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1.
为了解2006年广州地区流行的乙型流感病毒株血凝素(HA)和神经氨酸酶(NA)的基因特性,选择病原学监测病毒株和暴发性疫情病毒株,提取病毒RNA并逆转录为cDNA,通过PCR方法扩增乙型流感病毒HA和NA全长基因,将扩增的DNA片段接入T-A克隆载体进行测序,并使用DNAStar软件对测序结果进行分析。结果显示:不同来源的流感病毒株HA的同源性为99%以上,都属于Victoria系;不同来源的病毒株NA同源性为98%以上。HA和NA的种系发生树分析表明:病原学监测毒株同源性更接近,而暴发性疫情毒株的同源性则相对较为分散。所有毒株与WHO推荐的2005~2006年度疫苗株B/Shanghai/361/2002的同源性只有88.9%~89.7%,说明该年度的流感疫苗对乙型流感不能提供最佳的保护。  相似文献   

2.
测定7 例慢性 H B V 携带者 H B V 基因组全序列,经同源性比较,确定基因型。2 例基因型为 B 型,余均为 C 型;血清型adr 4 例,adw 3 例。各序列间 X 基因差异最大。未见 A1896 、 T1762 A1764等重要位点的变异。结合已有的2 株 H B V 中国流行株全基因序列,初步建立以中国流行株序列为基础的 H B V 标准序列,该标准序列与国外标准序列仅有22 个位点的差异  相似文献   

3.
为了解我国不同地区呼吸道合胞病毒(RSV)感染特征是否与基因变异有关,对北京、广州、长春和河北四个地区不同流行特征中分离的RSV毒株的G蛋白基因进行了序列分析。结果表明,该G蛋白基因同国外A型亚原型株(A2株)间存在显著差异,A2株同分离株间的核苷酸同源性为92.7-93.6%,氨基酸同源性只有88.3-89.9%。分离株间的核苷酸同湃性为96.0-98.9%,氨基酸同源性92.6-97.7%。氨  相似文献   

4.
用HSV-1接种人单核细胞传代株U_(937)和T淋巴细胞传代株HSB_2细胞,通过对病毒滴度、细胞增殖与病变、病毒抗原表达及病毒DNA的动态观察,研究了HSV-1感染两种细胞的特点。结果发现接种病毒后,U(937)细胞仅允许病毒短时间低滴度复制,培养上清中病毒滴度在12天内降至测不出水平,细胞经过1~2周后增殖受抑、死亡增多,然后又逐渐恢复;用LPS持续刺激则能提高病毒感染滴度,延长感染时间,形成短期持续感染。HSB_2细胞允许病毒复制至较高滴度,呈现急性杀细胞性感染;用PHA持续刺激也不改变细胞感染的特点。  相似文献   

5.
利用呼吸道合胞病毒的单克隆抗体,通过间接免疫荧光法和免疫转印法对本室分离到的武汉地区1988-1992年的56份RSV毒株进行了分型,可将其分为A、B两型和B1、B2亚型,流行病学分析显示:本地区RSV的主要流行株,四年中有三年为B型株。不同于欧美等地;A、B两型的分布还具有灶化分布的特点;两型在性别、发病年龄之间无显著性差异。  相似文献   

6.
1989~1994年中国发生的脊髓灰质炎流行,疫情开始集中于华东、中南地区,后期趋于南部沿海一带。对近百份来自18个省、市、自治区脊灰病毒流行期间标本的分子生物学特征分析,发现流行主要由脊灰病毒Ⅰ型野毒株引起,未发现Ⅱ型野毒株,但1993年在新疆分离到1株Ⅲ型野毒株。Ⅰ型野毒株中共存在4个基因型病毒,其中CHNP1-R91型病毒为这几年流行中新产生的重组病毒,在VP1/2A区含有一段疫苗株序列,另一段野毒株序列很可能来自CHNP1-JX89型病毒。这两个基因型病毒分布在全国大部份地区。病毒核酸的亲缘关系研究还证明,92~94年流行在南方沿海一带的脊髓灰质炎,主要由91年产生的重组病毒引起。此研究揭示了各地区、各基因型病毒与疫情之间的流行病学关系及传播模式。  相似文献   

7.
为从全基因组水平研究乙型肝炎病毒(HBV)的核苷酸结构及复制和抗原表达特性,分别从2例HBsAg和HBeAg阳性、HBV DNA滴度为10^14和10^13拷贝/ml的慢性乙型肝炎患者(编号为56和2-18)血清中扩增、克隆了HBV全基因组,并测定了核苷酸序列。两株病毒基因组转染HepG2细胞的培养上清中HBsAg水平基本相同,但#56毒株表达的HBeAg约为#2-18株的3倍,Southerm印  相似文献   

