聚合酶链反应-反向杂交快速检测巨细胞病毒糖蛋白gB、gH基因型变异

目的 建立一种简便、快速、敏感和特异的检测巨细胞病毒（HCMV）糖蛋白gB、gH基因型变异的方法。方法 以HCMV糖蛋白基因gH、gBn、gBclv为靶序列，设计17条具有型特异性的寡核苷酸探针，聚合酶链反应(PCR)扩增目的片段，反向杂交检测23例中国和6例德国移植患者HCMVgH、gBn、gBclv基因型变异，其结果与直接测序进行比较。结果 23例中国患者HCMV糖蛋白为gH1和2型，gB1、2和3型，未见gB4型；而6例德国患者的HCMV糖蛋白涵盖gH1和2型，gB1、2、3及4型。中、德国两患者均可同时感染2种不同基因型的病毒株。反向杂交技术对检测患者同时感染不同基因型病毒株优于直接测序。结论 PCR－反向杂交技术具有简便、快速、敏感和特异的特点，适用于临床实验室检测HCMV糖蛋白基因型变异。     

人巨细胞病毒UL149基因在临床低传代分离株中的多态性研究

目的研究人巨细胞病毒(humancytomegalovirus,HCMV)UL149序列在临床低传代分离株中的多态性,探讨HCMV基因多态性与其感染引起不同临床症状之间的关系。方法对29株经荧光定量PCR方法(QPCR)检测HCMVDNA为阳性的临床低传代分离株的细胞培养上清液进行HCMVUL149全序列PCR扩增,并对PCR扩增产物进行序列测定及分析。结果29株临床低传代分离株有26株PCR扩增阳性,与HCMVToledo株进行序列比较分析,26株临床分离株UL149开放阅读框架(openreadingframe,ORF)之间存在着高度的多态性,种系进化树分析结果显示26个序列可分为3个型,黄疸患儿分布以G1型为主;小头畸形以G3型为主;巨结肠仅见于G1、G2型,G3型未见。部分临床分离株存在CKP位点的缺失及TKP位点增加。结论HCMVUL149基因在临床分离株中存在着高度的多态性。来自不同临床症状分离株的UL149基因及其编码蛋白具有一定的结构特点,并与基因型呈一定的相关性。     

乌鲁木齐地区人巨细胞病毒临床分离株PCR-RFLP分析研究

目的 通过对人巨细胞病毒临床分离株基因结构的分析，了解乌鲁木齐地区人巨细胞病毒(HCMV)的分子流行病学情况。方法 分别扩增28株HCMV临床分离株的3个相对保守基因：DNA聚合酶基因(pol)，糖蛋白H基因(gH)和主要即刻早期蛋白基因(MIE)片段并进行限制性片段长度多态性(PCR-RFLP)分析。结果 非流行病学相关毒株限制性图谱差异较大，流行病学相关毒株如母婴配对株限制性图谱有很大的相似性。8对母婴配对HCMV毒株，4对限制性图谱一致，4对存在差异。结论 本地HCMV分离株基因变异广泛存在。PCR-RFLP分析可揭示HCMV感染的传播方式，可用于病毒的分子流行病学研究。     

先天性巨结肠患者人类巨细胞病毒UL139基因多态性的研究

目的研究人巨细胞病毒（HCMV）UL139基因在先天性巨结肠（HD）临床株中的多态性，探讨其多态性与HD之间的关系。方法对53株HD患儿痉挛段肠组织标本和6株尿标本的临床株进行UL139开放阅读框（ORF）的扩增及测序。对照组为10个无症状HCMV感染患儿的尿标本。结果28个HD临床株完成测序，进化树分析结果显示UL139基因DNA序列分为3组5个基因型。G3为主要基因型（48．1％）。与对照组比较，X^2=7．378，P=0．194。24个临床株同时完成了HCMVUL144基因测序，HCMVUL144与UL139基因经Kendall等级相关分析r=-0．114，P=0．425。不同临床分型HD分散分布于UL139各个基因型中。结论HCMVUL139基因具有高度的多态性；UL139基因分型与HD的临床分型无关；UL139基因与UL144基因无相关性。     

