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1.
为了解HIV抗体阳性血浆中的HIV1病毒基因亚型的情况,应用逆转录PCR和DNA序列测定技术,对6份获自高危人群的抗HIV1阳性血浆进行序列分析和基因亚型分型的研究,结果表明均属HIV1B亚型。V3环氨基酸序列分析指出这些HIV1B亚型病毒株与泰国HIV1B亚型病毒株核苷酸和氨基酸序列相似;同时发现HIV1cDNA和氨基酸序列均相同,推测这6份标本可能来自同时感染同一株HIV病毒的感染者。本研究对了解高危人群中HIV1流行的遗传变异和HIV1亚型病毒株的分子流行病分析具有一定的意义。  相似文献   

2.
陈杰  苏玲中 《病毒学报》1998,14(3):240-245
使用PCR技术对14份广西HIV-1阳性感染者外周血单核细胞(PBMCs)样品进行扩增,获得HIV-1膜蛋白(env)基因的核酸片段,并对其C2-V3及邻区350 ̄450个核苷酸序列进行了测定和分析。结果表明,14份样品中9份为泰国B(B')亚型,5份为E亚型毒株。其中B'亚型毒株的基因离散率为4.2%,与A-E参考亚型及部分B亚型代表株序列相比较,与包括泰国、缅甸及云南德宏在内的B亚型毒株序列十  相似文献   

3.
对来源于我国华东地区的鸡传染性支气管炎病毒流行株QD免疫原S1基因cDNA进行了克隆、序列分析和DNA免疫的初步研究。RTPCR扩增QD毒株的S1基因,将其5′和3′端分别进行分子修饰后插入克隆载体pUC18的BamHⅠ/HindⅢ位点,在大肠杆菌中实现了目的基因的克隆;利用英国IBV毒株S1全基因核酸探针与QD毒株S1基因的重组克隆质粒分子杂交后,采用HaeⅢ,PvuⅡ和XbaⅠ等限制酶对此流行毒株S1基因cDNA进行了酶切分析;在测定QD毒株S1基因5′端高变区核苷酸序列并以此与IBVM41,H120,6/82及Beaud等参考毒株序列对比分析的基础上,构建了QD株S1基因DNA免疫表达质粒,肌肉注射免疫小鼠后,鸡胚病毒中和试验的结果表明,IBVS1基因DNA免疫表达质粒能诱导小鼠产生病毒特异的中和抗体,具有良好的免疫原性,初步显示基因疫苗在鸡传染性支气管炎防治上应用前景。  相似文献   

4.
广西壮族自治区HIV-1流行毒株的基因序列测定和亚型分析   总被引:12,自引:0,他引:12  
使用PCR技术对14份广西HIV-1阳性感染者外周血单核细胞(PBMCs)样品进行扩增,获得HIV-1膜蛋白(env)基因的核酸片段,并对其C2-V3及邻区350-450个核苷酸序列进行了测定和分析。结果表明,14份样品中9份为泰国B(B′)亚型,5份为E亚型毒株。其中B′亚型毒株的基因离散率为4.2%,与A-E参考亚型及部分B亚型代表株序列相比较,与包括泰国、缅甸及云南德宏在内的B亚型毒株序列十分接近,相互之间基因离散率在3.0%-4.4%的范围内;而E亚型毒株的基因离散率为2.1%,与国际E亚型毒株的基因离散率最近,为5.6%,与其它国际参考亚型基因离散率很远,在21.1%-27.3%。根据以上数据及其它资料提示,广西存在B′和E两种亚型的HIV-1的流行,且其B′亚型毒株的传入,与流行在云南德宏州的相同亚型HIV-1毒株密切相关,而E亚型毒株则可能是由泰国经越南传入广西的  相似文献   

5.
以鸡传染性法氏囊病病毒内蒙古毒株(IBDV-NM)dsRNA为模板,用RT-PCR法扩增其主要寄主保护抗原VP2基因的全长cDNA,克隆于pUC19的XbaI/KpnI位点,进行了全序列分析。序列比较发现IBDV-NM毒株VP2基因与已报道的其它7个IBDVCJ801bkf、Cu1、PBG98、52/70、002—73、STC及VariantE毒株之间高度同源,其核苷酸序列的同源率为91.6%~96.2%,推测的氨基酸序列的同源率为96.2%~98.6%。IBDV-NM毒株VP2高变异区的第一个亲水区氨基酸序列与CJ801bkf、Cu1、PBG98、52/70、STC、002—73比较,有一个氨基酸差异,第二个亲水区氨基酸序列与上述6个毒株完全相同。而与VariantE比较,两个亲水区内各有两个氨基酸差异。此外,IBDV-NM毒株VP2具有强毒株所特有的7肽保守区:SWSASGS。这些结果表明,IBDV-NM毒株为标准血清Ⅰ型IBDV强毒株。  相似文献   

