Molecular detection of SARS-CoV-2 being challenged by virus variation and asymptomatic infection

Coronavirus disease 2019 (COVID-19) has been a pandemic for more than a year. With the expanding second wave of the pandemic in winter, the continuous evolution of SARS-CoV-2 has brought new issues, including the significance of virus mutations in infection and the detection of asymptomatic infection. In this review, we first introduced several major SARS-CoV-2 mutations since the COVID-19 outbreak and then mentioned the widely used molecular detection techniques to diagnose COVID-19, primarily focusing on their strengths and limitations. We further discussed the effects of viral genetic variation and asymptomatic infection on the molecular detection of SARS-CoV-2 infection. The review finally summarized useful insights into the molecular diagnosis of COVID-19 under the special situation being challenged by virus mutation and asymptomatic infection.     

全球自然感染SARS-CoV-2人群的抗体水平研究

新型冠状病毒肺炎（COVID-19）已蔓延至全球二百二十多个国家和地区,造成了全球大流行。通过SARS-CoV-2的特异性抗体的血清学检测可以估计人群感染的状况,有助于回顾性评估研究人群中疫情的规模或感染程度。本文对全球自然感染SARS-CoV-2一般人群和医务工作者、儿童、孕妇等特殊人群的血清抗体水平研究进行综述,以期更好地理解COVID-19流行期间人群的血清学特征和规律,对疾病的认识和后期疫情防控提供重要借鉴。综述发现全球范围内报告的自然感染SARS-CoV-2血清抗体阳性率在不同国家或地区有所不同,阳性率从低于0.1%到超过20%,其高低与不同血清学检测方法、检测时所处的疫情流行阶段有关。儿童的血清抗体阳性率低于其他年龄组,医务工作者、孕妇的血清抗体阳性率则与一般人群相似。未来有必要进一步持续监测血清抗体阳性水平,以评估COVID-19所致的疾病负担,为COVID-19疫情控制提供科学证据。     

Angiotensin-converting enzyme 2 as a potential therapeutic target for COVID-19: A review

As of August 16, 2021, there have been 207,173,086 confirmed cases and 4,361,996 deaths due to the coronavirus disease (COVID-19), and the pandemic remains a global challenge. To date, no effective and approved drugs are available for the treatment of COVID-19. Angiotensin-converting enzyme 2 (ACE2) plays a crucial role in the invasion into host cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19. Notably, ACE2 density is influenced by medical conditions, such as hypertension, or by drugs, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which can change the fate of SARS-CoV-2 infectivity. ACE2 is a target for these drugs and can be manipulated to limit the viral entry and replication within the cells. Different strategies aimed at blocking ACE2 with small molecules, peptides, and antibodies, or by neutralizing the virus through its competitive binding with human recombinant soluble ACE2 (hrsACE2) are currently under investigation. In this article, we review the current state of knowledge that emphasizes the need to find effective therapeutic agents against COVID-19 by exploiting ACE2 as a potential target. The increased soluble ACE2 levels and the application of hrsACE2 in patients with COVID-19 can be implemented to control the disease. It has not yet been established whether hypertension and other comorbidities, independent of age, have a direct role in COVID-19. Therefore, the use of renin-angiotensin system inhibitors, ACEIs and ARBs, should not be discontinued during COVID-19 treatment.     

Molecular immune pathogenesis and diagnosis of COVID-19

Coronavirus disease 2019(COVID-19)is a kind of viral pneumonia which is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).The emergence of SARS-CoV-2 has been marked as the third introduction of a highly pathogenic coronavirus into the human population after the severe acute respiratory syndrome coronavirus(SARS-CoV)and the Middle East respiratory syndrome coro-navirus(MERS-CoV)in the twenty-first century.In this minireview,we provide a brief introduction of the general features of SARS-CoV-2 and discuss current knowledge of molecular immune pathogenesis,diagnosis and treatment of COVID-19 on the base of the present understanding of SARS-CoV and MERS-CoV infections,which may be helpful in offering novel insights and potential therapeutic targets for combating the SARS-CoV-2 infection.     

