关键词： Rabies virus   Rabies virus-related viruses   Bats  

摘要： The recognition that viruses related to rabies virus cause rabies in humans has stimulated research into the relationships, geographic distribution and natural histories of these viruses. This paper reviews what is known of these fascinating viruses and the complexity of prevention and treatment of the disease they cause. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Nipah virus   epidemic enhancement   infectious disease dynamics   emerging pathogens   zoonosis   flying fox  

摘要： Emerging zoonoses threaten global health, yet the processes by which they emerge are complex and poorly understood. Nipah virus (NiV) is an important threat owing to its broad host and geographical range, high case fatality, potential for human-to-human transmission and lack of effective prevention or therapies. Here, we investigate the origin of the first identified outbreak of NiV encephalitis in Malaysia and Singapore. We analyse data on livestock production from the index site (a commercial pig farm in Malaysia) prior to and during the outbreak, on Malaysian agricultural production, and from surveys of NiV's wildlife reservoir (flying foxes). Our analyses suggest that repeated introduction of NiV from wildlife changed infection dynamics in pigs. Initial viral introduction produced an explosive epizootic that drove itself to extinction but primed the population for enzootic persistence upon reintroduction of the virus. The resultant within-farm persistence permitted regional spread and increased the number of human infections. This study refutes an earlier hypothesis that anomalous El Nino Southern Oscillation-related climatic conditions drove emergence and suggests that priming for persistence drove the emergence of a novel zoonotic pathogen. Thus, we provide empirical evidence for a causative mechanism previously proposed as a precursor to widespread infection with H5N1 avian influenza and other emerging pathogens.

关键词： 蝙蝠蛾被毛孢   免疫调节  

摘要： 目的研究蝙蝠蛾被毛孢对小鼠免疫功能的影响。方法以KM种小鼠为研究对象,将小鼠分为空白对照组、低剂量组(110mg/kg)和中剂量(220mg/kg)、高剂量组(450mg/kg),连续灌胃用药28d,进行小鼠碳粒廓清试验、血清溶血素试验和二硝基氟苯(DNFB)诱导小鼠迟发性变态反应(DTH)。结果与空白对照组相比,蝙蝠蛾被毛孢在220、450mg/kg剂量下,能明显增强小鼠单核-巨噬细胞吞噬功能、体液免疫功能和细胞免疫功能。结论蝙蝠蛾被毛孢有明显的免疫促进作用。

关键词： 严重急性呼吸道综合症   SARS冠状病毒   遗传进化   受体利用  

摘要： 严重急性呼吸道综合症(Severe Acute Respiratory Syndrome,SARS)是一种动物源性疾病,其病原体是一种新型的冠状病毒-SARS冠状病毒(SARScoronavirus,SARS-CoV)。在蝙蝠体内发现的蝙蝠SARS样冠状病毒(SARS-likecoronavirus,SL-CoV)与SARS-CoV基因组高度相似,但是不能利用SARS-CoV的受体ACE2入侵细胞,说明目前发现的蝙蝠SL-CoV还不是SARS-CoV的直接祖先。本论文进一步对SARS-CoV的直接来源、蝙蝠SL-CoV基因组遗传进化和受体利用进行了研究,取得结果如下:　　 1.调查了中国大陆南方蝙蝠中冠状病毒的流行情况,发现了一株与SARS-CoV同源性极高的新型蝙蝠SL-CoV,命名为SHC014。SHC014基因组的全长为29769nt,其结构与2b类代表性冠状病毒非常相似。与已知蝙蝠SL-CoV相比,SHC014拥有一个较长的ORF3b;与人SARS-CoV相比,SHC014有一个完整的ORF8。SHC014的基因组全核苷酸序列与人或果子狸SARS-CoV相似性最高,达到了95.2%,其pla、S、ORF3、N基因与人或果子狸SARS-CoV最近,而plb、E、M、ORF6、ORF7、ORF8和3’末端茎环结构样基序(Stem-loop2-likemotif,s2m)与蝙蝠SL-CoV最相似。在主要变异区中,SHC014的S蛋白受体结合区(Receptor Binding Domain,RBD)无其它蝙蝠SL-CoV特有的缺失,ORF3b在114个氨基酸中与人SARS-CoV只有一个位点的差异。系统进化分析表明,SHC014是目前已知蝙蝠SL-CoV中与SARS-CoV亲缘关系最近的一株。重组分析显示SARS-CoV不是由SHC014与已知的蝙蝠SL-CoV直接重组而来。此外,在菊头蝠、鼠耳蝠和翼蝠中检测到了与蝙蝠存在一定宿主特异性的冠状病毒,系统进化上隶属于α冠状病毒属的1b类和β冠状病毒属的2b类冠状病毒。　　 2.构建了SHC014S蛋白的假病毒系统,以及基于人SARS-CoV BJ01和蝙蝠SL-CoV Rp3的S为骨架,嵌合有SHC014 RBD区的嵌合体和点突变体,研究了这些假病毒利用人ACE2入侵细胞的能力。假病毒感染实验表明SHC014不能利用人ACE2分子,但是嵌合有SHC014 RBD区的BJ01 S可以介导假病毒的入侵,从分子水平上证明了SHC014与SARS-CoV的RBD区具有相似的功能。

