首次从新疆无名热病人分离到8株新环状病毒（BANNA）

从新疆境内的生产建设兵团124团采集到不明原因发烧病人血清98份,分离到8株病毒。感染2～4日龄乳小白鼠和三周龄小白鼠不发病。可引起C6/36细胞病变。电镜观察病毒为球形无囊膜颗粒,直径63～69nm,核衣壳直径为49～54um。超薄切片在感染细胞中常见到大量颗粒状包涵体,磷钨酸负染可见到排列整齐的壳粒结构,显示了典型的环状病毒形态特征。该病毒对酸、氯仿、胰蛋白酶及热敏感;1.1MMgCl_2在50℃作用15分钟可使其感染力提高,在-30℃作用1小时可使其感染力丧失;抵抗乙醚和5-碘脱氧尿苷。血清学鉴定,新分离病毒与披膜病毒科(Togaviridae)、黄病毒科(Flaviviridae)及布尼亚病毒科(Banyaviridae)的某些病毒的免疫腹水及免疫血清都不发生反应。与新环病毒(BANNA)的免疫腹水及免疫血清发生反应。用新环病毒酶标单克隆抗体(McAb)做酶标中和试验为阳性,中和指数为1023.3～18620.9。经初步鉴定,分离的8株病毒的抗原性与近年从我国南方分离的新环状病毒(BANNA)相一致。     

从新疆首次分离出20株甲属披膜病毒

1990年3月至1991年8月,用乳鼠及RHK细胞等从新疆西部和北部地区采集的7种20000余只分离到病毒7株,从新疆北部地区采集的蜱7种2300余只分离到病毒13株,共20株。其中从赫坎按蚊 Anopheles hyrcanus分离3株,从尖音库蚊 Culex pipiens pipiens分离2株,从凶小库蚊 Culexmodestus分离2株;从全沟硬蜱Ixodes persulcatus分离11株,从边缘革蜱 Dermacentor marginatus分离2株。电镜检查该病毒为球形有囊膜颗粒,直径为57±1.5nm左右。用分离的20株病毒感染BHK、Vero及C6/36传代细胞,均可在24～72小时内致细胞病变;病毒以脑内、皮下或腹腔途经感染2～4日龄乳小白鼠2～6天规律致死,3周龄小白鼠3～7天规律致死。病毒抵抗5-碘脱氧尿苷(5～Idu),对酸、热、乙醚敏感。酶免疫(ELISA-BHK)检测20株病毒只与甲属披膜病毒有反应。经初步鉴定为甲属披膜病毒(Alpha virus)。     

云南森林脑炎病毒生物学性状研究

1989年从云南省怒江州捕获的两组卵形硬蜱和一高热患者血中分离到3株病毒,对乳小白鼠和鸡胚敏感,并能在多种组织培养细胞上增殖产生病变。能凝集多种动物红细胞,血凝最适pH为6.2和6.6。电镜观察病毒呈球形,有包膜,直径40～62nm.不耐酸,不耐乙醚,属RNA病毒。保护力试验表明森林脑炎病毒免疫血清对新分离株有保护作用,经交叉血抑试验、交叉中和试验鉴定属披膜病毒科黄病毒属蜱媒脑炎亚组中的森林脑炎病毒。     

脑型EHF患者脑脊液中病毒分离及其生物学性状的初步研究

<正> 我们用环状沉淀试验(RPT)、SPA协同凝集试验(CO-SPA)和ELISA从2例典型脑型EHF患者脑脊液(CSF)中查到病毒抗原(EHFV-Ag),并用Vero-E6细胞从其中1例的CSF中分离到一株可稳定传代的病毒.使用各种免疫血清和单克隆抗体     

