人巨细胞病毒临床分离株糖蛋白B基因型分析

目的 分析巨细胞病毒临床分离株糖蛋白B基因型。方法 以巢式聚合酶链反应(nested-PCR)检测器官移植受者外周血细胞和输卵管妊娠患者生殖道组织中的巨细胞病毒gBn和gBcls基因并测序分型。结果 分离到44例HCMV gBn、gBcls阳性基因，32例有HCMV gBn基因分型结果，其中l型8例(25％)，2型2例(6％)，3型22例(69％)，未见4型，分布以gBn3型为主。HCMV gBcls基因分型结果为26例，其中l型14例(54％)，2型5例(20％)，3型7例(26％)，未见4型，gBcls基因型则散在分布，以1型为多见。21例同时得到gBn、gBcls基因分型结果，其中8例(36％)表现出基因型别不一致。表现为gBclsl-gBn3型。结论 HCMV临床分离株，其糖蛋白基因分别属于gB基因型l-3型，并存在较多的gBcls与gSn基因型别的不对应现象，提示HCMV临床株有较高频率株内基因重组发生，是否由此导致病毒抗原性发生改变，值得进一步研究.     

新生儿晚期黄疸人巨细胞病毒gB基因分型研究

目的了解引起新生儿晚期黄疸患者人巨细胞病毒（HCMV）gB基因型的分布,探讨HCMVgB基因多态性与黄疸之间的关系。结论采用荧光定量PCR法检测本院新生儿科98例晚期黄疸新生儿标本HCMV-DNA含量,巢式聚合酶链反应扩增阳性标本HCMVgB基因,并进行DNA测序,绘制种系进化树。利用HinfⅠ和RsaⅠ对gB基因进行限制性片段长度多态性（RFLP）分析。结果 30例晚期黄疸新生儿HCMV荧光定量PCR检测阳性,阳性率为30.6%。种系进化树分析结果显示gB基因分为4个基因型,gB1型15株（50%）,gB2型5株（16.7%）,gB3型9株（30.0%）,gB1/3混合型1株（3.3%）。以HCMV实验室标准株AD169作为参考,将序列进行同源性比较,gB1型同源性为94.7%～95.0%,gB2型同源性93.1%～93.4%,gB3型同源性94.7%,gB1/3型同源性93.7%。RFLP分析将gB基因分为4个基因型,分型结果与种系进化树分型一致。结论 HCMV感染是导致新生儿晚期黄疸的原因之一;gB基因的DNA序列比较保守,但仍存在一定的多态性,晚期黄疸新生儿中HCMV感染以gB1、gB3型为主。     

先天性巨细胞病毒感染新生儿gB基因分型研究

目的 探讨先天性巨细胞病毒（HCMV）感染的新生儿gB基因分型与临床表现的关系。方法采集67例经PCR方法确诊的有症状的先天性HCMV感染新生儿尿液标本。用巢式PCR方法扩增尿液标本中gB基因片段,用限制性片段长度多态性分析检测gB基因分型。结果 67例病例中最常见的基因型为gB1 （50.7％）,其次为gB3 （23.9％）,gB2 （17.9％）和gB1/gB3混合感染（7.5％）,gB4基因型未检测到。在有肝脏损害的患儿中,gB1基因型最为常见（27/37,73.0％）,高于无肝脏损害的其他有症状感染患儿（ 13/30,43.3％;P＜0.05）。结论 在有症状的先天性HCMV感染新生儿中最常见的gB基因型为gB1,其次是gB3、gB2及gB4。     

HCV反向点杂交基因分型方法的建立

目的利用反向点杂交技术建立HCV基因分型新方法。方法在HCV5’端非编码区（5’NCR）设计引物和分型探针（1．2．3．6型）,采用反向点杂交分型技术对53例HCVRNA阳性（浓度均在102～107IU／mL之间）血清进行分型,并以基因序列分析作为金标准,对新方法的敏感性、特异性和重复性进行评价。结果反向点杂交基因分型新方法检出的基因型有52例：1b型32例占60．38％,2a型4例占7．55％,6a型8例占15．09％．3b型8例占15．09％;未检出的基因型有1例,用基因序列分析也未能确定型别（失败的原因应是该HCVRNA扩增产物浓度偏低2．24×10^2IU／mL）。本研究的方法敏感性为98．1％,特异性为100％,随机抽取20份标本再次检测的结果与前次检测的结果完全一致,重复性好。结论相对现有的型特异性PCR分型、基因芯片、核酸序列分析等各种方法,反向点杂交技术用于HCV基因分型是一种准确有效和简便经济的方法。     