关键词： 乙脑病毒   蝙蝠   分离   鉴定   基因组   序列分析  

摘要： 研究背景和目的流行性乙型脑炎(Japanese encephalitis B,JE,简称乙脑)也称日本脑炎,是由流行性乙型脑炎病毒(Japanese encephalitis virus,JEV,简称乙脑病毒)引起,经蚊传播的人畜共患的中枢神经系统急性传染病。乙脑病毒是热带和亚热带地区最普遍的节肢动物媒介病毒之一,属于黄病毒科,黄病毒属病毒,为单股正链RNA病毒,RNA大小约为11kb,含有一个长的开放阅读框架(ORF)编码3个结构蛋白(C蛋白、PrM/M蛋白、E蛋白)和7个非结构蛋白(NS1、NS2a、NS2b、NS3、NS4a、NS4b和NS5),分五个基因型,一个血清型。乙脑流行于亚洲东部、南部及太平洋沿岸,全球每年大约有35000～50000例病例,其中约10000～15000例死亡。乙脑的受害者大多是儿童,约50%的幸存者有神经系统后遗症。乙脑在世界许多国家均有流行,我国是高发地区,全国除了青海以外的省市均有乙脑病例的报道,局部地区有爆发或者流行。乙脑病毒的动物储存宿主主要是猪和鸟。蝙蝠已经被认识到是一种重要的病毒储存宿主。中国和日本的一些研究表明在蝙蝠体内能检测到乙脑病毒或乙脑病毒的血清抗体。中国学者有从蝙蝠体内分离出乙型脑炎病毒的报道。近年来,中国云南省的4株乙脑病毒蝙蝠分离株(B58、GB30、HB49和HN97)的基因组序列已被确认,这4株乙脑病毒蝙蝠分离株均属于GⅢ型。然而,蝙蝠在人畜乙脑传播中的作用尚不清楚。鉴于乙脑病毒的基因型有一定的地区和时间分布特征,对蝙蝠乙脑病毒株的基因型以及其与人、猪、蚊分离株的基因同源性进行分析,可有助于探讨蝙蝠在乙脑病毒传播中的作用。本研究中,我们对本实验室采集自中国广东、海南、湖南的普通长翼蝠、小黄蝠、中华菊头蝠、大足鼠耳蝠这4个蝙蝠种的9份可疑乙脑病毒阳性标本进行了乙脑病毒分离、鉴定以及基因组序列的确定及分析。同时,我们从GenBank中选取了代表不同时间、地域、宿主的其他乙脑病毒株,包括23个乙脑病毒基因组全序列、12个E蛋白的基因序列、6个M蛋白的基因序列及1个NS5蛋白的基因序列,与我们的分离株一起进行基因序列的比较和分析。本研究目的是通过上述分析,初步阐明蝙蝠在乙脑病毒传播的作用。研究方法1蝙蝠乙脑病毒株的分离单层BHK-21细胞接种9份可疑蝙蝠乙脑病毒阳性标本(GD1、HN1、HN2、HN3、YY1、YY2、YY3、SY87、YY158),持续观察7天,并设本实验室保存的中山株(Nakayama)为阳性对照,正常细胞为空白对照。