8.
利用逆转录套式PCR扩增Ⅲ型中国株HCVE2/NS1基因片段,将其克隆到pcDNA3载体上.采用双脱氧链终止法测定插入片段的核苷酸序列.并与已知分离株的相应区域进行同源性比较.首次克隆出Ⅲ型中国株HCVE2/NS1基因(HC-W14),其核苷酸序列与Ⅲ型日本株HCV(HC-J6)该区域同源性为88.37%,其推定的氨基酸同源性为89.29%.而与已知的非Ⅲ型株HCV该区域相比,核苷酸及氨基酸的同源性均相对较低.Ⅲ型中国株HCV与Ⅱ型中国株HCV在E2/NS1区域有较大的变异,揭示研制我国的HCV疫苗应该考虑这种基因型之间的变异性.  相似文献   

9.
从人AFP免疫小鼠脾细胞mRNA中扩增出全套抗体V区基因并随机拼接为ScFv基因,构建全套ScFv基因噬菌体呈现文库,经两轮panning筛选富集,一次从94个单个重组噬菌体克隆中筛选到14个具有AFP结合活性的克隆,测定两个阳性克隆中ScFv基因的核苷酸序列,获得一个V_H基因和两个V_K基因,其基因序列分别与鼠IgV_HJ558、V_k-OX1和V_k4/5家族同源性最高;推导出的氨基酸序列中均含有抗体V区特征性的两个恒定的半胱氨酸残基、具有明确的三个CDR和四个FR序列,表明这三个基因均系新发现的功能性鼠抗体V区基因序列。  相似文献   

10.
我国河南与北京腹泻患儿中的星状病毒感染   总被引:4,自引:0,他引:4  
人星状病毒(HAstV)是RNA病毒的新家族,从我国河南和北京两地区的急性腹泻患儿便样中鉴定了7株星状病毒,经电镜观察病毒颗粒直径约为28nm,表面呈五角或六角星状形态,用RT-PCR检定为阳性,比较PCR扩增产物的核苷酸序列构建的序列同源性树表明,1990年在河南流行的星状病毒主要为HAstV-1,另有一株HAstV-5,1996年北京流行株为HAstV-5。对HAstV患儿的临床症状进行了讨论  相似文献   

11.
The unexpectedly low efficacy of influenza vaccine during school outbreaks of influenza B virus in the spring of 1987 in Japan was probably attributable to a poor antibody response of vaccinees to the epidemic viruses. An antigenic analysis of the causative B viruses isolated in 1987 and 1988 showed much variation in hemagglutination inhibition patterns. The nucleotide sequences that code for the HA1 domain of B/Fukuoka/c-27/81, B/Ibaraki/2/85, B/Nagasaki/1/87, and B/Yamagata/16/88 viruses were determined and compared with those of the previously reported hemagglutinin genes. The nucleotide sequences of the hemagglutinin gene of a new variant, B/Yamagata/16/88, had only 93.4% homology with those of two other viruses from the same epidemic. An analysis of nucleotide and amino acid substitutions of the hemagglutinin genes of influenza B viruses revealed that new and some old variants could cocirculate in the same epidemic. A phylogenetic tree constructed by the neighbor-joining method allowed estimation of an evolutionary rate of 2.3 x 10(-3) synonymous (silent) substitutions per nucleotide site per year in the hemagglutinin gene.  相似文献   

12.
采用常规的血清学收验和特异性RT-PCR方法对华东地区家养水禽中流感病毒的带毒状况进行两年多的监测,分离鉴定出多株H6亚型禽流感病毒。对其中的一株A/Duck/Yangzhou/233/02(H6N2)(简称DkYZ23302)(H6N2)的表面膜蛋白基因进行了序列测定,并与GenBank中收录的其它序列进行了比较,遗传进化结果表明DkYZ23302的血凝素基因(HA)与近年香港分离的鸭源毒株DkHK346199(H6N1)、中国台湾鸡源毒株CkTaiwanna398的亲缘关系最近;而神经氨酸酶基因(NA)遗传进化分析结果表明DkYZ23302(H6N2)的NA基因起源于禽源H9N2亚型流感病毒,这可能是不同亚型禽流感病毒在水禽体内发生基因重配的结果。DkYZ23302(H6N2)的HA推导的氨基酸剪切位点序列为P-Q-I-E-T-R-D,为典型低致病性禽流感病毒的特征序列,与对SPF鸡的致病力试验相吻合。  相似文献   

