PCR—微孔板杂交法检测不同人群TTV DNA

根据报道的TTV全序列设计引物和探针,建立PCR－微孔板杂交法,检测81例正常人群、92例职业献血员123例甲－庚型肝炎、32例非甲－庚型肝炎、48型发性肝癌患者的TTV DNA。结果表明TTV在以上五种人群中的阳性率分别为3．7％、4．3％、21．1％、28．1％、52．0％,前者与后三者比较有显著性差异（P＜0．05）,TTV合并HBV二重感染重叠感染的54．0％,这揭示不同人群均存在TTV感染,正常人群和职业献血员存在健康携带状态,甲－庚型肝炎和非甲－庚肝炎病人为高危人群,TTV可与各型肝炎存在重叠感染,TTV除经血传播外,存在其它传播途径,TTV感染与ALT及TBIL的升高密切相关。     

延边地区丙型肝炎患者合并TT病毒感染的检测

检测丙型肝炎患者血清标本中的TT病毒 (transfusiontransmittedvirus,TTV) ,了解延边地区丙型肝炎患者合并TTV感染状况。采用ELISA检测抗TTVIgG和巢式PCR检测丙型肝炎病毒 (HCV)感染患者血清中TTVDNA。采用全自动生化分析仪检测患者血清谷氨酸氨基转移酶 (ALT)和谷氨酸草酰乙酸氨基转移酶 (AST)。 4 5例丙型肝炎患者抗TTVIgG阳性率为 37.8% (17/45 ) ,巢式PCR阳性率为 4 2 .2 % (19/45 )。延边地区HCV感染患者重叠感染TTV较常见。     

兰州地区无偿献血人群血清TTV-DNA的检测

为了解兰州地区人群TTV的感染状况,作者采用套式PCR法,以TTV-DNA的ORFl中的一段309nt的序列为扩增序列,对36份兰州地区无偿献血人群血清DNA进行扩增,将扩增阳性片段测序并进行序列同源性比较,结果发现兰州地区无偿献血人群TTV感染率为52．7％。10份兰州序列之间的同源性为88．6％～95．4％,兰州序列与日本TA287株的同源性为88．1％～93．3％,表明兰州地区无偿献血人群TIN感染非常普遍,兰州地区TTV流行株存在变异,至少有基因亚型存在。     

新肝炎病毒TTV在各类高危人群中的感染状况和分子流行病学研究

目的观察新肝炎病毒TTV在各类高危人群中的感染状况、基因分型及其在肝病发生和发展过程中的作用。方法在日本株TTVORF1保守区设计了两对套式引物,采用巢式聚合酶链反应扩增血清TTVDNA,并对产物进行分子克隆和部分基因序列分析。结果在非甲-戊型和非庚型肝炎病人、血清HBsAg阳性的肝炎病人、正常献血员、肝炎肝硬化病人、原发性肝癌病人、静脉内吸毒者和女性与男性性乱者中,血清TTVDNA阳性率分别为43.2％(16/37)、28.8％(15/52)、9.3％(4/43)、51.9％(14/27)、38.5％(5/13)、35.0％(14/40)、17.3％(8/45)和18.8％(3/16)。其中非甲-戊型和非庚型肝炎病人、血清HBsAg阳性肝炎病人的ALT平均为(472士276)u·L-1和(385士218)u·L-1;肝炎肝硬化病人TTVDNA阳性率显著高于HBsAg阳性肝炎病人。同时,从非甲-戊型和非庚型肝炎病人、血清HBsAg阳性肝炎病人、正常献血员、静脉内吸毒者和女性性乱者中,分别获得6份TTVDNAORF1克隆,其基因序列与日本株TTVORF1部分基因核苷酸序列同源性为97％～99％,均属于TTV1a型。结论TTV感染和ALT升高存在一定的关系;我国各类高危人群感染TTV以1a型为主,TTV基因型与疾病发生和传播方式关系不大。国内首次报导性传播的TTVDNA基因型。     

PCR-微孔板杂交法检测不同人群TTV DNA

根据报道的TTV全序列设计引物和探针,建立PCR-微孔板杂交法,检测81例正常人群、92例职业献血员123例甲～庚型肝炎、32例非甲～庚型肝炎、48例原发性肝癌患者的TTVDNA.结果表明TTV在以上五种人群中的阳性率分别为3.7%、4.3%、21.1%、28.1%、52.0%,前者与后三者比较有显著性差异(P＜0.05),TTV合并HBV二重感染占重叠感染的54.0%.这揭示不同人群均存在TTV感染,正常人群和职业献血员存在健康携带状态,甲～庚型肝炎和非甲～庚肝炎病人为高危人群,TTV可与各型肝炎存在重叠感染,TTV除经血传播外,存在其它传播途径,TTV感染与ALT及TBIL的升高密切相关.     