新疆阿勒泰山地蜱传脑炎疫源地调查北大核心CSCD

目的调查新疆阿勒泰山地蜱传脑炎疫源地特征,分离鉴定蜱传脑炎病毒。方法通过家畜体表捡法采集寄生蜱;利用间接免疫荧光法检测当地健康人群血清中蜱传脑炎病毒IgG抗体;通过将蜱研磨液接种实验小鼠进行病原动物分离;通过接种BHK-21细胞对蜱传脑炎病毒进行分离培养;利用RT-PCR方法对病毒E蛋白基因片段进行扩增和测序,通过序列分析明确病毒系统进化特征。结果新疆阿勒泰山地白哈巴地区分布有2种蜱,森林革蜱为优势种(55.6%),其次为边缘革蜱(44.4%);当地人群蜱传脑炎IgG抗体阳性率5.31%(6/113);通过动物试验和细胞分离培养,从森林革蜱中分离出一株森林脑炎病毒;对病毒E蛋白基因序列的系统进化分析表明,蜱传脑炎病毒阿勒泰分离株属于远东亚型。结论首次从病原学上证实新疆阿勒泰山地存在蜱传脑炎疫源地,媒介为森林革蜱,病毒流行株为远东亚型。     

新疆阿勒泰山地蜱传脑炎疫源地调查

目的 调查新疆阿勒泰山地蜱传脑炎疫源地特征,分离鉴定蜱传脑炎病毒。方法 通过家畜体表捡法采集寄生蜱;利用间接免疫荧光法检测当地健康人群血清中蜱传脑炎病毒IgG抗体;通过将蜱研磨液接种实验小鼠进行病原动物分离;通过接种BHK-21细胞对蜱传脑炎病毒进行分离培养;利用RT-PCR方法对病毒E蛋白基因片段进行扩增和测序,通过序列分析明确病毒系统进化特征。结果 新疆阿勒泰山地白哈巴地区分布有2种蜱,森林革蜱为优势种(55.6%),其次为边缘革蜱(44.4%);当地人群蜱传脑炎IgG抗体阳性率5.31%(6/113);通过动物试验和细胞分离培养,从森林革蜱中分离出一株森林脑炎病毒;对病毒E蛋白基因序列的系统进化分析表明,蜱传脑炎病毒阿勒泰分离株属于远东亚型。结论 首次从病原学上证实新疆阿勒泰山地存在蜱传脑炎疫源地,媒介为森林革蜱,病毒流行株为远东亚型。     

河南省南阳地区黄牛狂犬病病毒的分离和鉴定

应用鼠脑传代,从具有神经症状的病牛脑组织中分离获得5株病毒,经电子显微镜观察呈典型弹状病毒样粒子。用抗狂犬病毒CVS(狂大病毒1型代表株)免疫血清作ELISA检测及小鼠中和试验,证明分离株病毒为狂大病毒。用狂犬病相关病毒Lagos bat(狂犬病毒2型)、Mokola(狂犬病毒3型)和Duvenhage(狂犬病毒4型)免疫血清对分离株病毒作交叉中和试验,结果发现分离株病毒与Duvenhage有较密切的抗原联系,而与Lagos bat及Mokola病毒没有抗原联系。用自制狂犬病毒“核蛋白”单克隆抗体作夹心间接ELISA检测分离株病毒的感染鼠脑均呈阳性反应,5株病毒与CVS及其互相之间没有明显差异。结论认为,由河南省黄牛分离的病毒为狂犬病毒。     

西伯利亚立克次体中国分离株超微结构的研究

对西伯利亚立克次体中国分离株W—88(人株),JH—74(草原革蜱株),TO—88(草原革蜱蜱卵株),BJ—90(中华革蜱株)及国际标准株(西伯利亚立克次体246株)进行扫描电镜和超薄切片免疫电镜观察。结果显示中国株与国际株具有相似的外部形态和内部超微结构。可见到立克次体细胞外表的粘液层和微荚膜;细胞包膜的细胞壁和胞浆膜;胞内结构的DNA丝和核糖体。在固定液中加入相应的免疫血清用钌红细胞化学染色,在立克次体表面可见有肥厚的纤维状物(亚晶格状表面层)围绕的粘液层,经乙醚提取的立克次体标本粘液层消失,而用泛影(?)胺密度梯度离心纯化的立克次体标本仍有粘液层存在,此为进一步研究其化学成分和功能提供了必要条件。     