13.
从广东省疑似流感发病猪分离到1株H3N2亚型猪流感病毒(A/Swine/Guangdong/01/2005(H3N2)),对其各个基因进行克隆与测序,并与GenBank中收录的其它猪流感、禽流感和人流感的相关基因进行比较,结果表明,HA全基因与广东2003~2004年分离的H3N2猪流感毒株的核苷酸序列同源性在99%以上,与纽约90年代末分离的H3N2人流感毒株同源性在98.5%以上;NA基因与纽约1998~2000年分离的H3N2人流感毒株的核苷酸序列同源性在99%以上;NS基因、M基因的核苷酸序列与H1N1亚型猪流感毒株A/swine/HongKong/273/1994(H1N1)的核苷酸序列同源性较高,分别为97.9%、98.4%,与美洲A/swine/Iowa/17672/1988(H1N1)的核苷酸序列同源性分别为96.7%、97.1%;其他基因的核苷酸序列与H3N2人流感毒株具有很高的同源性。因此,推测其M和NS基因来源于H1N1亚型猪流感病毒,HA、NA及其他基因均来源于H3N2亚型人流感病毒。表明此H3N2亚型猪流感病毒为H3N2亚型人流感病毒和H1N1亚型猪流感病毒经基因重排而得到的重组病毒。  相似文献   

14.
The community surveillance of respiratory virus infections performed during 1985-1987 in Sendai and 1988-1990 in Yamagata has identified a total of five herald waves of influenza virus infections: A/H3N2 virus infections in 1985 and 1989, A/H1N1 virus infections in 1986 and 1988, and type B virus infections in 1989. To investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza A/H1N1 viruses isolated during the 1986 and 1988 herald waves were compared with those isolated during the 1986-1987 and 1988-1989 epidemic seasons, respectively, utilizing hemagglutination inhibition tests with anti-hemagglutinin monoclonal antibodies and oligonucleotide mapping of total viral RNAs. The results showed that multiple variants differing in antigenic and genetic properties were cocirculating during the 1986 herald wave as well as during each of the two epidemics (only one strain was isolated in the 1988 herald wave). It was also observed that viruses which had the antigenic and/or genetic characteristics closely similar to those of the viruses circulating in the 1986 and 1988 herald waves, were isolated during the winters of 1986-1987 and 1988-1989, respectively.  相似文献   

15.
Pigs are proposed to be “mixing vessel” hosts that can produce genetically novel reassortant viruses with pandemic potential. The appearance of any novel influenza viruses among pigs should pose concerns for human health. Here, we report the complete genome sequence of a novel H4N1 influenza virus [A/Swine/HuBei/06/2009(H4N1)] isolated from a pig in Central China in 2009. The genomic sequence analysis indicates that this virus is a wholly avian-original influenza virus. Each gene may come from different avian influenza viruses outside mainland China, suggesting the role of migratory birds in the dispersal of influenza virus.  相似文献   

16.
Although the important role of the non-structural (NSI and NEP) gene of influenza A in virulence of the virus is well established,our knowledge about the extent of variation in the NS gene pool of influenza A viruses in their natural reservoirs in Kazakhstan is incomplete.17 influenza A viruses of different subtypes were studied in this paper.Seven types of haemagglutinin and five different neuraminidase subtypes in eight combinations were found among the isolated viruses.A comparison of nucleotide sequences of isolated viruses revealed a substantial number of silent mutations,which results in high degree of homology in amino acid sequences.By phylogenetic analysis it was shown that two distinct gene pools,corresponding to both NS allele A with 5 Clades and B,were present at the same time in Kazakhstan.The degree of variation within the alleles was very low.In our study allele A viruses had a maximum of 5% amino acid divergence in Clade while allele B viruses had only 4% amino acid divergence.  相似文献   

17.
鸭源H9N2AIV血凝素基因序列比较   总被引:1,自引:0,他引:1  
为明确国内外鸭源H9N2亚型禽流感病毒(Avian influenza virus,AIV)血凝素基因(hemagglutinin,HA)的遗传进化关系、血凝素蛋白裂解位点的氨基酸结构特征和血凝素蛋白受体结合位点的氨基酸变异特征,本研究选取GenBank中登录鸭源H9N2亚型AIV HA基因,通过MEGA4.1进行比对和分析,并绘制其遗传进化树。结果表明,鸭源H9N2亚型AIV在遗传进化上分为2大谱系:即Ck-Bj-1-94-like和North-Ame-like,中国大陆鸭源H9N2亚型AIV和亚欧美其它国家鸭源H9N2亚型AIV在遗传进化上分居完全不同的谱系,相互之间遗传进化关系较远。从血凝素受体结合位点看,亚欧美国家鸭源H9N2亚型AIV在第183、190和226位点的氨基酸均为鸭源AIV经典H、E和Q,且高度保守。但中国大陆地区H9N2亚型AIV第183位为N;第190位为A or V or T,与中国大陆鸡源H9N2亚型AIV一致;第226位中国鸭源H9N2亚型AIV有相当一部分为L,且近年福建省H9N2亚型AIV分离株在此处均为L。提示我们,中国大陆地区H9N2亚型AIV鸭鸡和鸡鸭相互交叉感染较为普遍。  相似文献   