Structural elucidation of SARS-CoV-2 vital proteins: Computational methods reveal potential drug candidates against main protease,Nsp12 polymerase and Nsp13 helicase

Recently emerged SARS-CoV-2 caused a major outbreak of coronavirus disease 2019 (COVID-19) and instigated a widespread fear, threatening global health safety. To date, no licensed antiviral drugs or vaccines are available against COVID-19 although several clinical trials are under way to test possible therapies. During this urgent situation, computational drug discovery methods provide an alternative to tiresome high-throughput screening, particularly in the hit-to-lead-optimization stage. Identification of small molecules that specifically target viral replication apparatus has indicated the highest potential towards antiviral drug discovery. In this work, we present potential compounds that specifically target SARS-CoV-2 vital proteins, including the main protease, Nsp12 RNA polymerase and Nsp13 helicase. An integrative virtual screening and molecular dynamics simulations approach has facilitated the identification of potential binding modes and favourable molecular interaction profile of corresponding compounds. Moreover, the identification of structurally important binding site residues in conserved motifs located inside the active site highlights relative importance of ligand binding based on residual energy decomposition analysis. Although the current study lacks experimental validation, the structural information obtained from this computational study has paved way for the design of targeted inhibitors to combat COVID-19 outbreak.     

Reducing SARS-CoV-2 pathological protein activity with small molecules

Coronaviruses are dangerous human and animal pathogens. The newly identified coronavirus SARS-CoV-2 is the causative agent of COVID-19 outbreak, which is a real threat to human health and life. The world has been struggling with this epidemic for about a year, yet there are still no targeted drugs and effective treatments are very limited. Due to the long process of developing new drugs, reposition of existing ones is one of the best ways to deal with an epidemic of emergency infectious diseases. Among the existing drugs, there are candidates potentially able to inhibit the SARS-CoV-2 replication, and thus inhibit the infection of the virus. Some therapeutics target several proteins, and many diseases share molecular paths. In such cases, the use of existing pharmaceuticals for more than one purpose can reduce the time needed to design new drugs. The aim of this review was to analyze the key targets of viral infection and potential drugs acting on them, as well as to discuss various strategies and therapeutic approaches, including the possible use of natural products. We highlighted the approach based on increasing the involvement of human deaminases, particularly APOBEC deaminases in editing of SARS-CoV-2 RNA. This can reduce the cytosine content in the viral genome, leading to the loss of its integrity. We also indicated the nucleic acid technologies as potential approaches for COVID-19 treatment. Among numerous promising natural products, we pointed out curcumin and cannabidiol as good candidates for being anti-SARS-CoV-2 agents.     

严重急性呼吸综合征冠状病毒2与新型冠状病毒肺炎

目前正在暴发流行的新型冠状病毒肺炎（COVID-19）的病原体是严重急性呼吸综合征冠状病毒2（SARS-CoV-2）,这是近年来继严重急性呼吸综合征冠状病毒（SARS-CoV）和中东呼吸综合征冠状病毒（MERSCoV）之后发现的能够感染人的第7种冠状病毒。SARS-CoV-2系单股正链RNA病毒,传染性强,人群普遍对其缺乏免疫力,疫情目前仍在持续。2020年1月30日（当地时间）,WHO将此次疫情列为国际关注的突发公共卫生事件（PHEIC）。本文就SARS-CoV-2病原学、致病性及COVID-19的检测诊断、预防控制和临床治疗等领域的进展进行讨论。     

从一对夫妻患者的诊治过程探讨2019冠状病毒病(COVID-19)疑似患者的管理

观察2例2019冠状病毒病（COVID-19）疑似患者诊断、治疗以及隔离管理的过程,结合文献分析COVID-19疑似患者的临床特征和管理重点。COVID-19是由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染所致的疾病,SARS-CoV-2具有很强的传染性,甚至无症状感染者也可能传播病毒。SARS-CoV-2可通过接触传播、飞沫传播,并可能通过气溶胶传播。在临床发热门诊的患者管理中,准确识别并管理好疑似患者,采取严格的隔离措施,对院内感染的防控极为重要。     