1株新型肠道病毒的生物学特性鉴定

目的从1例急性肝炎患儿粪便标本中分离到1株新型肠道病毒,鉴定其生物学特性。方法采用细胞培养、动物试验、中和试验、电子显微镜观察和分子生物学等技术进行鉴定。结果该病毒对乙醚不敏感,在pH3．0及37℃ 60min条件下稳定,56℃30min可以被灭活;能在A549和RD细胞中稳定传代,并致细胞病变;不能被已有肠道病毒免疫血清中和;小白鼠乳鼠对该病毒不敏感;电子显徽镜下可见27-30nm的肠道病毒样颗粒;部分核苷酸序列分析表明,病毒VPI区核苷酸序列与肠道病毒89型的同源性为87％。与其他病毒无有意义的同源性。结论该病毒的生物学特性与肠道病毒相似,但其抗原性和核苷酸序列等与已知肠道病毒有较大差异,可能属于肠道病毒89型的1个新亚型。     

从新疆首次分离到26株新环状病毒

1990年从新疆境内生产建设兵团124团医院采集不明原因发烧病人血清98份,分离到病毒8株;从乌苏县古尔图牧场采集病牛血清3份,分离到病毒1株;从博乐、特克斯、察布查尔、新源及巩留等县共采集各种蜱(主要有全沟硬蜱、森林革蜱、亚洲     

云南省景洪市虫媒病毒调查分析

近１０多年来，先后从云南省景洪市各乡镇的当地病人、猪、蝙蝠和蚊虫体内分离出乙型脑炎病毒２２株，从白纹伊蚊中分离到登革４型病毒１株，从蝙蝠和蚊体内分离到基孔肯雅病毒５株，从患急性期血液中分离到辛德毕斯病毒１株，从发热病人血液、脑炎病人脑脊液、猪血清和牛血清中分离到新环状病毒４７株，从黄胸鼠肺脏中检查出流行性出血热病毒抗原阳性６份；人群、猪恒河猴或鼠类血清中亦检出上述６种病毒的抗体，表明景洪市存在乙     

Inhibition of Orbivirus Replication by Fluvastatin and Identification of the Key Elements of the Mevalonate Pathway Involved

Statin derivatives can inhibit the replication of a range of viruses, including hepatitis C virus (HCV, Hepacivirus), dengue virus (Flavivirus), African swine fever virus (Asfarviridae) and poliovirus (Picornaviridae). We assess the antiviral effect of fluvastatin in cells infected with orbiviruses (bluetongue virus (BTV) and Great Island virus (GIV)). The synthesis of orbivirus outer-capsid protein VP2 (detected by confocal immunofluorescence imaging) was used to assess levels of virus replication, showing a reduction in fluvastatin-treated cells. A reduction in virus titres of ~1.7 log (98%) in fluvastatin-treated cells was detected by a plaque assay. We have previously identified a fourth non-structural protein (NS4) of BTV and GIV, showing that it interacts with lipid droplets in infected cells. Fluvastatin, which inhibits 3-hydroxy 3-methyl glutaryl CoA reductase in the mevalonic acid pathway, disrupts these NS4 interactions. These findings highlight the role of the lipid pathways in orbivirus replication and suggest a greater role for the membrane-enveloped orbivirus particles than previously recognised. Chemical intermediates of the mevalonic acid pathway were used to assess their potential to rescue orbivirus replication. Pre-treatment of IFNAR^(−/−) mice with fluvastatin promoted their survival upon challenge with live BTV, although only limited protection was observed.     

Biology of Arboledas virus, a new phlebotomus fever serogroup virus (Bunyaviridae: Phlebovirus) isolated from sand flies in Colombia

Six isolates of a new phlebotomus fever serogroup virus, designated Arboledas virus, were obtained from sand flies (Lutzomyia spp.) collected in northeastern Colombia. One of the isolates was made from a pool of male sand flies. By immunofluorescence, Arboledas virus is related to Caimito and Pacui viruses; by neutralization test, it is distinct. Arboledas virus neutralizing antibodies were found in the sera of opossums (Didelphis marsupialis) and humans living in the study area. D. marsupialis inoculated with the virus developed a viremia of four days' duration, and sand flies (Lutzomyia gomezi) feeding on a viremic opossum were readily infected. Transovarial transmission of Arboledas virus was also demonstrated in experimentally infected Lu. gomezi. Results of the above laboratory studies suggest that Arboledas virus is maintained in nature by two mechanisms: vertical (transovarial) transmission in the insect vector, and an alternating marsupial-sand fly cycle. The implications of this complex maintenance cycle for other phleboviruses are discussed.     

