新发现的人细小病毒——博卡病毒

急性呼吸道感染(acute respiratory tract infection,ARTI)是婴幼儿和儿童的常见病、多发病。据估计,全世界每年有400万5岁以下婴幼儿和儿童死于ARTI[1]。多种病原可以引起ARTI,但最常见的还是呼吸道病毒。这些呼吸道病毒主要包括流感病毒、副流感病毒、腺病毒、呼吸道合胞病毒、鼻病毒、冠状病毒等。但是,仍有相当比例的呼吸道感染患者用现有的方法检测不到特异性的病原[2]。近几年,随着分子生物学技术的发展,新的呼吸道病毒不断被发现,包括人偏肺病毒(human metapneumovirus)、人冠状病毒,如SARS、NL63、HKU1等病毒[3,4]。Alland…     

新型冠状病毒反向遗传学技术应用进展研究

冠状病毒是有包膜的、单股正链RNA病毒,基因组长约26~32 kb。人类冠状病毒感染通常引起上呼吸道与下呼吸道疾病,严重程度从普通感冒到严重急性呼吸综合征不等。SARS-CoV-2是2019年开始在全球范围内暴发流行的冠状病毒,通过反向遗传技术对人冠状病毒cDNA进行操作,构建感染性克隆,有助于对冠状病毒基因组分与功能...     

副流感病毒的分子生物学性状及其疫苗的研究进展

副流感病毒是一类不分节段的单股负链RNA病毒，可引起所有年龄组人群的呼吸道感染，尤其可引起婴幼儿及儿童严重呼吸道疾病。本文基于副流感病毒的分子生物学性状就其近年来疫苗的研究进展作一综述。     

SARS病原体特征与临床实验室诊断

SARS的全球性流行带来了严重的公共卫生问题和社会经济问题.目前,在SARS病原体鉴定、基因组结构和序列变异、SARS流行特征和实验室诊断等方面获得了很大的进展.现已证实SARS的病原体为SARS冠状病毒.SARS冠状病毒是一种与原来已知冠状病毒在某些方面类似、但又独具特征的新型冠状病毒,该病毒的起源可能源于野生动物.多个SARS冠状病毒的全基因组核酸序列测定现已完成,在SARS冠状病毒的实验室诊断方面,现已有了免疫学方法检查抗体和分子生物学方法检查病毒RNA.直接检测病毒抗原和定量检测病毒多靶点基因是今后的发展方向.     

一种新发现的呼吸道病毒——雷东多病毒的病原学及流行病学研究进展

雷东多病毒是新发现的一种环状单链DNA病毒, 分为Vientovirus和Brisavirus两个种, 在人呼吸道中普遍存在, 可引起呼吸道系统疾病。本文对雷东多病毒的基因组特征、致病性、流行病学、实验室检测等方面进行综述。     

HIV—1病毒学及分子生物学基本特征研究进展

获得性免疫缺陷综合征 (AIDS)由人类免疫缺陷病毒 (HIV) / 型引起。 HIV属逆转录病毒系慢病毒亚科。慢病毒的特征是引起持续性感染 (急性 /慢性 )。潜伏期较长 ,免疫系统的细胞为主要感染对象 ,如 T细胞和巨噬细胞 ,病毒在感染细胞中引起细胞病变效应 ,例如形成合胞体和细胞死亡。慢病毒 RNA基因组约 1 0 kb左右 ,编码各种蛋白。慢病毒突出的生物学特征是可以感染非分裂细胞 ,其结构与复制的特性可能是免疫系统难以清除感染细胞的主要原因 [1] 。本文仅将 HIV病毒学和分子生物学其中几个重要的结构与特征进行综述。1　HIV-1的基本…     

SARS病毒研究进展

严重急性呼吸综合征 (SevereAcuteRespiratorySyndrome ,SARS)是由SARS病毒引起的一种急性呼吸道传染病 ,主要通过近距离空气飞沫和密切接触传播。SARS病毒是冠状病毒的一个变种 ,以前从未在人类或其它动物中发现。基因组全长约为 3 0Kb ,主要编码五种与病毒侵入、复制有关的结构蛋白 (RNA聚合酶、S、M、E、N蛋白 ) ,这些蛋白质的结构和功能对于今后设计疫苗和抗病毒药物至关重要。到目前为止 ,致病机理还不十分清楚。SARS病毒感染的实验室检测方法主要有细胞培养、分子生物学检测和抗体检测     