成都地区HBV基因型分布研究

目的 调查成都地区乙型肝炎患者外周血中乙型肝炎病毒（HBV）基因型的分布情况。方法 以长片段高保真聚合酶链反应（LA—PCR）扩增乙肝病毒S基因区，结合双脱氧链末端终止法（Sanger）测序技术对该地区90例乙型肝炎患者感染的HBV进行基因分型；同时与常用的基因型特异引物扩增分型法获得的分型结果进行比较，做重复试验以证实所用方法的可靠性和准确性。结果 S基因直接测序法检测成都地区人群HBV基因分型结果为B基因型57例（63．3％）、C型30例（33．3％），D型3例（3．3％），无其他基因型和混合型；基因型特异引物分型法除检出23例（25．5％）混合基因型外，其他各例结果均与S基因测序法吻合。结论 成都地区HBV优势基因犁以B型为主，C型次之，偶见D型。S基因直接测序法能准确鉴定HBV基因型，并较好地反映HBV基因组变化的准种特征，总体上优于型特异引物分型法，此结论具有统计学意义（P〈0．001）。     

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.     

PCR-荧光探针法检测庆阳地区丙型肝炎病毒基因型

目的:应用PCR-荧光探针法分析庆阳地区丙型肝炎患者基因型,并对PCR-荧光探针法的各种性能进行评价。方法:收集庆阳地区289 例各种丙型肝炎患者的临床资料和外周静脉血,采用PCR-荧光探针法检测其基因型,并和PCR-反向点杂交法、测序法进行比较。结果:289 份HCV RNA 阳性血清标本中,PCR-荧光探针法基因型及亚型检出率为99.3%(287/289),其中1b 型139 例(48.1%),2a 型136 例(47.1%),3a 型7 例(2.4%),3b 型5 例(1.7%),未分出型2 例(0.7%)。PCR-荧光探针法的特异度和准确度为100%,重复性良好,并与PCR-反向点杂交法、巢式PCR 测序法分型结果均一致,三种方法的一致率为98.2%(56/57),差异无统计学意义(P>0.05)。1b 基因型患者ALT、AST、PLT 和HCVRNA(lg)水平均高于2a基因型患者,差异具有统计学意义(P<0.05)。结论:庆阳地区HCV 基因型呈现多基因型分布特点,主要为1b 型和2a 型,且2a 型和1b 型的比例相当,呈现出2a 型比例升高,1b 型下降的趋势;PCR-荧光探针法HCV 基因分型敏感度和特异度高,方法简单,适合临床实验中应用。     

广州成人散发急性腹泻中诺瓦克样病毒感染及毒株型别初步研究

目的探讨诺瓦克样病毒与广州成人散发急性腹泻的病原关系和感染毒株的基因型别。方法采用ELISA方法筛检轮状病毒，RT-PCR方法检测诺瓦克样病毒，诺瓦克样病毒阳性样品的PCR产物经纯化、测序后进行基因分型。结果35份成人散发急性腹泻患者粪便标本中检出轮状病毒8例，诺瓦克样病毒4例，测序分析确定1株为诺瓦克样病毒GⅡ-3型，另1株为GⅡ-4型。结论广州成人散发急性腹泻患者中存在诺瓦克样病毒感染，且感染毒株的基因型别不一。     

SNaPshot技术检测乙型肝炎病毒基因组P基因区单核苷酸多态性的研究

目的　建立SNaPshot技术对乙型肝炎病毒(HBV)基因组P基因区单核苷酸多态性(SNP)的分析。方法　针对HBVYMDD变异位置的上、下游设计引物,用PCR方法进行DNA扩增,产物直接测序或克隆测序。再针对变异位点74 1A G变异型(YVDD)和74 3G T变异型(YIDD)的紧邻上游设计高度特异的SNaPshot检测引物,用不同荧光标记的ddNTP对PCR产物进行一步延伸,然后置于310型DNA测序仪上观察荧光信号,可直观的检测上述两位点的单核苷酸多态性。结果　在拉米夫定治疗的慢性乙型肝炎患者中,经测序证实P基因区不仅存在74 1、74 3位点的变异,还存在5 14C A、5 2 3C A、5 6 2T A、6 6 7C A等位点的变异。对已证实P基因区变异的13例患者血清用SNaPshot技术检测YMDD结果与测序结果完全相同,显示SNaPshot技术高度的特异性。结论　SNaPshot技术检测HBV基因组SNPs具有快速、简便、准确特异的特点,还检测到野生株和变异株的混合存在。     