6.
根据猪瘟病毒C株的序列,以计算机辅助设计,化学合成1对引物(PF5648/PR6604),应用RTPCR技术从感染猪血中成功地扩增了我国猪瘟病毒强毒石门株NS23基因片段,大小为957bp,位于NS3基因的中部NTPase和Helicase活性区。克隆后测序,结果表明该段基因产物具有解旋酶超家族全部七个特征性保守序列,包括共同的NTP结合基序A位点(GXGKT/S)和B位点(3hy,2x)D。序列同源性比较表明,石门株与日本的ALD和GPE-株同源性最高,与其它3株猪瘟病毒(C株、Brescia株和Alfort株)的同源性也很高,并与2株牛病毒性腹泻病毒(BVDV)(NADL株和SD1株)也有较高的同源性,尤其是由核苷酸序列推导的氨基酸序列,同源性均大于90%,是瘟病毒属基因组中最保守的区段,这与该基因产物在病毒复制及聚蛋白前体加工过程中所具有的重要功能是一致的  相似文献   

7.
汉坦病毒陈株S基因编码区的克隆,序列分析及表达   总被引:1,自引:0,他引:1  
从汉坦病毒陈株感染的VeroE6细胞裂解液中提取病毒RNA,经逆转录PCR获得病毒S基因编码区约1.3kbcDNA片段,克隆该片段后进行核苷酸序列测定,并与汉坦病毒76118株进行同源性比较,结果二者核苷酸序列同源性为86%,推导的氨基酸序列同源性为97%。将该基因片段插入原核表达载体pGEX4T1,在大肠杆菌中获得高效表达。表达产物为GSTNP融合蛋白。SDSPAGE检测表达蛋白分子约72kD左右。Westernbloting和ELISA试验结果表明,表达产物可与多株抗汉坦病毒核蛋白的McAb发生反应,其抗原表位及McAb反应谱与76118株相比存在某些差异。  相似文献   

8.
中国河南株丁型肝炎病毒全基因组的cDNA克隆和序列分析   总被引:3,自引:0,他引:3  
从我国河南-抗丁型肝炎病毒抗原(anti-HDAg)及丁型肝炎病毒(HDv)RNA双阳性的HBsAg携带者血清中提取RNA,采用人工合成的引物进行逆转录和聚合酶链反应(PCR),获得了贯穿HDV全基因组的6个相互重叠的cDNA片段。经双脱氧末端终止法进行核苷酸序列分析,得到了长度为1674bp的我国人河南株HDVcDNA全序列。计算机分析表明,该株与我国台湾株(HDVIA型)、美国-1株(HDVIB型)、日本-1株(HDVⅡ型)和秘鲁-1株(HDVⅢ型)的核苷酸同源性分别为的94.3%、86.8%、75.4%和66.3%,氨基酸序列的同源性分别为89.7%、85.1%、71.9%和64.6%,并在核苷酸和推导的HDAg氨基酸序列中分别发现了5个和2个集中保守的区域。这些区域均与HDV的某些重要功能密切相关。  相似文献   

9.
参考已发表的猪瘟病毒序列,设计并合成了一对引物,应用RTPCR 技术,扩增了猪瘟兔化弱毒(Hog cholera virus lapinized Chinese strain , HCLV) 和石门强毒株的E0 糖蛋白基因,并将其克隆到pGEMT 载体中,测定了其核苷酸序列,并推导了其氨基酸序列。结果表明我国这两株强弱不同毒株E0 糖蛋白核苷酸序列同源性和推导的氨基酸序列同源性分别为95-0 % 和94-3 % ,有13 个氨基酸的差异,HCLV 比石门株多了一个潜在的N糖基化位点。将我国这两株病毒与国外已报导的HCV 毒株E0 基因序列进行了比较,发现石门株与日本的两株毒株ALD 和GPE- 同源性较高,核苷酸序列同源性分别为97-4 % 和96-5 % ,氨基酸同源性分别为97-4 % 和96-0 % ,而与欧洲Brescia 株和Alfort 株同源性较低,核苷酸同源性分别为92-2 % 和86-5 % ,氨基酸同源性为95-2 % 和92-5 % , HCLV 与ALD、GPE- 、Brescia、Alfort 株核苷酸同源性分别为95-6 % 、94-9 % 、91-3 % 、85-5 % …  相似文献   