广东省严重急性呼吸综合征病毒的分离和鉴定

目的 分离和鉴定引起广东省非典型肺炎的病原体。方法 收集非典型肺炎患者的各种临床标本，用狗肾传代细胞(MDCK)进行病原体分离，并运用血清学和分子生物学方法进行鉴定。结果 用MDCK细胞从非典型性肺炎患者标本中分离到病毒，用SARS病毒聚合酶基因的特异引物，通过巢式聚合酶链反应(nest RT-PCR)，扩增出一个279nt的片段，序列分析结果显示，该序列和目前已知的冠状病毒有39％-65％同源性，和来源于不同地区分离的SARS冠状病毒株(中国北京、香港、台湾和德国、意大利等)在同一个位置(第12个碱基)仅有一个碱基不同，由a→t。间接免疫荧光抗体检测显示，该病毒能够和非典型肺炎患者的恢复期血清呈特异的抗体反应。结论 这种新的冠状病毒是引起广东省非典型肺炎的病原，且能够用MDCK细胞进行分离。     

呼吸道病毒检测方法的研究进展

呼吸道病毒是一组能够通过呼吸道感染引起呼吸系统及其他系统疾病的病毒.常见的呼吸道病毒有正粘病毒科的流感病毒,副粘病毒科的副流感病毒、麻疹病毒、腮腺炎病毒、呼吸道合胞病毒,以及冠状病毒科的冠状病毒,披膜病毒科的风疹病毒和腺病毒科的腺病毒等.近年来新的致病性病毒不断地被发现,如人类偏肺病毒、人博卡病毒、SARS病毒、高致病性禽流感病毒等.对于呼吸道病毒来讲,同一种病毒可引起多种临床症状,不同的病毒可引起同一种临床症状,给临床诊断和治疗造成很大的困难,所以这类病毒的检测确诊对于采取有效的预防和治疗措施极为重要.     

HcoV-NL63——一种新发现的呼吸道感染病毒病原

人冠状病毒NL63(Human coronavirus NL63,HCoV-NL63)是2004年4月荷兰学者vander Hoek L等首先报道发现的一种与呼吸道疾病有关的新的人冠状病毒,它是一单股正链RNA病毒,属于冠状病毒科冠状病毒属。感染后可以引起上、下呼吸道感染,在儿童和免疫力低下的人群中的感染率较高,可与其它病毒合并感染,也可单独感染而引起发病。目前检测HCoV-NL63的方法主要是RT-PCR。     

Studies on the relationship between coronaviruses from the intestinal and respiratory tracts of calves

Summary An immunofluorescence test on smears of nasal epithelial cells was used to detect coronavirus infection in the respiratory tract of calves. Thirteen gnotobiotic calves were infected with coronavirus isolates derived from faeces or respiratory material: virus was detected in faeces and nasal swabs from all animals. In 115 calves from a field survey, there was a significant association between coronavirus excretion from both respiratory and enteric routes in calves with diarrhoea. In a further 12 calves, at necropsy, the predilection sites for coronavirus growth were the distal small intestine, large intestine and the epithelia of the nasal cavity and trachea. Antigen was not found in lung tissue by immunofluoresence or immunoperoxidase staining.Infection with enteric coronavirus induced immunity to reinfection and to heterologous challenge with two coronavirus isolates derived from the respiratory tract. Nine coronaviruses were cultivated, cloned and antisera to three were prepared in pigs. There was complete virus neutralisation in tests with homologous sera and significant cross reactions with the eight other isolates which were of intestinal and respiratory origin. Thus, these bovine coronavirus isolates belonged to the same serotype despite the source of virus.With 3 Figures     

Recent advances in the detection of respiratory virus infection in humans

Respiratory tract viral infection caused by viruses or bacteria is one of the most common diseases in human worldwide, while those caused by emerging viruses, such as the novel coronavirus, 2019-nCoV that caused the pneumonia outbreak in Wuhan, China most recently, have posed great threats to global public health. Identification of the causative viral pathogens of respiratory tract viral infections is important to select an appropriate treatment, save people's lives, stop the epidemics, and avoid unnecessary use of antibiotics. Conventional diagnostic tests, such as the assays for rapid detection of antiviral antibodies or viral antigens, are widely used in many clinical laboratories. With the development of modern technologies, new diagnostic strategies, including multiplex nucleic acid amplification and microarray-based assays, are emerging. This review summarizes currently available and novel emerging diagnostic methods for the detection of common respiratory viruses, such as influenza virus, human respiratory syncytial virus, coronavirus, human adenovirus, and human rhinovirus. Multiplex assays for simultaneous detection of multiple respiratory viruses are also described. It is anticipated that such data will assist researchers and clinicians to develop appropriate diagnostic strategies for timely and effective detection of respiratory virus infections.     

