中东呼吸综合征

中东呼吸综合征是2012年在沙特阿拉伯发现的一种冠状病毒病。由于地理关系,目前已知该病在中东多个国家存在。根据WHO报道,该病已蔓延或输入到27个国家。该病系呼吸道及密切接触传播,最大的一起输入性后引起人传人传播的疫情发生在韩国,包括沙特在内的其他绝大多数国家为散发疫情。业已证明传染源为蝙蝠,中间宿主为单峰骆驼,迄今为止人用疫苗尚未研制成功。本综述就该病的病原学、流行病学、分子病毒学、治疗、实验室诊断等进行概述,目的 在于对该病的深入了解并加强防控。     

中东呼吸综合征冠状病毒(MERS-CoV)的研究进展

中东呼吸综合征冠状病毒(Middle East Respiratory Syndrome-Coronavirus, MERS-CoV)是继SARS冠状病毒(SARS-CoV)之后发现的一种能引起人严重急性呼吸道疾病且具有高致死率的新型病毒。目前还没有有效的抗病毒治疗药物或疫苗。现已从主要流行的中东地区逐渐蔓延至多个国家,具有全球流行的潜在趋势,引起了世界各国的极大关注及众多的调查研究。本文主要对MERS-CoV的传播源及途径、致病机理和抗病毒药物及疫苗等的研究进展做一综述,以期对研制特异的抗病毒药物及疫苗和实施切实有效的预防及控制措施提供参考。     

严重急性呼吸综合征重症病例的治疗

自 2 0 0 2年 1 1月我国广东省发生首例严重急性呼吸综合征 (SARS)病例后 ,至今已经历了半年时间 ,《中华传染病杂志》已发表了多篇有关此病的综述与回顾性分析 ,这些资料甚为可贵 ,对我们的防治工作起到了重要的指导意义。现就目前在重症病例救治中遇到的几个问题谈谈看法。一、综合治疗1 .糖皮质激素应用的指征　重症SARS病例进入过度免疫应答阶段 ,肺巨噬细胞增多 ,炎性细胞因子生成过多 ,引起肺部弥漫性肺泡损害 ,影响气体交换。糖皮质激素能减少肺部渗出 ,促进炎症吸收 ,并减轻中毒症状 ,但糖皮质激素的应用是有指征的 ,具体应定位…     

严重急性呼吸综合征病毒溯源研究进展

严重急性呼吸综合征 (SARS)是由新的冠状病毒引起的 ,现已基本得到控制 ,但该病毒的来源却一直困扰着科学家。直到 2 0 0 3年 5月 2 3日中国深圳和香港的科学家[1] 通过基因分析证实动物SARS样病毒是人SARS冠状病毒(SARS CoV)的前体 ,有关SARS CoV溯源研究才取得实质性进展。SARS CoV源的推测SARS恢复期患者血清中能检测到抗 SARS CoV ,但在SARS暴发以前的人血清标本库中却检测不到这种抗体[2 ] 。这说明对人类来说 ,SARS CoV是一种新型病毒。可以推测 ,此新型病毒可能是获得了新毒力因子的人冠状病毒变异株 ,或是能感…     

阿德福韦酯诱发范可尼综合征和骨软化症病例报告和误诊分析

1病例报告患者,男,59岁。患慢性乙型肝炎10年,因HBVDNA>107copies/ml、转氨酶轻度异常及脾脏增大,于4年前开始服用阿德福韦酯(ADV)10mg/d进行抗病毒治疗,12周后转氨酶恢复正常,24周后     

严重急性呼吸综合征研究进展

严重急性呼吸综合征（severe acute respiratory syndmme，SARS）的病原体是一种以前未知的冠状病毒，命名为SARS冠状病毒（SARS-CoV）。目前，我国已将其列人乙类传染病。现就SARS的有关研究进展综述如下。     

中东呼吸综合征疫苗研究进展

中东呼吸综合征是由中东呼吸综合征冠状病毒引起的一种具有传染性和高致死性的呼吸系统疾病,该病自2012年首次确诊以来,在全球范围内广泛传播,对全球公共卫生安全构成严重威胁,目前还没有批准的预防或治疗制剂。这篇综述讨论了与MERS-CoV疫苗开发相关的病毒特性、动物模型,以及目前正在开发的候选疫苗,包括DNA疫苗、亚单位疫苗、病毒载体疫苗、灭活疫苗和减毒活疫苗等,以期为研制安全、高效的中东呼吸综合征疫苗提供参考。     