10.
分别利用5’RACE和3’RACE确定了CMVSDRNA2的5’和3’末端序列,在此基础上,利用RTPCR得到了RNA2的5’端一半的cDNA克隆pC25和3’端一半的cDNA克隆pC23,并通过拼接构建了RNA2全长cDNA克隆pC2F。通过对pC25和pC23进行序列测定,得到了RNA2的全序列。序列分析结果表明CMVSDRNA2由3048nt组成,其中存在2个部分重叠的阅读框ORF1(79~2652nt)和ORF2(2414~2746nt),分别编码858aa的2a蛋白和111aa的2b蛋白,并在2a蛋白的序列中发现了动植物病毒复制酶所特有的两个保守序列。该株系RNA2核苷酸序列与分属CMVI亚组的Fny株系和II亚组的Q株系RNA2的核苷酸序列同源性分别为917%和756%;2a蛋白的氨基酸序列同源性分别为938%和677%,2b蛋白的氨基酸序列同源性分别为830%和513%。同源性比较的结果表明SD株系属于CMVI亚组。  相似文献   

11.
Primary human immunodeficiency virus type 1 (HIV-1) isolates were obtained from 22 patients with AIDS from northern Thailand, where HIV-1 is transmitted primarily through the heterosexual route. Viral sequences were determined for the 22 patients with AIDS, and all were subtype E HIV-1 on the basis of sequence analysis of a region from the envelope protein gp120. Syncytium-inducing (SI) viruses were detected for 16 of 22 patients with AIDS by using MT-2 cells. Characteristics of amino acid sequences in V3 which have not been reported previously for subtype B SI HIV-1 were associated with the subtype E HIV-1 SI phenotype. The SI viruses from our study population contain predominantly a GPGR or GPGH motif at the tip of the V3 loop, in contrast to the previously described subtype E HIV-1 from Thailand which contained predominantly GPGQ. All the SI viruses lost a potential N-linked glycosylation site in V3 which is highly conserved among previously described subtype E HIV-1 isolates from asymptomatic patients from Thailand. HIV-1 envelope sequences including V3 from some patients with AIDS were significantly more divergent than viruses from asymptomatic patients in Thailand characterized 2 years ago or earlier. These results suggest that emergence of subtype E SI HIV-1 variants is associated with the development of AIDS, as it is for subtype B HIV-1. The divergence of subtype E HIV-1 in patients with AIDS as the disease progresses, and the divergence of subtype E HIV-1 in the infected population as the epidemic continues in Thailand, may have important implications for vaccine development.  相似文献   

12.
To clarify the relationship between the amino acid variations of the gp120 of human immunodeficiency virus type 1 (HIV-1) and the chemokine receptors that are used as the second receptor for HIV, we evaluated amino acid site variation of gp120 between the X4 strains (use CXCR4) and the R5 strains (use CCR5) from 21 sequences of subtype B. Our analysis showed that residues 306 and 322 in the V3 loop and residue 440 in the C4 region were associated with usage of the second receptor. The polymorphism at residue 440 is clearly associated with the usage of the second receptor: The amino acid at position 440 was a basic amino acid in the R5 strains, and a nonbasic and smaller amino acid in the X4 strains, while the V3 loop of the X4 strains was more basic than that of the R5 strains. This suggests that residue 440 in the C4 region, which is close to the V3 loop in the three-dimensional structure, is critical in determining which second receptor is used. Analysis of codon frequency suggests that, in almost all cases, the difference at residue 440 between basic amino acids in the R5 strains and nonbasic amino acids in the X4 strains could be due to a single nucleotide change. These findings predict that the evolutionary changes in amino acid residue 440 may be correlated with evolutionary changes in the V3 loop. One possibility is that a change in electric charge at residue 440 compensates for a change in electric charge in the V3 loop. The amino acid polymorphism at position 440 can be useful to predict the cell tropism of a strain of HIV-1 subtype B.  相似文献   