等位基因特异荧光PCR法检测CYP2C19基因型

目的了解人群CYP2C19基因型的分布,评价等位基因特异荧光PCR法检测CYP2C19基因型。方法等位基因特异荧光PCR法和金标准Sanger DNA直接测序法检测356名供者外周血CYP2C19基因型,实验采用同步盲法。结果 CYP2C19*1/*1型、CYP2C19*1/*2型、CYP2C19*2/*3型、CYP2C19*3/*3型、CYP2C19*2/*2型及CYP2C19*1/*3型的频率分布:使用PCR荧光法检测时分别为46.6%(166/356)、33.2%(118/356)、2.0%(7/356)、0.8%(3/356)、10.7%(38/356)及6.7%(24/356);采用DNA测序法时分别为46.3%(165/356)、33.4%(119/356)、2.0%(7/356)、0.8%(3/356)、11.0%(39/356)及6.5%(23/356)。两种方法检测CYP2C19基因型具有一致性(P=0.392),且一致性较好(Kappa=0.987);两种方法基因型检测结果一致率为99.2%。结论为保障医疗安全,临床需开展CYP2C19基因型检测;等位基因特异荧光PCR法检测CYP2C19基因型简便可靠。     

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.     

Human cytomegalovirus envelope glycoprotein B,H, and N polymorphisms among infants of Shanghai area in China

Human cytomegalovirus (HCMV) is the leading cause of congenital infection and an opportunistic pathogen capable of establishing lifelong latency. In the present study, we aimed to investigate the distribution of glycoprotein B, H, and N in infants of Shanghai and correlate the genotype with active and latent HCMV infection. A total of 129 urine samples were collected between August 2014 and December 2015 from infants under 3 years with HCMV infection. Nested PCR was used to amplify the regions of UL55 (gB), UL75 (gH), and UL73 (gN). Gene sequencing and phylogenetic analyses were used to classify the genotypes. Overall, regarding gB, gB1 (57.27%) was predominant, followed by gB3 (41.82%) and gB4 (0.91%). gH1 (54.33%) was the most prevalent genotype of gH, followed by gH2 (45.67%). Concerning gN, we detected gN1 (17.44%), gN2 (2.33%), gN3a (29.07%), gN3b (8.14%), gN4a (13.95%), gN4b (15.12%), and gN4c (13.95%), among which gN3a was the dominant genotype. All the expected genotypes were present except gB2 in children with active infection: gB1 (56.25%), gB3 (42.5%), gB4 (1.25%), gH1 (58.70%), gH2 (41.30%), gN1 (19.05%), gN2 (3.17%), gN3a (25.40%), gN3b (6.35%), gN4a (15.87%), gN4b (17.46%), and gN4c (12.70%). However, among latent cases, we detected gB1 (60%), gB3 (40%), gH1 (42.86%), gH2 (57.14%), gN1 (13.04%), gN3a (39.13%), gN3b (13.04%), gN4a (8.70%), gN4b (8.70%), and gN4c (17.39%), respectively. gB2, gB4, and gN2 were absent in this group. The results revealed that gB1, gH1, and gN3a were predominant in the infants of Shanghai. gH showed different trends among children with active and latent infection.     

Human cytomegalovirus glycoprotein B genotypes in blood of AIDS patients: Lack of association with either the viral DNA load in leukocytes or presence of retinitis

It has been suggested that human cytomegalovirus (HCMV) glycoprotein B (gB) genotypes could be used as a marker for viral virulence in patients with AIDS. The present study was designed to evaluate a possible association between specific gB genotypes, the presence of HCMV retinitis, and the HCMV viral load. Fifty-four blood samples were obtained from 54 HIV- and HCMV-infected patients. Twenty-seven of these patients were asymptomatic for HCMV, whereas the other 27 patients had been diagnosed recently with HCMV retinitis. HCMV gB genotyping was carried out by using restriction enzyme analysis of PCR-amplified PMNL extracts. Determination of the HCMV viral load in the same specimens was carried out using a quantitative-PCR. HCMV gB genotype 2 was found more frequently than other genotypes in PCR-amplified polymorphonuclear leukocytes (PMNL) of patients with AIDS (P < 0.05) but not more frequently in samples from patients with HCMV retinitis. No significant association was found between any HCMV gB genotypes and the viral load in blood. In conclusion, the actual HCMV gB genotyping system using PMNL provides no additional benefit over the viral load in blood for identification of HIV-infected subjects at risk of HCMV disease. J. Med. Virol. 59:98–103, 1999. © 1999 Wiley-Liss, Inc.     

