complex) vaccine against bovine virus diarrhoea virus (BVDV) is described. Vaccination of calves with this vaccine yields high neutralising titres against a panel of Danish BVDV field isolates. The serological difference between virus isolates and vaccine strain selection is discussed.     

A novel linear neutralizing epitope of hepatitis E virus

Hepatitis E virus (HEV) is a serious public health problem that causes acute hepatitis in humans and is primarily transmitted through fecal and oral routes. The major anti-HEV antibody responses are against conformational epitopes located in a.a. 459–606 of HEV pORF2. All reported neutralization epitopes are present on the dimer domain constructed by this peptide. While looking for a neutralizing monoclonal antibody (MAb)-recognized linear epitope, we found a novel neutralizing linear epitope (L2) located in a.a. 423–437 of pORF2. Moreover, epitope L2 is proved non-immunodominant in the HEV-infection process. Using the hepatitis B virus core protein (HBc) as a carrier to display this novel linear epitope, we show herein that this epitope could induce a neutralizing antibody response against HEV in mice and could protect rhesus monkeys from HEV infection. Collectively, our results showed a novel non-immunodominant linear neutralizing epitope of hepatitis E virus, which provided additional insight of HEV vaccine.     

甲型H1N1流感流行病学研究进展

甲型H1N1流感的预防控制经历了外堵策略(containment strategy),已经转入内防阶段(mitigation phase).新的甲型H1N1流感病毒毒株引发的流感大流行还在全球蔓延,防控工作充满着新的挑战.本文对甲型H1N1流感流行病学相关文献进行综述,旨在为我国各地对该病的预防控制提供帮助.     

A novel assay for influenza virus quantification using surface plasmon resonance

Quantification of hemagglutinin (HA) by single-radial immuno diffusion (SRID) is the predominant method to ensure product potency in seasonal influenza vaccines. Here a new method for quantification of influenza virus using biosensor technology is presented. The method employs quantification of virus via an inhibition assay format using HA proteins for H1N1, H3N2 and B immobilized on a sensor chip. Initial results showed the assay to have higher sensitivity (detection range 0.5–10 μg/ml), higher precision and significantly lower analysis and hands on time compared with SRID.     

Systematic phylogenetic analysis of influenza A virus reveals many novel mosaic genome segments

Recombination plays an important role in shaping the genetic diversity of a number of DNA and RNA viruses. Although some recent studies have reported bioinformatic evidence of mosaic sequences in a variety of influenza A viruses, it remains controversial as to whether these represent bona fide natural recombination events or laboratory artifacts. Importantly, mosaic genome structures can create significant topological incongruence during phylogenetic analyses, which can mislead additional phylogeny-based molecular evolutionary analyses such as molecular clock dating, the detection of selection pressures and phylogeographic inference. As a result, there is a strong need for systematic screenings for mosaic structures within the influenza virus genome database. We used a combination of sequence-based and phylogeny-based methods to identify 388 mosaic influenza genomic segments, of which 332 are previously unreported and are significantly supported by phylogenetic methods. It is impossible, however, to ascertain whether these represent natural recombinants. To facilitate the future identification of recombinants, reference sets of non-recombinant sequences were selected for use in an automatic screening protocol for detecting mosaic sequences. Tests using real and simulated mosaic sequences indicate that our screening protocol is both sensitive (average >90%) and accurate (average >77%) enough to identify a range of different mosaic patterns. The relatively high prevalence of mosaic influenza virus sequences implies that efficient systematic screens, such as that proposed here, should be performed routinely to detect natural recombinant strains, potential laboratory artifacts, and sequencing contaminants either prior to sequences being deposited in GenBank or before they are used for phylogenetic analyses.     

A novel tetrameric gp350 as a potential Epstein–Barr virus vaccine

Infectious mononucleosis and B-cell transformation in response to infection with Epstein–Barr virus (EBV) is dependent upon binding of the EBV envelope glycoprotein gp350 to CD21 on B-cells. Gp350-specific antibody comprises most of the EBV neutralizing activity in the serum of infected patients, making this protein a promising target antigen for a prophylactic EBV vaccine. We describe a novel, tetrameric gp350-based vaccine that exhibits markedly enhanced immunogenicity relative to its monomeric counterpart. Plasmid DNA was constructed for synthesis, within transfected CHO cells, of a tetrameric, truncated (a.a. 1–470) gp350 protein (gp350^1–470). Tetrameric gp350^1–470 induced ∼20-fold higher serum titers of gp350^1–470-specific IgG and >19-fold enhancements in neutralizing titers at the highest dose, and was >25-fold more immunogenic on a per-weight basis than monomeric gp350^1–470. Further, epidermal immunization with plasmid DNA encoding gp350^1–470 tetramer induced 8-fold higher serum titers of gp350^1–470-specific IgG relative to monomer. Tetrameric gp350^1–470 binding to human CD21 was >24-fold more efficient on a per-weight basis than monomer, but neither tetramer nor monomer mediated polyclonal human B-cell activation. Finally, the introduction of strong, universal tetanus toxoid (TT)-specific CD4+ T-cell epitopes into the tetrameric gp350^1–470 had no effect on the gp350^1–470-specific IgG response in naïve mice, and resulted in suppressed gp350^1–470-specific IgG responses in TT-primed mice. Collectively, these data suggest that tetrameric gp350^1–470 is a potentially promising candidate for testing as a prophylactic EBV vaccine, and that protein multimerization, using the approach described herein, is likely to be clinically relevant for enhancing the immunogenicity of other proteins of vaccine interest.     

