人偏肺病毒基因型双重逆转录PCR检测方法的建立

目的 建立一种鉴别不同基因型hMPV的RT-PCR方法.方法 根据不同基因型的hMPV G蛋白基因序列设计合成A、B基因型的特异性引物,在一次双重PCR反应中根据扩增产物大小鉴别不同基因型.用该方法鉴别37份hMPV阳性的临床标本的基因型.结果 用hMPV G蛋白编码基因的分型引物进行PCR反应,对已知的hMPV阳性标本直接进行分型得到的扩增产物大小易于区分;对常见的呼吸道病毒无非特异扩增,显示引物特异性良好.对37份临床标本进行基因分型结果显示,20份A基因型分型结果与M基因测序分型结果一致,17份经M基因测序分型为B基因型的阳性标本中有14份与M基因测序分型结果一致,3份未得到扩增产物从而不能分型,总符合率为91.9%[(20+14)/37].结论 成功建立了一种可以鉴别不同基因型的hMPV的RT-PCR方法.     

P基因片段测序分析HBV基因分型及耐药位点

目的 建立一种高效、准确的HBV基因分型及核苷类药物相关耐药突变位点分析的新方法.方法 2011年7至8月在太原市第三人民医院收集48份乙型肝炎患者血清标本,利用商品化核酸提取试剂盒提取标本DNA,然后分别进行HBV全基因组和P基因片段扩增,最后对产物进行测序分析,通过构建系统发生树和Genotyping软件分析两种方法进行基因分型,并对两种扩增产物的分型结果进行比较.结果 共得到48条HBV全基因组序列,通过构建系统发生树和Genotyping软件分析两种方法确定12条B型序列和36条C型序列;对HBV P基因片段测序产生的序列进行分型,结果与全基因组测序分析完全一致.通过对HBV P基因序列进行分析,共发现7种核苷类药物耐药突变形式,所测标本突变比例达27.1％ (13/48),其中所有突变均与拉米夫定或阿德福韦酯相关,未检测到其他核苷类药物相关耐药突变位点.另外,利用荧光定量PCR法对同样48份标本进行分型检测,共得出B型11例,C型35例,BC混合型2例.结论 乙型肝炎病毒P基因片段测序可能是一种新型乙型肝炎病毒分型方法.同时,该方法还可对核苷类药物相关耐药突变进行分析,为乙型肝炎临床治疗提供依据.     

HBsAg ELISA-/NAT+的HBV血清学模式和病毒变异分析

目的结合乙型肝炎病毒核酸(HBV DNA)的检测结果,分析血清标本血清学模拟及DNA序列,了解HBV DNA以及HBsAg血型模式之间的关系。方法选自该院54例血液标本作为本研究对象;对标本行HBV DNA提取、PCR扩增处理、PCR产物纯化、DNA测序、HBV基因分型和序列分析,并运用生物信息学软件对测序结果进行分析处理,对比分析基因突变情况。结果 PCR扩增结果,54例标本中40例表现为非常显著的PCR扩增不佳,14例标本PCR产物电泳均能够观察到1 400bp特异性条带;22例为HBsAg ELISA阳性,14例为隐匿性HBV阳性,PCR扩增阳性行基因型检测,B型基因在HBsAg ELISA中占81.82%,C型基因在隐匿性HBV阳性中比例为78.57%,差异具有统计学意义(P0.05);14株隐匿性HBV基因中,6例在S区区域内发生基因序列点突变,其中2例在1个碱基点出现突变,另3例在2个位点的碱基点出现突变;3例HBV基因C型感染者出现基因点突变,2例B基因型感染者出现基因点突变;5例标本在9个位点部位的"a"决定族内碱基点出现突变,A-C的突变较多。结论血液筛查中,检测显示为HBsAg的阴性合格血液,仍可能有隐匿性乙肝感染和窗口期漏检,其病毒株主要为C型,且有变异株,B型病毒株相对较少,但突变株相对较高,可能逃避现有筛查试剂。     

不同DNA聚合酶对HBV PCR产物保真度的影响

PCR已广泛用于HBV感染标志物病毒DNA的定量检测~([1]),对PCR产物进行测序可分析HBV基因点突变,如检测拉夫米定等药物治疗诱导的与耐药相关的HBV基因点突变~([2-3]),研究乙型肝炎慢性化与转归的分子机制~([4]),分析基因多位点突变与HBV感染导致的肝细胞癌转移与复发的疾病预后的关系~([5]).PCR在HBV基因多位点突变的检测与研究中起重要作用.     