儿童抗幽门螺杆菌IgG和IgA水平的酶联免疫吸附试验检测

目的：了解北京地区儿童幽门螺杆菌（Hp)的感染状况,探讨儿童幽门螺杆菌感染与年龄、性别的关系,比较分析HP感染后血清中抗体(IgG、IgA)水平。方法：采用ELISA方法对我院消化道门诊227例患儿同时检测血清抗Hp抗体IgG、IgA,任一项阳性者即诊断为Hp感染。结果：(1)227例门诊患儿Hp平均感染率53．7％,男孩感染率57．1％,女孩48．1％。(2)3岁以下就诊儿童Hp感染率57．1％,4—7岁组39．1％,8—12岁组60．5％,13岁以上47．1％;其中66．9％(81／120)的Hp阳性患儿在8—12岁之间;(3)HP感染总阳性率53．7％;若单独检测IgG,阳性率42．7％,假阴性率11％;单独检测IgA,阳性率22％,假阴性率31．7％;两项诊断符合率达57．3％。结论：北京地区儿童幽门螺杆菌感染率较高。有消化道症状伴HP感染的患儿以8—12岁居多,其感染率明显高于全国无症状儿童平均染率。儿童Hp感染性别差异无显著性,感染后血清抗体水平IgG显著高于IgA,同时检测IgG、IgA有助于提高ELISA方法Hp的感染检出率。     

类风湿性关节炎患者EBV感染情况分析

目的:检测类风湿性关节炎患者血清EBV(Epstein-Barr virus)衣壳抗原IgA抗体(VCA-IgA),分析EBV感染与类风湿性关节炎的相关性.方法:用酶联免疫吸附试验(ELISA)检测92例确诊为类风湿性关节炎患者和80例体检健康者血清VCA-IgA抗体,分析两组人群EBV VCA-IgA阳性率.结果:类风湿性关节炎患者VCA-IgA抗体阳性率为9.8％(9/92);健康对照组阳性率为2.4％ (2/85)(x2=4.038,P＜0.05).结论:类风湿性关节炎患者血清EBV VCA-IgA抗体检出率明显高于健康对照组,提示部分类风湿性关节炎患者发病与EBV感染有关.     

孕妇尿液人巨细胞病毒DNA筛查及血液HCMV抗体测定的对照研究

目的对于孕妇尿液进行HCMV—DNA筛查,减少和有效地避免胎儿及新生儿的HCMV感染。HCMV．DNA筛查同时进行HCMV抗体检测,明确诊断HCMV感染的灵敏、准确方法。方法应用荧光定量PCR（FQ．PCR）方法进行尿液HCMV-DNA测定。血液HCMV IgM、IgG抗体检测应用酶联免疫（ELISA）方法。结果筛查6568例孕妇尿HCMV．DNA,阳性273例,阳性率为4．2％。孕妇在12—20周者,阳性率为10．3％;孕妇在21～30周者,阳性率为33．3％;孕妇在31～39周者,阳性率为56．4％。在273例尿液HCMV—DNA阳性者中,56例同时进行血液HCMV IgM、IgG抗体检测,Igi抗体阳性者2例,IgG抗体阳性者22例。结论在孕妇HCMV感染的筛查与诊断中FQ．PCR是灵敏准确的方法。孕妇中HCMV—DNA筛查是保证母婴健康,提高人口素质的保障。     