先天性巨结肠患者人类巨细胞病毒UL144基因多态性的研究

目的研究人类巨细胞病毒（human cytomegalovirus,HCMV）UL144基因在先天性巨结肠（Hirschsprung＇s disease,HD）临床株中的多态性,探讨HCMV UL144基因多态性与致病性之间的关系.方法随机选取53个先天性巨结肠患儿痉挛段结肠手术标本及经荧光定量PCR方法检测HCMV DNA为阳性的4个HD患儿的尿标本,对照组为无症状或仅有皮肤轻度黄疸的6个尿标本.应用巢式聚合酶链反应的方法,扩增HCMV UL144基因开放阅读框架（ORF）,扩增阳性的临床株进行双向DNA测序,最后通过DNAclub、Bioedit、DNAstar、GeneDoc等软件进行分析.结果23份HD痉挛段肠组织（46%）及4份尿标本HCMV UL144基因扩增阳性,并且完成测序.种系进化树分析结果显示25个HD患儿的DNA序列分为3个基因型,G1A型64.0%,G2型24%,G3型12%.与对照组比较,经χ^2检验,χ^2=10.93,P为0.012;其中HD临床株G1A和G3型基因经Fisher检验,P为0.015,差异具有统计学意义.全结肠型、长段型及普通型HD分散分布于UL144各个基因型中.结论HD与HCMV感染有关,HCMV可能是HD的病因之一;在HD患儿中,HCMV感染以UL144基因G1A型为主;HD的临床分型与HCMV UL144基因分型无关.     

人巨细胞病毒UL138～142基因在临床低传代分离株中的多态性研究

目的　研究人巨细胞病毒 (humancytomegalovirus ,HCMV)UL138～UL14 2基因在临床低传代分离株中的多态性及其与HCMV先天感染致病性之间的关系。方法　对经荧光定量PCR方法检测HCMV DNA为阳性的临床分离株进行UL138～UL14 2基因全序列PCR扩增 ,对扩增阳性的标本进行全序列的测序及结果分析。结果　HCMV临床分离株的UL138、UL14 2ORF(openreadingframe)高度保守 ;UL139ORF呈现高度多态性 ,可被明确划分为 3个基因型 ,且核苷酸及氨基酸的变异主要集中在序列的 5′端 ;所有临床分离株的UL14 0ORF在Toledo株第 174位核苷酸处插入 1个胞嘧啶核苷酸 ,其ORF较Toledo株增加了 2 31个核苷酸 ;所有临床分离株的UL14 1ORF在Toledo株第 2 2 7位核苷酸处缺失了 1个胸腺嘧啶核苷酸 ,故形成UL14 1a及UL14 1b 2个新的ORF。HCMV临床分离株的UL14 0蛋白较Toledo株新增了ScAMP磷酸化和酪蛋白激酶Ⅱ磷酸化位点 ,其它基因编码蛋白的重要功能区域相对保守。结论　HCMV临床分离株UL139ORF的 5′端呈现高度多态性 ,而且被明确地分成 3个基因型 ,故其可能在HCMV先天感染的致病性差异方面起一定作用 ;尚未发现UL138～UL14 2中某个特定基因与HCMV先天感染致病性有本质联系     