乙型肝炎病毒基因的巢式聚合酶链反应-限制性片段长度多态性分型及初步应用

目的 用改进的乙型肝炎病毒(HBV)巢式聚合酶链反应—限制性片段长度多态性(PCR—RFLP)的基因分型方法初探广州地区HBV基因型分布状态。方法 设计巢式PCR扩增前S基因，经限制性内切酶AvaⅡ和DpnⅡ酶切鉴别HBV A—G基因型；并对140份乙型肝炎患者血清进行基因分型，其中随机挑选3份进行克隆测序，并对20份患者血清进行巢式PCR—RFLP重复分型试验，以验证此分型技术的稳定性和特异性。同时采用PCR和巢式PCR对92份乙型肝炎病毒e抗原(HBeAg)阴性血清进行HBV DNA阳性率检测比较。结果 基因分型与测序结果一致；基因分型重复试验符合率100％；92份HBeAg阴性血清经PCR和巢式PCR扩增HBV DNA的阳性率分别为20．7％和68．5％。140份乙型肝炎患者血清中HBV基因型以C型(94份)和B型(42份)为主，偶见A型(4份)。结论 巢式PCR—RFLP HBV基因分型方法具有良好的敏感性、特异性、稳定性，且操作简便，适用于临床和流行病学调查研究。     

赣州地区HBV Enh-I/X基因启动子的突变及对肝脏疾病进程的影响

目的通过对HBV Enh-I/X基因启动子序列的测定和比较,探讨其突变与肝脏疾病进展的关系。方法收集125份乙型肝炎感染者的血清标本HBV-DNA,PCR扩增HBV Enh-I/X基因并测序,比较不同患者之间的突变差异。结果获得HBV Enh-I/X基因42份,其中慢性乙型肝炎(CHB)20例,肝硬化(LC)14例,肝细胞癌(HCC)8例。突变率较高的位点有A1077C,A1123T和G1218C/A在CHB、LC及HCC组中的突变率分别为:20%、64.29%和50%;10%、50%和37.5%;50%、42.9%和50%。对CHB、LC和HCC三组患者间进行比较,位点A1077C在LC组和HCC组的变异率为64.29%和50%,显著高于CHB组(20%,χ~2=7.076,P=0.029);位点A1123T在LC组和HCC组的变异率为50%和37.5%,显著高于CHB组(10%,χ~2=7.619,P=0.022);位点A1317G在LC组和HCC组的变异率为35.71%和50%,显著高于CHB组(5%,χ~2=8.019,P=0.018)。结论HBV Enh-I/X基因启动子序列上存在多位点的突变,可能影响转录水平及复制水平,使病情进展趋于复杂,了解其突变情况为乙型肝炎的治疗和控制疾病发展提供病毒学分子信息。     

乙型肝炎病毒YMDD变异与基因分型及临床关系的研究

目的了解青岛市乙型肝炎患者乙型肝炎病毒（HBV）基因变异特征,探讨HBV YMDD变异与基因分型、DNA载量及临床分型的关系。方法应用实时荧光聚合酶链反应（PCR）技术对820例乙肝患者血清进行基因变异检测,HBV DNA定量监测及基因分型检测。结果 820例HBV感染者中检出YMDD变异154例,变异率18.78%;各基因型间YMDD变异的差异有统计学意义,P〈0.05;患者HBeAg阳性与否与YMDD变异差异有统计学意义（P〈0.05）,HBeAg阳性者更易发生变异;HBV感染者临床分型各组间YMDD变异的差异有统计学意义（P〈0.05）,其中以LC（36/113）、CHB（97/368）为主;病毒变异在性别、年龄及DNA载量各组间的差异均无统计学意义（P〉0.05）。结论 HBV YMDD变异的监测对乙肝患者的治疗、病情预测和转归都有重要临床意义。     

建立一种PCR产物直接测序检测HBVYMDD突变的方法

目的 建立检测HBV YMDD变异的PCR产物直接测序法,并与传统实时荧光PCR检测YMDD突变的结果进行比较分析.方法 选取103份慢性乙型肝炎患者血清标本,提取血清HBVDNA.用实时荧光PCR检测YMDD突变;用巢式pcR扩增HBV逆转录酶基因,对PCR产物进行DNA双向测序,NTI软件比对结果.采用Kappa一致性检验对DNA测序法检测的rt204位点突变与实时荧光PCR检测的YMDD突变结果进行比较.结果 PCR产物直接测序法可有效检测低病毒载量标本(500拷贝/ml)和高病毒载量(1010拷贝/ml)标本,同时可以避免高病毒载量标本的抑制效应.与实时荧光PCR相比较,YIDD突变检测符合率为100%,YVDD突变检测符合率97.1%,YIDD与YVDD共生突变符合率76.2%(Kappa=0.853,P<0.01).结论 本研究建立的PCR产物直接测序法检测HBV耐药相关基因突变,灵敏度高,检测范围宽,与实时荧光PCR检测结果有较高的符合率,并可同时检出YMDD、YIDD和YVDD.     