安徽北部地区恶性肿瘤人群卡波氏肉瘤相关疱疹病毒血清学分析

卡波氏肉瘤相关疱疹病毒是一种新发现的γ疱疹病毒(Kaposi'ssarcoma-associated herpesvirus,KSHV).在中国新疆,KSHV感染率比较高,KSHV在免疫缺陷患者和静脉吸毒者中感染率也比在普通人群中高.为了进一步研究KSHV在安徽北部地区恶性肿瘤人群中的感染率和高风险因素,初步探讨KSHV与肿瘤的发生之间相关性,研究KSHV的高发人群特点,本研究选用KSHV病毒重组蛋白ORF65、ORF 73和K8.1为抗原,利用酶联免疫吸附实验(ELISA)对500份恶性肿瘤患者血清样本及200份健康体检人群血清样本进行KSHV抗体检测,分析KSHV的感染率及危险因素.结果显示500例肿瘤患者KSHV阳性总数170例,总阳性率为34％,200份健康人群KSHV阳性总数22例,总阳性率为11％,肿瘤人群KSHV阳性率明显高于健康人群(P＜0.001).其中肺癌、肝癌、结肠癌、宫颈癌、乳腺癌样本KSHV阳性率分别为36.4％,34.1％,41.7％,28.6％,30.3％,此5组肿瘤组KSHV阳性率也分别高于健康人群,都具有统计学意义(P＜0.001).但5组肿瘤样本之间KS-HV阳性率无明显差异(P＞0.05),且各组肿瘤样本分别与性别、乙肝五项、丙肝之间无统计学意义(P＞0.05).本研究结果提示安徽北部地区恶性肿瘤患者KSHV抗体阳性率显著高于中国普通人群总体KSHV抗体阳性率,证明KSHV在恶性肿瘤人群中呈现较高比例的分布.     

中国部分地区猪细环病毒1型和2型的分子检测

细环病毒(TTV)是近年来发现的一种新型人畜共患DNA病毒,广泛存在于包括人类和家畜在内的多种哺乳动物中。目前我国猪群中TTV的流行病学报道较少。为研究猪细环病毒(PTTV)在我国的流行情况,采用聚合酶链反应(PCR)对2009年我国9个省市部分发病猪场中的PTTV1和PTTV2进行检测。结果显示,191份病料中PTTV的总阳性率为77.0%(147/191),其中PTTV1的单一阳性率为68.6%(131/191),PTTV2的单一阳性率为53.9%(103/191),两基因型的共感染率为45.5%(87/191)。进一步分析发现,在不同猪场、不同年龄猪群、不同病料组织中,PTTV的感染情况均不相同。此外,对41份健康猪的血清进行检测,结果显示,PTTV总阳性率、PTTV1单一阳性率、PTTV2单一阳性率及两基因型的共感染率分别为43.9%(18/41)、36.6%(15/41)、24.4%(10/41)和12.2%(5/41)。结果提示,发病猪体内PTTV总阳性率、PTTV1单一阳性率、PTTV2单一阳性率及两基因型的共感染率均显著高于健康猪(P0.01)。PTTV在临床上是否对猪致病或与其他病原有协同作用,需进一步研究。     

浙江省献血员HGV和TTV感染情况的调查

应用逆转录套式聚合酶链反应(RT-Nested PCR)和半套式聚合酶链反应(Semi-nested PCR)分别检测来自浙江省3个地区165例献血员血清标本中的庚型肝炎病毒(HGV)RNA和输血传播性病毒(TTV)DNA.14.6%(24/165)和12.7%(21/165)的血清标本分别检出HGV RNA和TTV DNA,其中3.6%的血清标本(6/165)可同时检出HGV RNA和TTV DNA.实验结果表明,浙江省献血员中HGV和TTV的感染率较高.     

New Phylogenetic Groups of Torque Teno Virus Identified in Eastern Taiwan Indigenes

Torque teno virus (TTV) is a single-stranded DNA virus highly prevalent in the world. It has been detected in eastern Taiwan indigenes with a low prevalence of 11% by using N22 region of which known to underestimate TTV prevalence excessively. In order to clarify their realistic epidemiology, we re-analyzed TTV prevalence with UTR region. One hundred and forty serum samples from eastern Taiwanese indigenous population were collected and TTV DNA was detected in 133 (95%) samples. Direct sequencing revealed an extensive mix-infection of different TTV strains within the infected individual. Entire TTV open reading frame 1 was amplified and cloned from a TTV positive individual to distinguish mix-infected strains. Phylogenetic analysis showed eleven isolates were clustered into a monophyletic group that is distinct from all known groups. In addition, another our isolate was clustered with recently described Hebei-1 strain and formed an independent clade. Based on the distribution pattern of pairwise distances, both new clusters were placed at phylogenetic group level, designed as the 6th and 7th phylogenetic group. In present study, we showed a very high prevalence of TTV infection in eastern Taiwan indigenes and indentified new phylogenetic groups from the infected individual. Both intra- and inter-phylogenetic group mix-infections can be found from one healthy person. Our study has further broadened the field of human TTVs and proposed a robust criterion for classification of the major TTV phylogenetic groups.     