Enhanced identification of viral and atypical bacterial pathogens in lower respiratory tract samples with nucleic acid amplification tests

The advantages of nucleic acid amplification tests (NAT) over conventional methods for the detection of pathogens in lower respiratory tract samples have not been established. NAT for respiratory pathogens were performed on 439 endotracheal tube (ETT) and bronchoalveolar lavage (BAL) samples. A potential pathogen was detected in 87 samples. Of 22 samples that tested positive by conventional methods, 15 tested positive for the same pathogen by NAT, 1 tested positive for a different pathogen, 2 had co-infections identified only by NAT, and 4 tested negative by NAT. An additional 73 pathogens were detected by NAT in 65 samples including 30 pathogens that were missed by conventional methods (19 adenovirus, 6 respiratory syncytial virus, 3 parainfluenza virus 1-4, 2 influenza A), 41 pathogens not routinely identified by conventional methods in most laboratories (23 rhinovirus, 8 human coronavirus OC43, 5 human metapneumovirus (hMPV), 2 human coronavirus 229E, 2 human coronavirus NL63, 1 Chlamydophila pneumoniae) and 2 pathogens from samples where no respiratory virus testing was requested (1 influenza A, 1 parainfluenza virus). Four of 52 patients who had multiple BAL samples submitted on the same day had negative and positive results by NAT on different samples. NAT improves detection of potential pathogens from ETT and BAL samples.     

Development of a respiratory virus panel test for detection of twenty human respiratory viruses by use of multiplex PCR and a fluid microbead-based assay

Virology laboratories historically have used direct fluorescent-antibody assay (DFA) and culture to detect six or seven respiratory viruses. Following the discovery of five new human respiratory viruses since 2000, there is an increasing need for diagnostic tests to detect these emerging viruses. We have developed a new test that can detect 20 different respiratory virus types/subtypes in a single 5-h test. The assay employs multiplex PCR using 14 virus-specific primer pairs, followed by a multiplexed target-specific primer extension (TSPE) reaction using 21 primers for specific respiratory virus types and subtypes. TSPE products were sorted and identified by using a fluid microsphere-based array (Universal Array; TmBioscience Corporation, Toronto, Canada) and the Luminex x-MAP system. The assay detected influenza A and B viruses; influenza A virus subtypes H1, H3, and H5 (including subtype H5N1 of the Asian lineage); parainfluenza virus types 1, 2, 3, and 4; respiratory syncytial virus types A and B; adenovirus; metapneumovirus; rhinovirus; enterovirus; and coronaviruses OC43, 229E, severe acute respiratory syndrome coronavirus, NL63, and HKU1. In a prospective evaluation using 294 nasopharyngeal swab specimens, DFA/culture detected 119 positives and the respiratory virus panel (RVP) test detected 112 positives, for a sensitivity of 97%. The RVP test detected an additional 61 positive specimens that either were not detected by DFA/culture or were positive for viruses not tested for by DFA/culture. After resolution of discordant results by using a second unique PCR assay and by using a combined reference standard of positivity, the RVP test detected 180 of 183 true positives, for a sensitivity of 98.5%, whereas DFA and culture detected only 126 of 183 true positives, for a sensitivity of 68.8%. The RVP test should improve the capabilities of hospital and public health laboratories for diagnosing viral respiratory tract infections and should assist public health agencies in identifying etiologic agents in respiratory tract infection outbreaks.     

The neuroinvasive potential of SARS-CoV2 may play a role in the respiratory failure of COVID-19 patients

Following the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), another highly pathogenic coronavirus named SARS-CoV-2 (previously known as 2019-nCoV) emerged in December 2019 in Wuhan, China, and rapidly spreads around the world. This virus shares highly homological sequence with SARS-CoV, and causes acute, highly lethal pneumonia coronavirus disease 2019 (COVID-19) with clinical symptoms similar to those reported for SARS-CoV and MERS-CoV. The most characteristic symptom of patients with COVID-19 is respiratory distress, and most of the patients admitted to the intensive care could not breathe spontaneously. Additionally, some patients with COVID-19 also showed neurologic signs, such as headache, nausea, and vomiting. Increasing evidence shows that coronaviruses are not always confined to the respiratory tract and that they may also invade the central nervous system inducing neurological diseases. The infection of SARS-CoV has been reported in the brains from both patients and experimental animals, where the brainstem was heavily infected. Furthermore, some coronaviruses have been demonstrated able to spread via a synapse-connected route to the medullary cardiorespiratory center from the mechanoreceptors and chemoreceptors in the lung and lower respiratory airways. Considering the high similarity between SARS-CoV and SARS-CoV2, it remains to make clear whether the potential invasion of SARS-CoV2 is partially responsible for the acute respiratory failure of patients with COVID-19. Awareness of this may have a guiding significance for the prevention and treatment of the SARS-CoV-2-induced respiratory failure.     