SARS-CoV-2对神经系统损害的研究进展

由严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)所引起 的2019 冠状病毒病(coronavirus disease 2019,COVID-19)疫情在全球大暴发。SARS-CoV-2 感染除了可累及呼吸系统 外,还可导致严重的神经系统损伤。研究表明SARS-CoV-2 可通过血行和跨神经元途径入侵神经系统,并可能通过抑 制细胞免疫、低氧血症及炎症作用,诱导神经元变性与细胞凋亡,以及血管紧张素转化酶2(angiotensin converting enzyme 2,ACE2)机制造成COVID-19 患者的神经系统损害,导致患者颅内感染、中毒性脑病、急性脑血管疾病、肌 肉损害、周围神经系统损伤、急性脊髓炎、脱髓鞘疾病或其他神经系统疾病。     

上海2株严重急性呼吸综合征冠状病毒2的分离与鉴定

目的 从新型冠状病毒肺炎（COVID-19）患者鼻/咽拭子样本中分离、培养严重急性呼吸综合征冠状病毒2（SARS-CoV-2）。方法 将来自上海市COVID-19患者的3份鼻/咽拭子样本以TPCK胰酶处理,然后接种Vero E6细胞;待大部分细胞出现明显病变时,取细胞培养上清用qRT-PCR法检测病毒核酸,并用反转录PCR扩增病毒受体结合区（RBD）基因片段;将病毒扩增培养后感染接种于96孔板中的Vero E6细胞,观察细胞病变效应,并用免疫荧光法检测病毒蛋白。结果 2份COVID-19患者鼻/咽拭子样本接种的Vero E6细胞出现明显细胞病变效应,细胞培养上清中检测出新复制产生的SARS-CoV-2核酸,扩增出的RBD序列与早期分离出的SARS-CoV-2相应序列完全一致;病毒感染的Vero E6细胞病变迅速,并能与SARS-CoV-2核衣壳蛋白（N蛋白）单克隆抗体、刺突蛋白（S蛋白）单克隆抗体及COVID-19患者恢复期血清发生反应。结论 从2份COVID-19患者鼻/咽拭子样本中成功分离出SARS-CoV-2,为后续开展SARS-CoV-2感染与致病机制研究、防治药物与疫苗的研发奠定了基础。     

不同新型冠状病毒变异株感染的COVID-19潜伏期研究

从新型冠状病毒肺炎（COVID-19）疫情初始至今,COVID-19的病原体新型冠状病毒（SARS-CoV-2）不断进化和变异,产生传播力和毒力变化的变异株,如Alpha（B.1.1.7）、Beta（B.1.351）、Gamma（P.1）、Delta（B.1.617.2）以及Omicron（B.1.1.529）变异株。深入研究不同变异株感染所致的COVID-19潜伏期有助于追溯传染源,确定密切接触者的留验、检疫和医学观察期限,为及时调整COVID-19疫情防控措施提供依据。本文主要综述了国内外感染SARS-CoV-2野生株和不同变异株的COVID-19潜伏期的相关研究,研究发现,感染SARS-CoV-2野生株的潜伏期在4~8 d,中位潜伏期约为5.5 d。感染Beta、Gamma变异株的潜伏期与野生株基本类似,约为5 d。感染Alpha、Delta和Omicron变异株的潜伏期则低于其他毒株,分别为4 d、4 d和3 d。     

Structural basis of SARS-CoV-2 3CLpro and anti-COVID-19 drug discovery from medicinal plants

The recent pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has raised global health concerns. The viral 3-chymotrypsin-like cysteine protease (3CL^pro) enzyme controls coronavirus replication and is essential for its life cycle. 3CL^pro is a proven drug discovery target in the case of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). Recent studies revealed that the genome sequence of SARS-CoV-2 is very similar to that of SARS-CoV. Therefore, herein, we analysed the 3CL^pro sequence, constructed its 3D homology model, and screened it against a medicinal plant library containing 32,297 potential anti-viral phytochemicals/traditional Chinese medicinal compounds. Our analyses revealed that the top nine hits might serve as potential anti- SARS-CoV-2 lead molecules for further optimisation and drug development process to combat COVID-19.     