HMA-SSCP方法研究人类巨细胞病毒UL144基因在临床低传代分离株中的多态性

目的 探讨人类巨细胞病毒（HCMV）UL144序列在临床患儿低传代分离株中的多态性及与临床疾病的关系。方法 对65株HCMV临床低传代分离株及7例同年龄组HCMV，DNA定量PCR方法检测阳性无症状感染儿尿液进行HCMV-ULl44 PCR扩增及HMA-SSCP分析，并对其中32份阳性标本进行测序。结果 65株分离株中有55株UL144全序列引物PCR扩增阳性，7份QPCR检测HCMV—DNA阳性无症状感染儿尿液中5份UL144全序列引物PCR扩增阳性。60份UL144扩增阳性标本HMA-SSCP（异源双链泳动及单链构象多态分析）呈现3种典型带形，巨结肠患儿分离株序列、小头畸形患儿的序列分布以1型为主，巨结肠患儿分离株序列没有2型，黄疽患儿以3型为主。结论 HCMV-UL144广泛存在于临床低传代分离株中，用HMA-SSCP检测HCMV-UL144基因在临床低传代分离株中的多态性是一种可行的方法。HCMV不同疾病类型的HCMV-UL144序列不同，提示UL144基因可能对HCMV致病性起一定作用。     

巨细胞病毒型别多样性的研究与临床

1 巨细胞病毒的型别多样性及分型方法概述人巨细胞病毒(human cytomegalovirus,HCMV)属于疱疹病毒β亚科,为线状双链DNA病毒,其DNA链全长超过240kb,是最大的疱疹类病毒.虽然HCMV大部分的基因序列高度保守,但部分位点的基因存在不同程度的变异,如编码CXC趋化因子UL146、编码Ⅰ型膜糖蛋白的UL139和编码不同包膜糖蛋白的基因都高度可变.     

人巨细胞病毒UL136基因在临床低传代分离株中多态性分析

目的 研究人巨细胞病毒(human cytomegalovirus，HCMV)UL136基因在临床低传代分离株中的多态性，探讨其多态性与HCMV先天性感染不同致病性之间的关系。方法 对48株经荧光定量PCR方法检测HCMV DNA为阳性的临床低传代分离株进行HCMV ULl36全序列PCR扩增，对于扩增阳性的12株PCR产物进行ULl36基因全序列测定及结果分析。结果 48株临床低传代分离株ULl36 PCR扩增，12株阳性，阳性率25％，以HCMV Toledo株作为参考株，进行序列比较分析表明，12株临床分离株ULl36开放阅读框架(open reading frame，ORF)长度均与Toledo株相同，为723bp，编码241个氨基酸的蛋白。DNA序列变异均为碱基替换，不同临床分离株ULl36基因与Toledo株进行同源性比较，结果在核苷酸水平为97．7％～99．3％，氨基酸水平为96．6％～99．1％。ULl36编码蛋白的氨基酸变异率为0．83％～3．3％。二级结构预测分为两种构象。大多数HCMV ULl36蛋白翻译后修饰位点在所有分离株中均高度保守，仅几个位点在一些分离株中存在缺失或新增。Toledo株及12株临床分离株核苷酸及氨基酸序列系统进化树分析表明：45J最接近Toledo株。结论 12株临床低传代分离株HCMV ULl36基因DNA及其编码产物的氨基酸序列比较保守，但仍存在一定多态性。未发现不同临床分离株ULl36基因多态性与HCMV先天性感染的表现关系。     

人巨细胞病毒UL132基因在先天感染患儿临床株中的变异研究

目的研究人巨细胞病毒(human cytomegalovirus,HCMV)UL132基因序列在先天性感染患儿中的多态性,探讨HCMV基因多态性与其感染引起不同临床症状的关系。方法对30株经荧光定量PCR方法(Q-PCR)检测HCMV DNA为阳性的临床株进行HCMV UL132全序列PCR扩增,并对PCR扩增产物进行序列测定及分析。结果30株HCMV临床株的测序结果与HCMV Toledo株进行序列比较分析显示,临床株UL132开放阅读框架(open reading frame,ORF)间存在着高度的多态性,基因变异主要集中在ULl32 ORF的5’端。30株HCMV临床株种系进化树分析结果显示,UL132序列可分为3个基因型,黄疸患儿分布以G1型为主;神经损伤患儿以G2型为主;巨结肠患儿分别见于G1、G2、G3 3个基因型。所有临床株的ULl32编码蛋白是疏水性蛋白,含有信号肽及跨膜蛋白区域,并在信号肽和跨膜蛋白区域之间存在2个保守的N-糖基化位点。结论HCMV UL132基因在临床株中存在着高度的多态性。来自不同临床症状的HCMV UL132基因及其编码蛋白具有一定的结构特点,提示观132基因及其所编码的蛋白在HCMV的致病性上可能起重要作用。     