18.
There has been multiple evidence that domestic poultry may act as a vessel for the generation of novel influenza A viruses. In this study, we have analyzed the evolution and pathogenicity of 4 H5N2 avian influenza viruses isolated from apparently healthy poultry from H5N1 virus endemic areas in China. Phylogenetic analysis revealed that two of these viruses, A/duck/Eastern China/1111/2011 (DK/EC/1111/11) and A/goose/Eastern China/1112/2011 (GS/EC/1112/11) were derived from reassortment events in which clade 2.3.4 highly pathogenic avian influenza (HPAI) H5N1 viruses acquired novel neuraminidase and nonstructural protein genes. Another two isolates, A/chicken/Hebei/1102/2010 (CK/HB/1102/10) and A/duck/Hebei/0908/2009 (DK/HB/0908/09), possess hemagglutinin (HA) gene belong to clade 7 H5 viruses and other genes from endemic H9N2 viruses, or from viruses of various subtypes of the natural gene pool. All of these H5N2 isolates bear characteristic sequences of HPAI virus at the cleavage site of HA, and animal experiments indicated that all of these viruses but DK/HB/0908/09 is highly pathogenic to chickens. In particular, DK/EC/1111/11 and GS/EC/1112/11 are also highly pathogenic to ducks and moderately pathogenic to mice. All of these 4 viruses were able to replicate in domestic ducks and mice without prior adaptation. The emergence of these novel H5N2 viruses adds more evidence for the active evolution of H5 viruses in Asia. The maintenance of the highly pathogenic phenotype of some of these viruses even after reassortment with a new NA subtypes, their ability to replicate and transmit in domestic poultry, and the pathogenicity in the mammalian mouse model, highlight the potential threat posed by these viruses to both veterinary and public health.  相似文献   

19.
2009年3月以来,甲型H1N1病毒已在全球包括中国造成了巨大的危害,所以利用生物信息技术对其进行研究显得十分必要。从NCBI数据库下载中国大陆境内A/swine/H1N1病毒HA基因核酸序列及其编码蛋白序列,利用MEGA4.0软件对核苷酸编码序列构建系统进化树,利用BioEdit软件对蛋白序列进行比对,分析重要抗原位点变异情况,结果显示2010年在广东流行的病毒,从其他地方传播到广东的,而非早期广东流行的的病毒变异而来。2008年福建,山东,北京等地区的病毒传播比较迅速.这些分析结果阐明了中国大陆境内A/swine/H1N1病毒血凝素(HA)基因的进化关系和变异趋向,对于研究A/swine/H1N1病毒具有重要的参考价值。  相似文献   

20.
为从分子水平掌握我国H9亚型AIV的遗传变异情况和流行规律,本研究汇集近年来从我国12个省、市、自治区的发病鸡群中分离到的23株H9亚型禽流感病毒,通过RT-PCR方法和核苷酸序列测定获得了23个毒株的HA基因cDNA核苷酸序列。核苷酸和推导的氨基酸序列同源性比较结果表明,这些毒株HA基因的核苷酸序列同源性为94.1%~100%,氨基酸序列同源性为95.4%~100%;将这23个毒株和来自亚洲及世界其它地区的另外31株的HA基因cDNA序列同源性进行比较发现,分离自香港的HK170499株与日本的2个毒株关系较近;氨基酸序列分析发现,CKGS199、CKTJ196、CKTJ296、CKSH300和CKBJ197五个毒株各发生了一个潜在的糖基化位点的丢失。54株H9亚型AIVHA基因55bp~1152bp的氨基酸序列分析发现,裂解位点尽管有10种基序,但本研究中的23株和近年来从我国大陆和香港地区的分离的毒株则均为RSSR↓GLF;构成受体结合位点的191位氨基酸有一个规律,即所有中国大陆毒株与部分香港毒株都为N,其它毒株均为H,141aa~143aa处的糖基化位点有与191aa类似的规律,即:凡是191aa为N的毒株,该处均为NVS(CKBJ194除外),凡是191aa为H的毒株,则该处均为NVT;遗传发生关系分析,中国大陆毒株处于欧亚谱系的第一支。本研究结果表明近年来我国鸡群中H9N2亚型禽流感病毒的感染流行可能有一个共同的来源,这为制定防治该亚型禽流感流行的有效对策提供了重要的科学依据。  相似文献   

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