中东呼吸综合征冠状病毒量子点免疫层析试纸的制备北大核心CSCD

目的制备一种能快速检测中东呼吸综合征冠状病毒(MERS-CoV)的量子点免疫层析试纸,以期用于MERSCoV感染检测。方法采用EDC偶联法将羧基化CdTe/ZnSe量子点与抗MERS-CoV RBD的单克隆抗体(mAb/MERS-CoV)共价偶联,通过斑点免疫印迹检验偶联物的活性。以CdTe/ZnSe量子点标记的mAb/MERS-CoV作为荧光标记物,采用免疫层析技术制备量子点免疫层析试纸,用于MERS-CoV检测。并对该方法进行特异性、敏感性评价。结果 CdTe/ZnSe量子点可偶联mAb/MERS-CoV,且偶联物具有良好的生物活性。以其作为荧光标记物建立的量子点免疫层析试纸可特异性检测MERS-CoV假病毒,最低检测限为2×53 TCID50/ml,其他对照病毒检测均阴性。结论制备的MERS-CoV量子点免疫层析试纸具有简便、快速、特异等优点,可用于MERS-CoV感染快速诊断和流行病学调查。     

人ω干扰素克隆、表达及体外抑制冠状病毒昆徐株作用的研究

目的 制备人ω干扰素(hIFN-ω)并初步研究其体外抗普通冠状病毒活性.方法 制备hIFN-ω cDNA,并在大肠杆菌BL-21中高效表达、纯化后,测定了hIFN一ω的抗滤泡口膜炎病毒(VSV)和冠状病毒昆徐株活性.结果 成功地获得了hIFN-ω GST融合蛋白,利用WISH-VSV系统检测hIFN-ω的抗病毒活力为7.81×104 kU/L;与基因工程α干扰素(IFN-a2b)的比较发现,hIFN-ω可以明显抑制冠状病毒昆徐株的活性,而IFN-α2b未见此活性.结论 hIFN-ω具有抑制冠状病毒昆徐株的活性,有独特的抗呼吸道病毒作用;不同的干扰素亚型对不同的病毒敏感性有所差异.     

中东呼吸综合征冠状病毒实时荧光定量PCR检测方法的建立

目的建立一种快速、敏感、特异的实时荧光定量PCR(Real-time PCR)方法,用于中东呼吸综合征冠状病毒(MERS-CoV)的检测。方法根据中东呼吸综合征冠状病毒S蛋白基因的保守序列设计并合成一对引物及一条特异性TaqMan探针。通过条件优化,以10倍系列稀释重组质粒为标准品,进行Real-time PCR扩增,绘制标准曲线,并进行重复性、准确性、特异性及敏感性检测。结果建立的Real-time PCR方法检测中东呼吸综合征冠状病毒所绘制标准曲线的相关系数0.99,灵敏度为1.00×101拷贝,高于常规PCR方法(1.00×102拷贝);用该方法检测中东呼吸综合征冠状病毒基因为阳性,其他6种对照呼吸道病原体及冠状病毒基因检测均呈阴性;批内、批间重复试验的变异系数均1%。结论建立的中东呼吸综合征冠状病毒Real-time PCR检测方法灵敏、特异、重复性好,可用于中东呼吸综合征冠状病毒感染的快速诊断和流行病学调查。     

Host cell entry of Middle East respiratory syndrome coronavirus after two-step,furin-mediated activation of the spike protein

Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly identified betacoronavirus causing high morbidity and mortality in humans. The coronavirus spike (S) protein is the main determinant of viral entry, and although it was previously shown that MERS-CoV S can be activated by various proteases, the details of the mechanisms of proteolytic activation of fusion are still incompletely characterized. Here, we have uncovered distinctive characteristics of MERS-CoV S. We identify, by bioinformatics and peptide cleavage assays, two cleavage sites for furin, a ubiquitously expressed protease, which are located at the S1/S2 interface and at the S2′ position of the S protein. We show that although the S1/S2 site is proteolytically processed by furin during protein biosynthesis, the S2′ site is cleaved upon viral entry. MERS-CoV pseudovirion infection was shown to be enhanced by elevated levels of furin expression, and entry could be decreased by furin siRNA silencing. Enhanced furin activity appeared to partially override the low pH-dependent nature of MERS-CoV entry. Inhibition of furin activity was shown to decrease MERS-CoV S-mediated entry, as well as infection by the virus. Overall, we show that MERS-CoV has evolved an unusual two-step furin activation for fusion, suggestive of a role during the process of emergence into the human population. The ability of MERS-CoV to use furin in this manner, along with other proteases, may explain the polytropic nature of the virus.Coronaviruses have recently generated substantial interest from the biomedical community based on the emergence and isolation of a deadly coronavirus infecting humans (1), Middle East respiratory syndrome coronavirus (MERS-CoV). To date, there have been 837 cases of MERS, with a mortality rate of 35% and confirmed spread within the Middle East and imported cases in Europe, North Africa, Asia, and North America. The disease is manifested by severe respiratory infection, often with additional clinical signs including renal failure. Such clinical signs are similar to those involved in severe acute respiratory syndrome (SARS) infection; however, MERS-CoV is more closely related to viruses in betacoronavirus lineage C (2), whereas SARS-CoV is classified as a lineage B betacoronavirus. Although bats are thought to be the ultimate reservoir of the precursor to MERS-CoV, there is mounting evidence that camels can be infected with MERS-CoV, indicating a possible role in spread or transmission (3). MERS-CoV infections show some features of SARS, but with only limited evidence for human–human transmission to date. Despite clinical similarities between MERS and SARS, MERS-CoV is distinct from SARS-CoV in several biological aspects: it uses a distinct receptor (DPP4) (4) and is classed as a “generalist” coronavirus, in that it is able to infect a broad range of cells in culture (5, 6). Such a polytropic coronavirus is unusual and is alarming from an epidemiological standpoint (7).Enveloped viruses, similar to coronaviruses, access host cells by membrane fusion, mediated by a specific fusion protein that is often primed for fusion activation by proteolytic cleavage (8). An important concept, typified by highly pathogenic avian influenza virus, is that modulation of the priming event can have profound implications for viral tropism and pathogenesis (9). As such, an understanding of envelope protein cleavage is fundamental to an overall understanding of viral pathogenesis. The proteases that activate virus envelope proteins recognize specific amino acids within the residue designation P6-P6′, where P1 indicates the cleavage position. In the case of highly pathogenic avian influenza virus hemagglutinin (HA), it is mutations in the cleavage site by the addition of basic residues in the P6–P2 positions (the polybasic region), switching the proteolytic enzyme processing HA from trypsin-like to furin-like proteases, that allow for marked changes in pathogenesis.The coronavirus spike (S) is unusual in that a range of different proteases can cleave and activate it (10). As such, coronaviruses may be considered to be viruses that can adapt well to new environments based on protease availability, along with the more conventional receptor-binding aspects of viral tropism. Another key feature of coronavirus S is that the proteolytic cleavage events that lead to membrane fusion can occur both at the interface of the receptor binding (S1) and fusion (S2) domains (S1/S2), as well as in a novel position adjacent to a fusion peptide within S2 (S2′) (11, 12).The only other well-characterized coronavirus that has the polytropic features associated with MERS-CoV is infectious bronchitis virus (IBV) Beaudette strain. IBV-Beaudette has been highly chicken embryo- and cell culture-adapted, and unlike field strains of IBV (which are highly restricted to primary chicken cells), it infects a wide variety of cell lines in culture (13). A notable feature of IBV-Beaudette S is the presence of a critical furin cleavage site at the S2′ site, as well as at S1/S2 (11, 12); this makes it distinct from all other IBVs, which only contain a furin cleavage site at S1/S2. Expanded tropism of IBV-Beaudette strongly correlates with furin expression levels in cells (13).MERS-CoV studies have shown that S can be cleaved during protein biosynthesis, and it has been demonstrated that the virus can use an endosomal pathway to enter cells via activation by cathepsins (14-16). MERS-CoV is also able to enter cells using an alternative pathway at the cell surface with activation by transmembrane protease, serine 2 (TMPRSS2), and TMPRSS4.Although a picture is emerging in which MERS-CoV appears to be able to use different entry pathways, precise information on the location, timing, and nature of the proteolytic activation mechanisms involved is still lacking. Here we analyze the cleavage sites of MERS-CoV S and identify two functional furin cleavage sites at the S1/S2 and S2′ sites, a highly unusual feature we believe has important consequences for virus entry, tropism, and emergence in the human population.