Effective propagation of various type D retroviruses in human lymphoblastoid Raji cells

Type D retroviruses belong to viruses which often have a low titer in virus-reproducing cell-systems. In search of better conditions for virus propagation, Raji cells (an EBV-genome carrying human B-cell line) were infected with different isolates of type D retroviruses. as demonstrated by electron microscopy all of the viruses showed a very good and stable virus production during long term cultivation on Raji cells.     

Herpesvirus saimiri-immortalized human lymphocytes: novel hosts for analyzing HIV type 1 in vitro neutralization

Herpesvirus saimiri-immortalized CD4(+) T lymphocytes (HVS T cells) are activated memory cells that support efficient replication of primary R5 strains of HIV-1, which predominate in virus transmission. Being continuous, they are phenotypically more stable and technically less demanding than peripheral blood mononuclear cells (PBMCs). Here we present the first report using HVS T cells to assay HIV-1 neutralization in vitro. Neutralization sensitivities of paired viruses isolated from individuals in both HVS T cells (CN-2 cells) and PBMCs were similar, with homologous and heterologous plasma/sera in both CN-2- and PBMC-based assays. Analysis of V3 loop and CD4-binding site (CD4-BS) sequences showed that changes present in CN-2 isolates were neither more numerous nor more significant than those selected in their PBMC counterparts. Neutralization profiles of CN-2/PBMC virus pairs were similar again when V3- and CD4-binding site (BS)-specific monoclonal antibodies, whose mapped epitopes were conserved or of similar sequence in the virus pairs, were tested. Unlike other T cell line isolates, CN-2 isolates were not more sensitive to neutralization than their PBMC counterparts. We also show that HVS T cells do not appear to exert significant biological selection pressures on primary isolates. Paired viruses have a similar phenotype with respect to syncytium formation, cell tropism, and coreceptor usage. Thus CN-2 cells are suitable hosts for assaying neutralization and could be useful in standardizing neutralization assays performed in different laboratories.     

Immunological responses to envelope glycoprotein 120 from subtypes of human immunodeficiency virus type 1.

The outer envelope glycoprotein (gp120) from subtypes A-E of HIV-1 was purified using a specific high mannose-binding lectin, Galanthus nivalis agglutinin. All isolates were grown in peripheral blood lymphocyte cells in order to avoid selection in cell lines. A comparison of the reactivities of the envelope proteins was made using sera from patients infected with the different subtypes. In this study, the B and C subtype envelope glycoproteins showed the strongest immunological reactivity, when reacted with sera from patients infected with the same subtype of virus. On the other hand, sera of patients infected with subtype A or C virus had the strongest and broadest reactivities, to envelope glycoproteins of many subtypes. The purified gp120 proteins from all five subtypes stimulated mononuclear cells from HIV-1 (subtype B)-infected patients, indicating conserved T cell-activating epitopes. The immunological reactivities indicate that strong antigenicity does not always predict the broadest immunogenicity of an envelope glycoprotein. Glycoprotein 120 from foreign subtypes may serve to induce strong cross-reactive immune responses.     