Monitoring of human cytomegalovirus glycoprotein B genotypes using real-time quantitative PCR in immunocompromised Chinese patients

Based on sequence variation in the N-terminus of glycoprotein B (gB), human cytomegalovirus (HCMV) can be classified into four gBn genotypes, and these genotypes are associated with different clinical outcomes. The distribution of gBn genotypes and the level of gBn DNA load were examined in immunocompromised Chinese patients using real-time quantitative PCR. In addition, the PCR and pp65 antigenemia results were compared. In 1480 specimens, 81.4% were antigen-positive, 12.6% were PCR-positive. The gB genotype distribution was as follows among PCR-positive samples: gBn1, 63.1%; gBn2, 13.4%; gBn3, 8.6%; gBn4, not detected; mixed genotypes, 14.9% (gBn1 and gBn3, 14.4%; gBn2 and gBn3, 0.5%). The gBn3 and gBn1 genotypes had the highest and lowest copy numbers, respectively (p < 0.05). The quantity of gBn DNA found in PCR-positive, pp65-negative samples was significantly lower than that found in PCR-positive, pp65-positive samples (p < 0.05). The PCR and antigenemia results did not differ among bone marrow transplant patients, solid organ transplant patients, and immunocompromised patients without transplantation (p > 0.05). HCMV gBn genotyping using real-time quantitative PCR was established successfully, and the distribution of gBn genotypes in immunocompromised Chinese patients was investigated. This method may help to understand better the relationship between gBn genotype and clinical outcome and aid in clinical detection.     

Single human cytomegalovirus gB genotype shed in multiple sites at the time of diagnosis in renal transplant recipients

Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in immunocompromised patients, such as renal transplant recipients. Analysis of the gene encoding the envelope glycoprotein B (gB) showed that clinical isolates adopted one of the sequence configurations, permitting the isolates to be assigned a gB genotype of 1-4. It has been suggested that HCMV gB genotypes could be correlated with tropism and pathogenesis. A number of reports in the literature refer to shedding of different gB strains, permitting follow-up of renal transplant recipients. Considering that a single strain might be responsible for the clinical expression of the disease in multiply exposed individuals, the frequency distribution of gB genotypes was examined by nested polymerase chain reaction and restriction fragment length polymorphism in 20 renal transplant recipients at the time of diagnosis. The association between gB genotypes and cellular tropism was determined using blood, saliva, and urine for each patient. HCMV gB genotype 2 was found more frequently than other genotypes (gB2, 40%; gB1, 30%; gB3, 25%; and gB4, 5%) in renal transplant recipients. The gB type did not correlate with tropism for different body sites. All the patients with HCMV infections presumably harbored a single HCMV strain at the time of diagnosis. In multiply exposed patients, the immunomodulation provided by acute HCMV infection could favor later shedding of different strains.     

High prevalence of renal transplant recipients infected with more than one cytomegalovirus glycoprotein B genotype

A prospective analysis of cytomegalovirus (CMV) glycoprotein B (gB) genotypes was conducted on 34 renal transplant recipients using peripheral blood leukocytes (PBLs) and urine specimens. The CMV gB genotypes were analyzed by polymerase chain reaction (PCR) followed by enzyme digestion. PBLs and urine samples showed almost equal proportions of the 4 known gB genotypes, as well as equal proportions of gB genotype mixtures. The gB genotypes 1, 2 and 3 were equally distributed in the patients. Twenty-four (70.6%) patients had more than one gB genotype during follow-up. There was no association of gB genotypes with the development of symptomatic CMV infection.     