Identification of human cytomegalovirus variants by analysis of single strand conformation polymorphism and DNA sequencing of the envelope glycoprotein B gene region-distribution frequency in liver transplant recipients

Single strand conformation polymorphism analysis (SSCP) of PCR-amplified DNA and subsequent DNA sequencing of human cytomegalovirus (HCMV) glycoprotein B (gB) gene were applied to identify known HCMV strains and to detect new virus variants. 61 HCMV PCR positive patients were studied out of a cohort of 410 patients after liver transplantation (LTX). SSCP was able to distinguish between strains Davis, AD169, and Towne, and in addition could identify five new virus variants (Berlin B, C, E, F, and H). Their frequency, gB and gH types were determined. Simultaneous infections with two or three strains or variants, as well as a switch from one virus to another virus were observed during long-term follow-up. No correlation between the occurrence of certain virus strains or gB types and defined clinical manifestations of HCMV infection after LTX was drawn.     

Distinct genotypic distributions of cytomegalovirus (CMV) envelope glycoprotein in bone marrow and renal transplant recipients with CMV disease.

A prospective study of the spectrum of glycoprotein B (gB) and glycoprotein H (gH) genotypes of cytomegalovirus (CMV) was conducted with five categories of patients: viremic bone marrow-transplant (BMT) recipients who developed CMV disease after BMT (n = 22), viremic BMT recipients without CMV disease (n = 11), viremic renal-transplant recipients who developed CMV disease after transplantation (n = 14), viremic renal-transplant recipients without CMV disease (n = 13), and premature babies with asymptomatic congenital CMV infections (n = 13). Genotypic stability was observed because the gB and gH genotypes of multiple isolates obtained from a single patient were identical. The distribution of gH genotypes in patients of all groups studied were similar. However, there was a unique distribution of the gB genotype in the first category of patients, i.e., BMT recipients with CMV disease, which was distinct from those of all other categories (P < 0.05). CMV isolates from 54% of BMT recipients with CMV disease exhibited gB type 2, while isolates from 46, 50, 69, and 77% of the BMT recipients without CMV disease, renal-transplant recipients with and those without CMV disease, and premature babies with congenital CMV infection, respectively, were of gB type 1. An analysis of the clinical characteristics of BMT recipients with CMV disease indicated that all underwent either an allogeneic or matched, unrelated donor transplant, and half had severe acute graft-versus-host disease (grades 2 to 4). The statistically significant genotypic difference between CMV isolates from BMT recipients with and without CMV disease was not observed between isolates from renal-transplant recipients with and without CMV disease. We speculate that differences in pathogenesis in different patient groups might account for these observations. These findings would also facilitate decision making about the choice of recombinant CMV glycoprotein vaccine required to immunize transplant donors and the subsequent adoptive transfer of immunity to BMT recipients. When the source of CMV DNA required for genotyping was investigated among renal-transplant recipients, direct use of peripheral blood leukocytes was 95% effective compared to the effectiveness of cells obtained from conventional culture of peripheral blood specimens.     

Human cytomegalovirus glycoprotein B genotypes in Brazilian mothers and their congenitally infected infants

A case-control study design was used in order to compare the distribution of human cytomegalovirus (HCMV) glycoprotein B (gB) genotypes in 48 mothers of 49 congenitally infected infants with that observed in 144 mothers of 146 uninfected infants to study genetic variation of HCMV strains and maternal-fetal transmission. Congenital infection with HCMV was characterized by DNA detection and virus isolation from two urine or saliva samples collected prior to the third week of life. Genotyping of HCMV was carried out by a polymerase chain reaction-restriction fragment length polymorphism analysis of the variable region of the gB gene, testing for four genotypes. Genotype frequency was similar among the 28 non-transmitting mothers who were shedding virus (gB1: 25%; gB2: 28.6%; gB3: 42.8%; gB4: 0%), the 37 transmitting mothers (gB1: 21.6%; gB2: 46%; gB3: 27%; gB4: 0%), and the 49 infected infants (gB1: 39%; gB2: 37%; gB3: 24%; gB4: 0%). The same genotype was detected at different body sites (urine, saliva, and blood) of each infected newborn and in the respective mother (breast milk, urine, and saliva). Co-infection with multiple genotypes was observed in the immediate postpartum period in two mothers of infected infants (5.4%) and one non-transmitting mother (3.6%). The gB genotype was not correlated with intrauterine HCMV transmission. The genotype distribution found reflects the overall frequency of wild strains circulating in this geographic region. A single genotype is responsible for congenital HCMV infection. Co-infection with more than one strain, as characterized by gB genotype, was infrequent in women who were presumably immunocompetent.     

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.     

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.