Comparison of the FilmArray RP,Verigene RV+, and Prodesse ProFLU+/FAST+ Multiplex Platforms for Detection of Influenza Viruses in Clinical Samples from the 2011-2012 Influenza Season in Belgium

Respiratory tract infections (RTIs) are caused by a plethora of viral and bacterial pathogens. In particular, lower RTIs are a leading cause of hospitalization and mortality. Timely detection of the infecting respiratory pathogens is crucial to optimize treatment and care. In this study, three U.S. Food and Drug Administration-approved molecular multiplex platforms (Prodesse ProFLU+/FAST+, FilmArray RP, and Verigene RV+) were evaluated for influenza virus detection in 171 clinical samples collected during the Belgian 2011-2012 influenza season. Sampling was done using mid-turbinate flocked swabs, and the collected samples were stored in universal transport medium. The amount of viral RNA present in the swab samples ranged between 3.07 and 8.82 log₁₀ copies/ml. Sixty samples were concordant influenza A virus positive, and 8 samples were found to be concordant influenza B virus positive. Other respiratory viruses that were detected included human rhinovirus/enterovirus, respiratory syncytial virus, parainfluenza virus type 1, human metapneumovirus, and coronavirus NL63. Twenty-five samples yielded discordant results across the various assays which required further characterization by sequencing. The FilmArray RP and Prodesse ProFLU+/FAST+ assays were convenient to perform with regard to sensitivity, ease of use, and low percentages of invalid results. Although the limit of sensitivity is of utmost importance, many other factors should be taken into account in selecting the most convenient molecular diagnostic assay for the detection of respiratory pathogens in clinical samples.     

Prevention and treatment of COVID-19 disease by controlled modulation of innate immunity

The recent outbreak of coronavirus disease 2019 (COVID-19), triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses an enormous threat to global public health and economies. Human coronaviruses normally cause no or mild respiratory disease but in the past two decades, potentially fatal coronavirus infections have emerged, causing respiratory tract illnesses such as pneumonia and bronchitis. These include severe acute respiratory syndrome coronavirus (SARS-CoV), followed by the Middle East respiratory syndrome coronavirus (MERS-CoV), and recently the SARS-CoV-2 coronavirus outbreak that emerged in Wuhan, China, in December 2019. Currently, most COVID-19 patients receive traditional supportive care including breathing assistance. To halt the ongoing spread of the pandemic SARS-CoV-2 coronavirus and rescue individual patients, established drugs and new therapies are under evaluation. Since it will be some time until a safe and effective vaccine will be available, the immediate priority is to harness innate immunity to accelerate early antiviral immune responses. Second, since excessive inflammation is a major cause of pathology, targeted anti-inflammatory responses are being evaluated to reduce inflammation-induced damage to the respiratory tract and cytokine storms. Here, we highlight prominent immunotherapies at various stages of development that aim for augmented anti-coronavirus immunity and reduction of pathological inflammation.     

Does SARS-CoV-2 has a longer incubation period than SARS and MERS?

The outbreak of a novel coronavirus (SARS-CoV-2) since December 2019 in Wuhan, the major transportation hub in central China, became an emergency of major international concern. While several etiological studies have begun to reveal the specific biological features of this virus, the epidemic characteristics need to be elucidated. Notably, a long incubation time was reported to be associated with SARS-CoV-2 infection, leading to adjustments in screening and control policies. To avoid the risk of virus spread, all potentially exposed subjects are required to be isolated for 14 days, which is the longest predicted incubation time. However, based on our analysis of a larger dataset available so far, we find there is no observable difference between the incubation time for SARS-CoV-2, severe acute respiratory syndrome coronavirus (SARS-CoV), and middle east respiratory syndrome coronavirus (MERS-CoV), highlighting the need for larger and well-annotated datasets.