Rapid genotyping of cytomegalovirus in dried blood spots by multiplex real-time PCR assays targeting the envelope glycoprotein gB and gH genes

Genotyping of cytomegalovirus (CMV) is useful to examine potential differences in the pathogenicity of strains and to demonstrate coinfection with multiple strains involved in CMV disease in adults and congenitally infected newborns. Studies on genotyping of CMV in dried blood spots (DBS) are rare and have been hampered by the small amount of dried blood available. In this study, two multiplex real-time PCR assays for rapid gB and gH genotyping of CMV in DBS were developed. Validation of the assays with 39 CMV-positive plasma samples of transplant recipients and 21 urine specimens of congenitally infected newborns was successful in genotyping 100% of the samples, with gB1 and gB3 being the most prevalent genotypes. Multiple gB and gH genotypes were detected in 36% and 33% of the plasma samples, respectively. One urine sample from a newborn with symptomatic congenital CMV was positive for gB1 and gB2. DBS of congenitally infected newborns (n = 41) were tested using 9 μl of dried blood, and genotypes were detected in 81% (gB) and 73% (gH) of the samples, with gB3 being the most prevalent genotype. No clear association of specific genotypes with clinical outcome was observed. In conclusion, the CMV gB and gH PCR assays were found to be rapid, sensitive for detecting mixed infections, and suitable for direct usage on DBS. These assays are efficient tools for genotyping of CMV in DBS of congenitally infected newborns.     

Cytomegalovirus glycoprotein B genotype does not correlate with outcomes in liver transplant patients.

BACKGROUND: Based on sequence variation in the UL55 gene that encodes glycoprotein B (gB), human cytomegalovirus (CMV) can be classified into four gB genotypes. Previous studies have suggested there could be an association between CMV gB genotype and clinical outcome in transplant patients. OBJECTIVES: The goal of this study was to determine the distribution of gB genotypes in a cohort of liver transplant recipients with CMV infection and the effect of gB type on clinical outcomes including CMV disease and rejection. STUDY DESIGN: DNA was extracted directly from the blood of 58 liver transplant recipients with CMV infection. The gB genotype of CMV was determined using the polymerase chain reaction to amplify a region of UL55, followed by restriction analysis based on HinfI and RsaI digestion. Results were correlated with CMV viral load, symptomatic disease, and development of acute rejection. RESULTS: The distribution of CMV gB genotypes was: gB1, 15/58 (25.9%); gB2, 16/58 (27.6%); gB3, 21/58 (36.2%); gB4, 2/58 (3.4%) and four patients (6.9%) had mixed infection. No correlation between CMV genotype and peak CMV viral load was observed. Symptomatic CMV disease developed in 25/58 (43.1%) patients and 26/58 (44.8%) had acute rejection. The rate of CMV disease and acute graft rejection in patients infected with the different CMV gB genotypes was not significantly different. However, all four patients with infection with a mixture of CMV gB genotypes developed progression to CMV disease (P=0.030). CONCLUSIONS: The gB genotype did not correlate with peak CMV viral load and with the development of CMV disease or acute rejection following liver transplantation.     

Human cytomegalovirus glycoprotein B genotypes in renal transplant recipients

Based on sequence variation of the glycoprotein B (gB) gene, human cytomegalovirus (HCMV) strains can be classified into four gB genotypes. In a previous study of bone marrow transplant recipients, infection with the gB type 1 correlated with a more favorable clinical outcome than infection with the gB types 2, 3, or 4. The gB type was determined in 60 renal transplant and in 47 bone marrow transplant recipients using PCR and restriction analysis. All HCMV variants in patient specimens could be assigned to one of the four previously described gB types. Two or more specimens obtained from 39 patients were analysed; in 31 of these patients the gB type was the same in all samples. The gB type did not correlate with the clinical outcome or the level of viremia in renal transplant recipients. © 1996 Wiley-Liss, Inc.     