A novel broad-spectrum treatment for respiratory virus infections: influenza-based defective interfering virus provides protection against pneumovirus infection in vivo

Respiratory viruses represent a major clinical burden. Few vaccines and antivirals are available, and the rapid appearance of resistant viruses is a cause for concern. We have developed a novel approach which exploits defective viruses (defective interfering (DI) or protecting viruses). These are naturally occurring deletion mutants which are replication-deficient and multiply only when coinfection with a genetically compatible infectious virus provides missing function(s) in trans. Interference/protection is believed to result primarily from genome competition and is therefore usually confined to the virus from which the DI genome originated. Using intranasally administered protecting influenza A virus we have successfully protected mice from lethal in vivo infection with influenza A viruses from several different subtypes [1]. Here we report, contrary to expectation, that protecting influenza A virus also protects in vivo against a genetically unrelated respiratory virus, pneumonia virus of mice, a pneumovirus from the family Paramyxoviridae. A single dose that contains 1 μg of protecting virus protected against lethal infection. This protection is achieved by stimulating type I interferon and possibly other elements of innate immunity. Protecting virus thus has the potential to protect against all interferon-sensitive respiratory viruses and all influenza A viruses.     

A novel dengue virus serotype-2 nanovaccine induces robust humoral and cell-mediated immunity in mice

Dengue virus (DENV), a member of the Flaviviridae family, can be transmitted to humans through the bite of infected Aedes mosquitoes. The incidence of dengue has increased worldwide over the past few decades. Inadequate vector control, changing global ecology, increased urbanization, and faster global travel are factors enhancing the rapid spread of the virus and its vector. In the absence of specific antiviral treatments, the search for a safe and effective vaccine grows more imperative. Many strategies have been utilized to develop dengue vaccines. Here, we demonstrate the immunogenic properties of a novel dengue nanovaccine (DNV), composed of ultraviolet radiation (UV)-inactivated DENV-2, which has been loaded into the nanoparticles containing chitosan/Mycobacterium bovis Bacillus Calmette-Guerin cell wall components (CS/BCG-NPs). We investigated the immunogenicity of DNV in a Swiss albino mouse model. Inoculation with various concentrations of vaccine (0.3, 1, 3 and 10 μg/dose) with three doses, 15-day apart, induced strong anti-dengue IgM and IgG antibodies in the mouse serum along with neutralizing antibody against DENV-2 reference strain (16681), a clinical-isolate strain (00745/10) and the mouse-adapted New Guinea-C (NGC) strain. Cytokine and chemokine secretion in the serum of DNV-immunized mice showed elevated levels of IFN-γ, IL-2, IL-5, IL-12p40, IL-12p70, IL-17, eotaxin and RANTES, all of which have varying immune functions. Furthermore, we observed a DNV dose-dependent increase in the frequencies of IFN-γ-producing CD4⁺ and CD8⁺ T cells after in vitro stimulation of nucleated cells. Based on these findings, DNV has the potential to become a candidate dengue vaccine.     

基于全基因组序列对新型H7N9禽流感病毒进化率评估

目的基于新型H7N9禽流感病毒的全基因组序列,估算该病毒8个基因结构区及整体的进化率,为进一步探索H7N9的进化机制提供理论支持。方法选取全球共享禽流感数据倡议组织(GISAID)中以人类为宿主的H7N9病毒基因序列,同时合并与新型H7N9的6个内部基因结构区具有高度同源性的H9N2序列;采用Bio Edit7.0软件进行多序列比对,MEGA 6.06建立系统发育树;利用Path-o-gen软件初步估算进化率,并以此作为先验信息,基于分子时钟和蒙特卡罗马尔科夫链(MCMC)模型进一步估算H7N9各基因结构区的进化率。结果进化率结果表明H7N9禽流感病毒进化快,全基因进化率为4.60×10^–3次/位点/年(95%CI=3.94×10^–3~5.40×10^–3),血凝素(HA)和神经氨酸酶(NA)具有较快的进化率,分别为7.43×10^–3和5.92×10^–3次/位点/年,聚合酶A(PA)、聚合酶B1(PB1)和聚合酶B2(PB2)进化速度也相对较其他基因片段快。结论 H7N9病毒进化速度快,急需建立一个有效长期的流感病毒监测制度。