MN血型的高分辨率熔解曲线基因分型——附1例罕见Mc血型的鉴定

目的建立MN血型高分辨率熔解曲线(HRM)基因分型方法,进行MN血型基因分型,并探讨罕见Mc血型的鉴定方法。方法收集2013年1月—6月澳大利亚红十字血液服务中心献血者全血标本150例,提取基因组DNA,并利用HRM基因分型方法对MN血型进行基因分型;对HRM分型结果中出现的变异曲线标本,采用直接测序法对GYPA基因外显子2进行测序分析,确证其基因型;同时,利用单克隆抗-M及抗-N通过血清学方法检测待检标本的表型。结果 150例标本中有149例标本的HRM基因分型结果与表型一致;只有1例标本的熔解曲线形态与3个对照标本均不同,提示在扩增片段存在变异位点,血清学结果显示该标本表型为M+N-;但是,该标本的GYPA基因外显子2测序结果显示其在M抗原的1个特异性SNP位点中存在杂合突变:c.71_72GTAG,p.Gly5Glu,根据该结果判断其基因型为MMc。结论 HRM基因分型方法能对MN抗原进行准确分型。Mc是介于M与N抗原之间的1种抗原,能与大多数抗-M及少数抗-N反应,因此,仅利用1种抗-M和抗-N试剂容易导致Mc抗原的漏检,基因分型方法更容易发现Mc血型。     

PCR扩增产物磁珠纯化法应用于HLA测序分型的研究

目的 探讨PCR扩增产物磁珠纯化法应用于HLA测序分型的可能性.方法 采用本实验室建立的HLA-C基因测序分型方法 中的PCR扩增、测序反应和测序纯化等步骤,对96份标本特异性扩增HLA-C基因外显子1～4目的 序列片段约为2 000 bp,扩增产物分别采用OMEGA公司(瑞士)磁珠纯化法及USB公司(美国)的外切酶I...     

乙型肝炎病毒特异性CTL表位变异分析

目的初步调查乙型肝炎病毒(HBV)特异性CTL表位的序列特点,同时探讨乙型肝炎重症化和慢性化的可能机理。方法本研究采用PCR扩增法获取HBV全基因并测序,参考国外文献报道的17个热点HBV特异性CTL表位氨基酸序列,分析其与本文获得的CTL表位氨基酸序列的差别。对患者各个表位变异的差异进行卡方检验。结果获得46份HBV全基因组序列,急性乙型肝炎(AHB)15例,慢性乙型肝炎(CHB)18例,慢性重型乙型肝炎(CSHB)13例。其中40份属于B基因型,6份属于C基因型。对17个表位进行分析发现,B基因型中变异较大的表位有S183-191,S382-390,C18-27,X36-44,X52-60和X115-123;C基因型中有P816-824,C18-27,X36-44,X52-60和X115-123。P816-824表位在CHB和CSHB组的变异率为27.8%和46.2%,显著高于AHB组(0%,P0.01);C23-31表位在CHB组的变异率为22.2%,显著高于AHB和CSHB组(0%,0%,P0.05)。结论了解HBV CTL表位序列特点,分析其与文献报道的CTL表位的差异情况,对防治乙型肝炎的重症化和慢性化具有指导意义。     