Different human cytomegalovirus glycoprotein B (gB) genotype distribution

The glycoprotein B (gB) is the major glycoprotein of the envelope of the human cytomegalovirus, it is encoded by UL55 open reading frame, implicated in host cell, entry cell to cell virus transmission and fusion of infected cells and a significant is an important target for immuno-reactions humoral and cellular. A prospective analysis of cytomegalovirus glycoprotein B genotype was conducted on 31 immunodepressed (transplant recipients and AIDS patients). The DNA was extracted directly from the bronchoalveolar liquid (BAL) of these patients. The gB genotypes of CMV was determined by using the polymerase chain reaction, followed by the digestion of two enzymes of restriction HinfI and RsaI. The distribution of the gB genotype of the CMV was: gB1 38,70%; gB2 25,80%; gB3 16,12% and gB4 19,35%. The analysis of the peptide sequence of this region (codons 437-520), indicate the variation was more frequent between codons 448-480.     

Cytomegalovirus glycoprotein B genotypes and central nervous system disease in AIDS patients

To investigate any association between cytomegalovirus glycoprotein B (CMV gB) subtypes and central nervous system (CNS) disease in AIDS patients, proportions of different gB genotypes detected in AIDS patients with CNS disease were compared with the gB genotypes detected in AIDS patients with no neurological disorder. The patients were matched by CD4+ cell counts. CMV was detected by PCR in cerebrospinal fluid (CSF) samples obtained from AIDS patients with CNS disease and from urine and saliva samples obtained from AIDS patients without CNS disease. CMV strains obtained were digested by restriction enzymes HinffI and RsaI to classify the genotypes. The CMV gB genotype was determined in 26 CSF samples. Of these, 11/26 (42.3%) typed as gB group 1, seven (26.9%) as gB2, four (15.4%) as gB3, and four (15.4%) as gB4. The CMV gB genotype frequency distribution in the 42 AIDS patients without CNS disease showed that 18/42 (42.8%) were classified as gB group 1, 10 (23.8%) as gB2, seven (16.6%) as gB3, and seven (16.6%) as gB4. In the present study, no association was found between CMV gB genotypes and CMV-related central nervous system disease.     

Concurrent genotyping and quantitation of cytomegalovirus gB genotypes in solid-organ-transplant recipients by use of a real-time PCR assay

We have developed a real-time genotyping and quantitative PCR (RT-GQ-PCR) assay to genotype cytomegalovirus (CMV) and quantify viral loads simultaneously in solid organ transplant (SOT) recipients. Special minor-groove DNA-binding probes were designed based on sequence polymorphism in the gB gene to increase genotyping specificity for gB1 to gB4. For validation, 28 samples with known genotypes determined by restriction fragment analysis (RFA) and 121 with unknown genotypes were tested. All samples were from SOT patients with CMV viremia. A 100% concordance for genotyping was achieved by using the RT-GQ-PCR with known genotypes determined by RFA. The RT-GQ-PCR identified more cases of CMV infections with mixed genotypes than RFA did. No cross-reaction between genotypes was observed. All four gB genotypes were detected in the 121 samples of unknown genotype. gB1 was the predominant single genotype (n = 61, 50.4%), followed by gB2 (n = 26, 21.0%), gB3, (n = 11, 9.1%), and gB4 (n = 3, 2.5%). Mixed-genotype infections were detected in 17% (20/121) of the samples. Patients with mixed-genotype infections had significantly higher CMV viral loads than those with single-genotype infections (P = 0.019). The RT-GQ-PCR assay was found to be highly sensitive and specific, with a wide dynamic range (2.7 to 10.7 log₁₀ copies/ml) and very good precision (coefficient of variation, ~1.78%). With the prominent feature of concurrent CMV gB genotyping and quantitation in a single reaction, the new assay provides a rapid and cost-effective method for monitoring CMV infection in SOT recipients.