13.
Human immunodeficiency virus type 1 (HIV-1) strains can be separated into genetic subtypes based on phylogenetic analysis of the envelope gene. Once it had been shown that population-wide intrasubtype genetic variation of HIV-1 strains increases in the course of the AIDS epidemic, it remained uncertain whether HIV-1 subtypes are phenotypic entities spreading as distinct virus populations. To examine this, we applied Eigen's concepts of sequence geometry and fitness topography to the analysis of intrasubtype evolution of the gp120 V3 domain of HIV-1 subtypes A, B, C, and D in the course of the global AIDS epidemic. We observed that despite the high evolution rate of HIV-1, the nonsynonymous distances to the subtype consensus of sequences obtained early in the epidemic are similar to those obtained more than 10 years later, in contrast to the synonymous distances, which increased steadily over time. For HIV-1 subtype B, we observed that the evolution rate of the individual sequences is independent of their distance from the subtype B consensus, but for the individual sequences most distant from the consensus evolution away from the consensus is constrained. As a result, individual HIV-1 genomes fluctuate within a sequence space with fixed distance to the subtype consensus. Our findings suggest that the evolution of the V3 domain of HIV-1 subtypes A, B, C, and D is confined to an area in sequence space within a fixed distance to the consensus of a respective subtype. This in turn indicates that each HIV-1 subtype is a distinct viral quasispecies that is well adapted to the present environment, able to maintain its identity in the V3 region over time, and unlikely to merge during progression of the AIDS epidemic.  相似文献   

14.
Comparative nucleotide sequencing was carried out on dengue type 2 virus (DEN-2) strains isolated from patients in Northeast Thailand during the epidemic season in 1993. The patients exhibited different clinical manifestations ranging from dengue fever (DF) to dengue haemorrhagic fever (DHF)/dengue shock syndrome (DSS). The results classified 19 DEN-2 strains into 3 subtypes according to nonsynonymous amino acid replacements. The strain isolated from a DSS patient eliciting secondary serological response belonged to subtype I, whereas 13 strains isolated from DHF patients with secondary response and 2 strains from DF patients with primary response belonged to subtype II. On the other hand, 3 strains isolated from DF cases evoking either primary or secondary response belonged to subtype III. These results suggest that subtype III virus infection could result in clinically milder manifestation irrespective of the serological response compared with subtype I or II viruses. The RNA secondary structure predicted for the 3' noncoding region showed 4 different structures (A, B, C, and D). The result also indicates that different subtypes of DEN-2 serotypes are circulating in a single epidemic in Thailand.  相似文献   

15.
In our study we analyzed the nucleotide sequence of the C- terminal 256 bp fragment of the myfA gene encoding MyfA protein, the major subunit of Yersinia enterocolitica Myf fimbriae. We examined ten representative strains of major Y. enterocolitica pathogenic bioserotypes belonging to European (4/O3; 2/O9; 3/O5,27) and American (1B/O8) phylogenetic lineages. DNA sequencing revealed that consensus nucleotide sequences of the tested myfA fragment were indistinguishable in all the tested strains. The resulting common consensus sequence found in our study was identical to the corresponding fragment of reference sequences Z21953 and NC008800 deposited in GenBank database for pathogenic Y. enterocolitica strains. In contrast, 18 point mutations leading to 13 amino acid substitutions were found when the common consensus sequence was aligned to sequence AY966879 determined for the myfA homologue detected by PCR in Y. enterocolitica 1A strain. The strong conservation of the nucleotide and amino acid sequence of myfA gene among virulent bioserotypes of Y. enterocolitica indicate that fimbriae MyF could play important role in pathogenesis, even before the divergence of European and American lineages.  相似文献   

16.
Functional genes of HIV-1 like the tat express proteins essential for viral survival and propagation. There are variations reported in levels of Tat transactivation among the different subtypes of HIV-1. This study looked at the amino acid differences in the different regions of Tat protein (exon 1) of subtype B and C strains of HIV-1 and tried to observe a molecular basis for protein function. HIV-1 sequences of subtype B (n=30) and C (n=60) strains were downloaded from HIV-1 Los Alamos data base. Among the 60 subtype C strain sequences, 30 each were from India and Africa. A HIV-1 Tat protein (exon 1) sequence, the consensus B and C sequence was obtained from the 'sequence search interface' in the Los Alamos HIV-1 sequence data. The sequences were visualized using Weblogo and the RNA binding regions of the three consensus sequences were also determined using BindN software program. Compared to subtype B, there was a high level of divergence in the auxiliary domain of tat exon 1 (amino acid positions 58- 69). The net charge of the subtype C (Indian) Tat protein (exon 1) auxiliary domain was -1.9 at pH 7 and it had an isoelectric point of 4.1. The net charge of the subtype C (African) auxiliary domain was -2.9 at pH 7 and it had an isoelectric point of 3.7 while the net charge of same region in subtype B was -0.9 at pH 7 with an isoelectric point of 4.9. The ratio of the hydrophilic residues to the total number of residues was 60% in the in both the Indian and African subtype C in the auxiliary domain while this was 50% in subtype B. The consensus subtype B sequence was found to have 36 RNA binding sites while subtype C (India) had 33 and subtype C (Africa) had 32 RNA binding sites. The HIV-1 Tat-TAR interaction is a potential target for inhibitors and being considered for its potential use in HIV-1 vaccines. Development of such inhibitor/vaccines would have to take into consideration the variation in amino acid sequence analyzed in this study as this could determine epitope presentation on MHC class I antigen for afferent immune response.  相似文献   