7天后收取细胞病毒液,于-80℃冰箱中冻存。每组5只2～3日龄NIH乳鼠分别经颅接种0.02ml可疑蝙蝠乙脑病毒阳性标本(GD1、HN1、HN2、HN3、YY1、YY2、YY3、SY87、YY158),设Nakayama株作阳性对照,阴性对照接种DEPC水。观察记录乳鼠是否出现拒乳、弓背、行动迟缓、侧卧、抽搐、嗜睡、偏瘫等症状以及死亡情况。接种后24h内每2h观察1次,24h后一天观察3次,持续14天。无菌操作解剖乳鼠取脑组织保存于RNAlater,置于-80℃冰箱。2蝙蝠乙脑病毒株的鉴定2.1蝙蝠乙脑病毒特异性核酸的检测将染毒BHK-21细胞悬液和染毒乳鼠脑组织进行RNA提取、逆转录、PCR,可疑阳性PCR产物送公司测全序。2.2蝙蝠乙脑病毒滴度的测定采用毒力稳定的第三代盲传病毒细胞液,用细胞全培液将病毒液作连续10倍的稀释从10-1到10-8,每一稀释度接种8孔,设阳性对照和空白对照。显微镜下观察记录病变孔数。采用Reed-Muench法计算TCID50。2.3间接免疫荧光参照文献以及抗体试剂盒说明书(Abcam)选择抗体工作浓度进行检测。2.4蝙蝠乙脑病毒半数致死量(LD50)的测定乳鼠以窝为单位分成12组,每组5～6只,采用经颅接种0.02ml的方式。一组为阳性对照组接种中山株(Nakayama),一组为阴性对照组接种5%MEM细胞培养液,另外十组分别接种GD1和HN2株10-0～10-4的病毒液。观察记录死亡情况,采用改良寇氏法计算半数致死量。取10-2组死亡鼠脑进行RNA的提取,RT-PCR检测乙脑病毒E基因的目的片段。2.5病理组织观察10-0GD1、10-0HN2组、阳性对照组和阴性对照组乳鼠死亡后立即取脑保存于10%福尔马林中,制成石蜡切片进行观察。3蝙蝠乙脑病毒株基因组的分析根据分离的国家、年份、宿主从Genbank中选出23个乙脑病毒基因组序列、12个E蛋白的基因序列、6个M蛋白的基因序列及1个NS5蛋白的基因序列作为比较的基因序列。采用MEGA4.0软件进行多序列比对。采用MegAlign软件对核苷酸的相似性、氨基酸序列的相似性进行计算。采用DNAMAN软件预测RNA二级结构。采用Geneious 5.5.6显示基

关键词： Animals   Australia   Australia   Chiroptera/urine   Chiroptera/virology   Geography   Hendra Virus/physiology   Seasons   Virus Diseases/urine   Virus Diseases/virology  