SARS-CoV-2溯源新进展

从2019年12月~2020年11月19日,COVID-19大流行已导致全球55 928 327例确诊病例,造成1 344 003人死亡。但是,我们对这次疫情的病原体-新型冠状病毒（SARS-CoV-2）的来源仍然未了解清楚。本综述总结和分析SARS-CoV-2溯源研究进展,为进一步的研究提供启示。现有证据表明SARS-CoV-2有可能是在40~70年前由蝙蝠冠状病毒分化而来;该病毒在进化过程中同时存在多种变异及自然选择现象,病毒基因不同区域可能发生不同变异并受到不同的选择压力,这些都增加了病毒溯源的困难性;有多种动物被认为可能是SARS-CoV-2的宿主,包括猫、狮子、老虎、狗、水貂等;SARS-CoV-2可能可由人类传播给动物,且该病毒也可以在动物间互相传播;现有证据不支持该病毒的源头是中国。我们仍未清楚该病毒如何传播到人类,仍然需要更多的研究去探索SARS-CoV-2的来源、宿主、中间宿主及其跨物种传播的机制。     

新型冠状病毒肺炎病区环境及医务人员防护设备表面SARS-CoV-2核酸污染的检测与评价

目的:对武汉某定点医院新型冠状病毒肺炎(corona virus disease 2019,COVID-19)病区内的空气、污染区高频接触物体表面及医务人员防护服表面采样,并检测新型冠状病毒(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)核酸,以明确病区内SARS-CoV-2污染程度,指导感染控制,保证医务人员安全。方法:于2020年3月11—19日,使用便携式生物气溶胶采样器WA-15采集病区内清洁区、缓冲区及污染区的空气样本,应用预湿无菌棉签涂抹法采集污染区高频接触物体表面样本和医务人员防护服表面样本(最外层手套表面以及气管切开操作者正压呼吸防护头套和隔离衣表面),采用实时荧光定量PCR方法检测样本中的SARS-CoV-2核酸。隔离医学观察期间对病区内工作过的医务人员行咽拭子SARS-CoV-2核酸检测,血清SARS-CoV-2 IgM、IgG抗体检测及胸部CT扫描明确医务人员COVID-19感染情况。结果:病区内90个清洁区、缓冲区及污染区空气样本,38个污染区高频接触物体表面样本和16个医务人员防护服表面样本,均未检出SARS-CoV-2核酸。137位在病区参与COVID-19救治工作的医务人员咽拭子SARS-CoV-2核酸检查结果均阴性,血清SARS-CoV-2 IgM、IgG抗体均阴性,胸部CT检查均无COVID-19肺部影像学表现。结论:良好的通风条件、严格环境设施消毒、正确的患者生活习惯指导以及医务人员严格手卫生,是减少隔离病房内病毒气溶胶形成、降低气溶胶含量、避免交叉感染的重要保证。面对未完全掌握的按甲类管理的传染病,医务人员按高级别防护是安全的。     

SARS-CoV-2暴露剂量与COVID-19潜伏期及病情发展趋势的相关性研究

尽管SARS-CoV-2暴露剂量和暴露者机体抵抗力都是受多种因素影响难以确定的变量,但COVID-19的发生是SARS-CoV-2暴露剂量与暴露者机体抵抗力相互作用的结果。本文通过比较中国湖北内外发病情形、湖北之外其他省市不同日期COVID-19发病的潜伏期、以及散发病例与聚集性发病情形,发现SARS-CoV-2感染率高低与疫情时程及潜伏期均相关,显示SARS-CoV-2暴露剂量与是否发病、以及发病后的严重程度均可能具有相关性。从而提示COVID-19的治疗,需要对潜伏期偏短的患者提防其重症化和死亡风险。     