A new transmissible viral hepatitis of marmosets and tamarins

Callitrichid hepatitis (CH) is a newly recognized, acute, fatal, epizootic disease of New World primates in the family Callitrichidae. Since 1980, 12 outbreaks of CH have occurred in US zoos, involving several callitrichid species including the endangered golden lion tamarin (Leontopithecus rosalia). CH was experimentally transmitted to common marmosets via a bacteria-free filtrate of liver from a naturally infected tamarin. All three inoculated marmosets developed an acute fatal disease with the characteristic clinical and histopathologic findings of CH. Human hepatotropic viruses that can infect the livers of callitrichids were not detected serologically in any of the experimentally infected marmosets. Enveloped viruslike particles 85-105 nm in diameter were observed in the rough endoplasmic reticulum and Golgi complex of hepatocytes from both naturally infected and experimentally inoculated animals. An immunoblot assay was developed using sera from tamarins exposed to natural outbreaks of CH and liver extracts from experimentally infected or control marmosets. A new CH-specific antigen was detected in the livers of naturally infected and experimentally inoculated marmosets but not controls. These results suggest that the etiologic agent of callitrichid hepatitis is a new primate hepatitis virus.     

Arbovirus infection in humans in NSW: Seroprevalence and pathogenicity of certain Australian bunyaviruses

A sero epidemiological study was carried out on human sera from all regions of New South Wales for the presence of antibodies to nine bunyaviruses viz Aino, Akabane, Belmont, Gan Gan, Kowanyama, Mapputta, Peaton, Tinaroo, Trubanaman and the orbivirus Corriparta. Neutralising antibodies were found in titres up to 1280 to Gan Gan and to 640 to Trubanaman viruses, prevalences 4.7% and 1.4% respectively. Neutralisation titres up to 40 were found to Belmont, Aino, Peaton and Corriparta viruses but the significance of these is uncertain since they may represent either non-specific inhibitors or cross reacting antibodies to related but currently unknown viruses. No antibodies were found to Akabane, Kowanyama, Mapputta or Tinaroo viruses in New South Wales sera. Gan Gan virus appeared to be pathogenic for man being associated with an acute epidemic polyarthritic like illness. Trubanaman virus is suspected of being pathogenic. This is the first report of the pathogenicity of these Australian bunyaviruses.     

Viruses isolated from Aedeomyia squamipennis mosquitoes collected in Panama, Ecuador, and Argentina: establishment of the Gamboa serogroup

Twenty-four virus strains were isolated from Aedeomyia squamipennis mosquitoes collected in Ecuador. One additional strain each was isolated from this species from Panama and ARgentina. All 26 isolates were shown to be related serologically to prototype Gamboa virus, originally isolated from Ad. squamipennis mosquitoes collected in Panama. Antigenic comparisons of eight strains, including prototype Gamboa virus, indicated the existence of four distinct viruses. Neutralization tests with sera from a variety of mammalian and avian species from Argentina provided further evidence that Gamboa serogroup viruses are transmitted between Ad. squamipennis and birds.     

Biological characterization and chemokine receptor usage of HIV type 1 isolates prevalent in Brazil

The human immunodeficiency virus type 1 (HIV-1), the etiological agent of the acquired immunodeficiency syndrome (AIDS), shows a variety of biological properties, which may constitute an obstacle to development of effective vaccines or antiretroviral therapy. To characterize Brazilian strains of HIV-1, we studied 24 viruses isolated from blood samples of HIV-1-positive patients from different regions of the country. To examine the cell tropism and the virus ability to form syncytia, primary macrophages and the CD4+ T cell line MT-2 were infected with these viruses. We found that 22 isolates replicated well in macrophages (macrophage-tropic isolates), 2 infected only MT-2 cells (T cell line tropic variants), while 6 of them grew in both cells. We found 8 syncytium-inducing (SI) and 16 non-SI (NSI) isolates. Continuous cultures of 18 isolates were established in the CCR5+/CXCR4+ cell line PM-1, and SI/NSI features of these viruses were confirmed by cell fusion assay with uninfected CD4+ T cell lines (PM-1, MT-2, H9, and SUP-T1). The coreceptor usage of 18 isolates was investigated by infecting U87 cells transfected with CD4 and chemokine receptors, and we found that 11 isolates infected only CCR5+ cells, 3 only CXCR4+ cells, whereas 4 used both coreceptors. We also observed that X4 isolates were more sensitive to neutralization by dextran sulfate than R5 or R5X4 viruses. Our findings show that the Brazilian isolates are phenotypically similar to those prevalent in other regions, which could mean that therapeutic strategies based on HIV-1 phenotypic properties would be efficient in Brazil, as in other countries.