摘要： Hendra virus is a recently emerged zoonotic agent in Australia. Since first described in 1994, the virus has spilled from its wildlife reservoir (pteropid fruit bats, or 'flying foxes') on multiple occasions causing equine and human fatalities. We undertook a three-year longitudinal study to detect virus in the urine of free-living flying foxes (a putative route of excretion) to investigate Hendra virus infection dynamics. Pooled urine samples collected off plastic sheets placed beneath roosting flying foxes were screened for Hendra virus genome by quantitative RT-PCR, using a set of primers and probe derived from the matrix protein gene. A total of 1672 pooled urine samples from 67 sampling events was collected and tested between 1 July 2008 and 30 June 2011, with 25% of sampling events and 2.5% of urine samples yielding detections. The proportion of positive samples was statistically associated with year and location. The findings indicate that Hendra virus excretion occurs periodically rather than continuously, and in geographically disparate flying fox populations in the state of Queensland. The lack of any detection in the Northern Territory suggests prevalence may vary across the range of flying foxes in Australia. Finally, our findings suggest that flying foxes can excrete virus at any time of year, and that the apparent seasonal clustering of Hendra virus incidents in horses and associated humans (70% have occurred June to October) reflects factors other than the presence of virus. Identification of these factors will strengthen risk minimization strategies for horses and ultimately humans.

摘要： For the past 10-15 years, bats have attracted growing attention as reservoirs of emerging zoonotic viruses. This has been due to a combination of factors including the emergence of highly virulent zoonotic pathogens, such as Hendra, Nipah, SARS and Ebola viruses, and the high rate of detection of a large number of previously unknown viral sequences in bat specimens. As bats have ancient evolutionary origins and are the only flying mammals, it has been hypothesized that some of their unique biological features may have made them especially suitable hosts for different viruses. So the question Are bats different, special or exceptional?' has become a focal point in the field of virology, bat biology and virus-host co-evolution. In this brief review, we examine the topic in a relatively unconventional way, that is, our discussion will be based on both scientific discoveries and theoretical predictions. This approach was chosen partially because the data in this field are so limited that it is impossible to conduct a useful review based on published results only and also because we believe it is important to provoke original, speculative or even controversial ideas or theories in this important field of research.

关键词： Interferons   Fruit bats   Bats   O'nyong'nyong virus   Cell cultures   Viral replication   Reverse transcriptase-polymerase chain reaction   Rift Valley fever virus  

摘要： Bats harbor several highly pathogenic zoonotic viruses including Rabies, Marburg, and henipaviruses, without overt clinical symptoms in the animals. It has been suspected that bats might have evolved particularly effective mechanisms to suppress viral replication. Here, we investigated interferon (IFN) response, -induction, -secretion and -signaling in epithelial-like cells of the relevant and abundant African fruit bat species, Eidolon helvum (E. helvum). Immortalized cell lines were generated;their potential to induce and react on IFN was confirmed, and biological assays were adapted to application in bat cell cultures, enabling comparison of landmark IFN properties with that of common mammalian cell lines. E. helvum cells were fully capable of reacting to viral and artificial IFN stimuli. E. helvum cells showed highest IFN mRNA induction, highly productive IFN protein secretion, and evidence of efficient IFN stimulated gene induction. In an Alphavirus infection model, O'nyong-nyong virus exhibited strong IFN induction but evaded the IFN response by translational rather than transcriptional shutoff, similar to other Alphavirus infections. These novel IFN-competent cell lines will allow comparative research on zoonotic, bat-borne viruses in order to model mechanisms of viral maintenance and emergence in bat reservoirs.

关键词： VIRAL proteins   GLYCOPROTEINS   EBOLA virus disease   COMPARATIVE studies   PROTEIN-protein interactions   HEMORRHAGIC fever   BATS as laboratory animals  

摘要： Infection with Ebola virus (EBOV) causes hemorrhagic fever in humans with high case-fatality rates. The EBOV-glycoprotein (EBOV-GP) facilitates viral entry and promotes viral release from human cells. African fruit bats are believed not to develop disease upon EBOV infection and have been proposed as a natural reservoir of EBOV. We compared EBOV-GP interactions with human cells and cells from African fruit bats. We found that susceptibility to EBOV-GP-dependent infection was not limited to bat cells from potential reservoir species, and we observed that GP displayed similar biological properties in human and bat cells. The only exception was GP localization, which was to a greater extent intracellular in bat cells as compared to human cells. Collectively, our results suggest that GP interactions with fruit bat and human cells are similar and do not limit EBOV tropism for certain bat species.