17.
We set out to analyze the sequence diversity of the Bacillus thuringiensis flagellin (H antigen [Hag]) protein and compare it with H serotype diversity. Some other Bacillus cereus sensu lato species and strains were added for comparison. The internal sequences of the flagellin (hag) alleles from 80 Bacillus thuringiensis strains and 16 strains from the B. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. The flagellin allele nucleotide sequences for 10 additional strains were retrieved from GenBank for a total of 106 Bacillus species and strains used in this study. These included 82 B. thuringiensis strains from 67 H serotypes, 5 B. cereus strains, 3 Bacillus anthracis strains, 3 Bacillus mycoides strains, 11 Bacillus weihenstephanensis strains, 1 Bacillus halodurans strain, and 1 Bacillus subtilis strain. The first 111 and the last 66 amino acids were conserved. They were referred to as the C1 and C2 regions, respectively. The central region, however, was highly variable and is referred to as the V region. Two bootstrapped neighbor-joining trees were generated: a first one from the alignment of the translated amino acid sequences of the amplified internal sequences of the hag alleles and a second one from the alignment of the V region amino acid sequences, respectively. Of the eight clusters revealed in the tree inferred from the entire C1-V-C2 region amino acid sequences, seven were present in corresponding clusters in the tree inferred from the V region amino acid sequences. With regard to B. thuringiensis, in most cases, different serovars had different flagellin amino acid sequences, as might have been expected. Surprisingly, however, some different B. thuringiensis serovars shared identical flagellin amino acid sequences. Likewise, serovars from the same H serotypes were most often found clustered together, with exceptions. Indeed, some serovars from the same H serotype carried flagellins with sufficiently different amino acid sequences as to be located on distant clusters. Species-wise, B. halodurans, B. subtilis, and B. anthracis formed specific branches, whereas the other four species, all in the B. cereus sensu lato group, B. mycoides, B. weihenstephanensis, B. cereus, and B. thuringiensis, did not form four specific clusters as might have been expected. Rather, strains from any of these four species were placed side by side with strains from the other species. In the B. cereus sensu lato group, B. anthracis excepted, the distribution of strains was not species specific.  相似文献   

18.
埃可病毒11型(Echovirus 11,ECHO11)属于肠道病毒B组,是最常见的人类肠道病毒(Human enterovirus,HEV)之一,常引起儿童无菌性脑膜炎、脑炎和急性迟缓性麻痹等疾病。为了对云南省手足口病(Hand,foot,and mouth disease,HFMD)监测中分离到的4株ECHO11毒株的VP1基因进行序列分析,并为云南地区ECHO11的进化及流行趋势等研究提供基础数据,本研究对收集到的HFMD病例标本进行病毒分离培养和鉴定,对鉴定为ECHO11的毒株VP1基因测定其完整序列,与GenBank上其他参考株的VP1区序列构建遗传进化树进行基因分析。结果显示,4株ECHO11型毒株分属A1和D5两个基因亚型,分别与各自基因亚型参考株的同源性为最高。D5基因亚型ECHO11分离株在进化树上聚集为3簇,提示存在多个传播链,其D5-1簇的VP1区氨基酸在多个位点上与同基因亚型的其他簇参考株存在特异突变。本研究揭示,云南地区存在两种不同基因亚型的ECHO11流行情况,特别是D5亚型的出现,提示我国周边流行的ECHO11基因型已进入中国大陆,应密切关注其流行变异情况,为今后制定由ECHO11引起的HFMD的公共卫生策略提供依据。  相似文献   

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