原发性肝细胞癌患者肝组织中乙型肝炎病毒X基因的变异

目的:对原发性肝细胞癌(hepatocellular carcinoma,HCC)患者肝组织中乙型肝炎病毒(hepatitis Bvirus,HBV)X基因及其常见变异位点进行检测分析,以探讨HBVX基因及其变异与HCC发生发展的关系。方法:采用聚合酶链反应(polymerase chain reaction,PCR)方法检测22例乙型肝炎表面抗原(hepatitis B surface antigen,HBsAg)阳性的HCC患者肝组织中HBVX基因,并对PCR产物进行基因测序分析,同时检测5例正常肝脏组织中HBVX基因。结果:22例HCC患者癌组织及癌周组织中HBVX基因检出率分别为68%和77%,5例正常肝脏组织中均未检测到HBVX基因,癌组织及癌周组织中HBVX基因检出率均很高(均P<0.0125),而癌组织与癌周组织的阳性率没有明显差异(P>0.0125)。癌组织及癌周组织中HBVX基因发生1762T/1764A双突变率分别为93%和47%,肝癌组织中双突变率要明显高于癌周组织(P<0.05),未发现1762T及1764A单独发生突变。结论:HCC患者肝组织中HBVX基因检出率很高,肝癌组织中发生1...     

G1862T mutation among hepatitis B virus-infected individuals: association with viral genotypes and disease outcome in Kolkata, Eastern India

OBJECTIVE: To study the prevalence of G1862T mutation in hepatitis B virus (HBV) isolates among Eastern Indian patients and its relationship with genotypes, HBeAg status and disease manifestation. METHODS: HBV DNA was isolated from patients, amplified by nested PCR and sequenced directly. RESULTS: Of the 102 patients, 32 were HBeAg positive and 70 HBeAg negative; 55, 24 and 23 isolates were infected with genotypes D, A and C, respectively. G1862T was detected in 18 samples, 15 (83%) of them belonged to genotype A (subgenotype HBV/A1), 3 (17%) to genotype D. This mutation was more frequent in HBeAg-negative than in HBeAg-positive patients (21 vs. 9%), whereas in HBV/A1 it was as common in HBeAg-positive as in HBeAg-negative patients and significantly associated with T1762/A1764 mutation. The mean viral load was lower in patients with G1862T mutation. Furthermore, this mutation was common in various clinical outcomes. CONCLUSION: In our community, G1862T mutation was predominantly found in HBV/A1 isolates irrespective of HBeAg status. Moreover this mutation could not be correlated to the clinical outcome. These findings indicate that the G1862T mutation is probably a part of the natural variability of HBV/A1.     

Nucleotide sequence of the precore/core gene and X gene of hepatitis B virus DNA in asymptomatic hepatitis B virus carriers who are negative for serum hepatitis B core antibody

A hepatitis B virus (HBV) carrier who is positive for hepatitis B surface (HBs) antigen but negative for hepatitis B core (HBc) antibody despite persistent HBV infection, is designated as having hepatitis B virus 2 (HBV2). HBV2 is reported to be induced by mild-grade hepatitis. Patients with HBV2 have been reported in Taiwan and Senegal. In the present study, we determined the nucleotide (nt) sequence of the precore/core gene coding region and X gene region of the HBV DNA sequence in 7 subjects who were positive for HBs antigen and negative for HBc antibody. HBV DNA was detected by nested polymerase chain reaction (PCR). Nested PCR was carried out to amplify the precore/core and X open reading frames (ORFs) of HBV DNA. The second PCR products were sequenced, followed by investigation of nt homology. There were no deletions nor insertions in the nt sequence of the precore/core and X ORFs in the HBV DNA of these 7 patients, and mutations were found only sporadically in the 7 patients. Also, there were no common amino acid substitutions in the examined regions of the amino acid sequence of HBV in the 7 patients, and we could not find a common mutation in the examined regions of HBV DNA that could potentially contribute to the development of negativity for HBc antibody. Thus, it is suggested that negativity for HBc antibody in patients with HBV2 is due to an immune response abnormality in the host.     

青岛地区无偿献血者乙型肝炎病毒感染血清学和病毒特征分析

目的 分析青岛地区无偿献血者乙型肝炎病毒感染的血清学及病毒学特征.方法 采用常规的血清学试验和核酸扩增技术对本地区315 520份无偿献血者标本进行联合筛查,对HBsAg-/HBV DNA+标本进行高精度病毒载量检测和补充乙肝5项检测,采用PCR直接测序法获得标本中HBsAg编码基因即S基因序列,分析病毒基因型别及氨基...     