奥密克戎(Omicron)变异株及其对口腔诊疗的潜在影响

严重急性呼吸系统综合征冠状病毒2 (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2)感染引起的2019冠状病毒病(coronavirus disease 2019, COVID-19,我国通称新型冠状病毒肺炎,简称新冠肺炎)疫情已经在全世界蔓延超过两年,每日的新增感染人数及死亡人数仍在持续增长。最新出现的奥密克戎(Omicron)变异株因其刺突蛋白出现多位点突变,导致病毒传染性与致病性发生显著变化,给公共卫生带来了新的挑战。WHO将Omicron变异株列为“需要关注的变异株”(variants of concern, VOC)。SARS-CoV-2及其变异株的传播扰乱了世界范围内的口腔诊疗工作。口腔诊疗过程中,近距离面对面交流、飞沫、气溶胶、接触唾液、血液等,增加了口腔诊疗机构中的传播风险,特别是Omicron等新发变异株的流行,对口腔诊疗带来新的挑战。口腔舌部、黏膜等组织可高表达血管紧张素转换酶2(angiotensin converting enzyme 2, ACE2),ACE2是SARS-CoV-2的结合受...     

新型冠状病毒感染疫情下县域高血压管理的专家建议

目前,我国各省份及境外均出现了新型冠状病毒（SARS-CoV-2）感染疫情。针对我国庞大的高血压患者群体,尤其是更多分布于基层的高血压患者,现提出县域SARS-CoV-2感染下的高血压管理的专家建议。本建议仅限于没有合并SARS-CoV-2感染的高血压患者。     

新型冠状病毒肺炎病区环境及医务人员防护设备表面SARS-CoV-2核酸污染的检测与评价

目的:对武汉某定点医院新型冠状病毒肺炎(corona virus disease 2019,COVID-19)病区内的空气、污染区高频接触物体表面及医务人员防护服表面采样,并检测新型冠状病毒(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)核酸,以明确病区内SARS-CoV-2污染程度,指导感染控制,保证医务人员安全。方法:于2020年3月11—19日,使用便携式生物气溶胶采样器WA-15采集病区内清洁区、缓冲区及污染区的空气样本,应用预湿无菌棉签涂抹法采集污染区高频接触物体表面样本和医务人员防护服表面样本(最外层手套表面以及气管切开操作者正压呼吸防护头套和隔离衣表面),采用实时荧光定量PCR方法检测样本中的SARS-CoV-2核酸。隔离医学观察期间对病区内工作过的医务人员行咽拭子SARS-CoV-2核酸检测,血清SARS-CoV-2 IgM、IgG抗体检测及胸部CT扫描明确医务人员COVID-19感染情况。结果:病区内90个清洁区、缓冲区及污染区空气样本,38个污染区高频接触物体表面样本和16个医务人员防护服表面样本,均未检出SARS-CoV-2核酸。137位在病区参与COVID-19救治工作的医务人员咽拭子SARS-CoV-2核酸检查结果均阴性,血清SARS-CoV-2 IgM、IgG抗体均阴性,胸部CT检查均无COVID-19肺部影像学表现。结论:良好的通风条件、严格环境设施消毒、正确的患者生活习惯指导以及医务人员严格手卫生,是减少隔离病房内病毒气溶胶形成、降低气溶胶含量、避免交叉感染的重要保证。面对未完全掌握的按甲类管理的传染病,医务人员按高级别防护是安全的。     

新型冠状病毒疫苗研究现状以及仿生纳米疫苗研究前景

新型冠状病毒传染病(COVID-19)呈全球流行。接种疫苗是预防新型冠状病毒(SARS-CoV-2)感染的重要手段。不同类型的疫苗或疫苗加强针需要被开发以应对COVID-19疫情。本文综述了新型冠状病毒疫苗的现状以及重点探讨了仿生纳米疫苗的研发前景,希望对后续新冠疫苗的研发提供有益借鉴。