乙肝病毒E抗原和抗体双阳性者中病毒X及前C基因变异热点研究

目的：了解乙型肝炎患者HBeAg和HBeAb双阳性状态下X区及前C区基因热点变异情况，探讨T1762与T1764及A1896热点变异与HBe转换时相的关系。方法：采用时间分辨荧光免疫分析方法定量检测乙肝5项标志物，对HBeAg/HBeAb双阳性标本采用巢式聚合酶链反应扩增，其包括X区及前C区在内的DNA片段，并对阳性的PCR产物直接标记测序，测序结果和Genbank中登录的标准序列相比较。结果：对15例HBeAg和HBeAb双阳性患者血清中HBV DNA进行了检测，阳性11例，测序结果显示，11例HBV DNA阳性者均存在T1762和A1764的突变，但仅有4例患者出现了A1896的突变。结论：在乙型肝炎HBe转换过程中均伴有BCP区T1762和A1764的突变，部分存在A1896位点的突变，T1762和A1764的突变要早于A1896的突变，而A1896的突变主要在E抗体产生过程中或产生以后。     

山西地区61例乙型肝炎病毒耐药变异与基因型检测研究分析

目的通过对山西省乙型肝炎病毒（hepatitis B virus,HBV）P区基因测序的研究,探讨HBV基因变异位点及基因分型的分布规律。方法采集61例HBV患者血清标本,采用双脱氧末端终止法对待检标本P区进行基因序列检测,用Chromas 2．23软件对测序结果进行分析,通过在NCBI网站进行序列比对,并进行基因分型。结果53例受检患者均检测出P区的碱基以及氨基酸序列图,其中,有28例（52．8％）发生突变,突变位点分别有rt204、rt180、rt236、rt173、rt181、n214、rt250、rt213、rt184、rt237;各突变的位点中,以rt204和rt180位点的突变比例最高,分别占67．9％和53．5％。2例为B基因型,阳性率为3．8％,其余51例均为C基因型,阳性率为96.2％。结论山西省地区HBV分布以C基因型多见;发生变异的HBV病毒株中,10个变异位点均有涉及,但是仍以rt204位点突变为主,伴随其他位点突变,提示rt204位点可能存在顺式作用元件,在HBVDNA基因转录、翻译中起到调控作用。     

Nucleic acid sequence analysis of basal core promoter/precore/core region of hepatitis B virus isolated from chronic carriers of the virus from Kolkata, eastern India: low frequency of mutation in the precore region

OBJECTIVE: The aim of the present study was to characterize the predominant hepatitis B virus (HBV) strains and their molecular variants present in the HBV isolates of the different genotypes found among the chronic carriers of the virus in our community. METHODS: Precore/core and core promoter regions of HBV DNA were amplified by polymerase chain reaction and then subjected to direct sequencing. Of the 64 hepatitis B surface antigen (HBsAg)-positive chronic HBV carriers investigated, 44 were HBeAg negative and 20 were HBeAg positive. RESULTS: In addition to genotype D, which was the predominant genotype, 12 genotype C (18.7%) and 6 genotype A (9.4%) were also detected. Presence of T at nt 1858 has often been related to the development of precore stop mutation at nt 1896, while that of C has been related to the development of 1762-1764 double mutation. In our study group, 39 of the 44 HBeAg-negative samples have T1858. The precore stop codon mutation was found in only 8 (18%) of the HBeAg-negative samples. More than half of the HBeAg-negative samples had wild-type sequence in the precore region. The core promoter region could be sequenced from 40 samples, and 1762-1764 double mutation was detected in 13 (32.5%) of them. No significant changes could be detected in the core amino acid sequence of these isolates. CONCLUSION: The pattern of core promoter and precore mutation of HBV isolates in the present study is atypical and not in accordance with reports from other parts of the world, where genotype D and genotype C with T at codon 1858 are common.     

Variations in codons 84-101 in the core nucleotide sequence correlate with hepatocellular injury in chronic hepatitis B virus infection.

Individuals with chronic hepatitis B virus (HBV) infection are generally divided into asymptomatic healthy carriers and patients with chronic liver disease. Several studies have suggested that the hepatitis B core antigen could be an immunological target of cytotoxic T lymphocytes (CTL). To investigate the possible pressure site from CTL, the entire core region of HBV DNA was sequenced in 30 subjects (10 asymptomatic healthy carriers and 20 patients with chronic liver disease). No significant changes in the nucleotide sequence and deduced amino acid residue were noted in the 10 healthy carriers. In contrast, a cluster of changes in a small segment of 18 amino acids (codons 84-101 from the start of the core gene) was found in 15 of the 20 chronic liver disease patients. All these 15 patients had advanced liver diseases (chronic active hepatitis and cirrhosis), whereas only mild liver disease (chronic persistent hepatitis) was found in the five patients without mutations. These data suggest that the region with mutation clustering is the major target of CTL, and that the mutations evolve under the pressure of immune selection.