TT virus infection in children and adults who visited a general hospital in the south of Brazil for routine procedure

TT virus (TTV) is a newly described nonenveloped human virus, with a circular, negative-stranded DNA genome, that was first identified in the blood of a patient with posttransfusion hepatitis of unknown etiology. PCR primers and conditions used for TTV DNA amplification may greatly influence the level of TTV detection in serum. Three PCR assays, with different regions of the genome as targets, were used to test TTV DNA in 130 sera from children and adults visiting a hospital in the south of Brazil, most of them for routine procedure. Forty-four percent of adult sera and 73% of sera from children aged 0-10 years were TTV positive with at least one PCR assay. However, the three assays were able to detect only 33%, 35%, and 70% of the total positive samples. Our results showed a high prevalence of TTV infection in the south of Brazil, particularly among young children, and confirmed the necessity of performing several PCR assays to assess the true TTV prevalence in a determined population.     

High prevalence of human Torque teno virus in streams crossing the city of Manaus, Brazilian Amazon

Aims:  Torque teno virus (TTV) is a human DNA virus chronically infecting most healthy individuals worldwide and can be transmitted by faecal–oral route. The occurrence of TTV was evaluated in the streams crossing the city of Manaus (Brazilian Amazon) over a 1-year period, four times a year.
Methods and Results:  Fifty-two water samples were collected from 13 different locations. Viruses were concentrated from two litres of water by adsorption to negative membrane filters followed by ultrafiltration. TTV DNA was detected by PCR assays designed to detect all five TTV genomic groups. By conventional PCR, 19/52 (37%) samples were positive. By real-time PCR, TTV DNA could be detected in 48/52 (92%) samples. Viral loads ranged from 1300 to 746 000 genome equivalent per 100 ml of river water. Eleven distinct nucleotide sequences were obtained.
Conclusions:  Our results show the wide distribution and diversity of TTV among Manaus urban micro basins.
Significance and Impact of the Study:  The data presented here may contribute to substantiate TTV as a sensitive indicator of human contamination.     

TT virus in Hungary: sequence heterogeneity and mixed infections

The majority of the viral hepatitis cases is caused by five hepatitis viruses (A,B,C,D,E). In 1997, TT virus was discovered. It was supposed that a number of the unknown hepatitis cases was caused by the TT virus. The aim of this study was to characterize TT viruses carried by healthy individuals and patients suffering from hepatitis of unknown origin in Hungary. TTV DNA was detected by seminested PCR with the commonly used N22 primers. Twenty of the 108 sera (18.5%) taken from healthy persons and 115 of the 228 sera (50.4%) of patients with hepatitis of unknown origin were found to be positive. The nucleotide sequences of 26 clones derived from 17 hepatitis patients and 15 clones from nine healthy persons were determined and a phylogenetic tree was constructed. Genotype 2 (group 1) was found to be the most frequent, but other group 1 genotypes (1, 6) and genotypes 8 and 17 of group 2 were also detected. Mixed TTV infections were found in eight cases (two healthy persons and six hepatitis patients). Variants belonging to the same group were carried in seven cases, and the presence of group 1 (genotype 2) and group 2 (genotype 8) TTV sequences were found in one single hepatitis patient.     

TT型病毒基因组的克隆与进化分析

利用PCR方法从输血传播性病毒 (transfusiontransmittedvirus,TTV)阳性标本中获得不同长度且重叠覆盖TTV基因组的DNA片段。将PCR扩增片段克隆到pT Adv载体中 ,筛选获得阳性克隆。DNA序列测定结果表明所克隆的片段为TTV基因组序列。利用DNA片段中特有的限制性内切酶位点将TTV的DNA片段首尾相连 ,得到近全长的基因组克隆 ,命名为TTV0 2 1。对TTV0 2 1的核酸序列进行分析 ,TTV0 2 1长 3472nt,存在 2个阅读框架ORF1和ORF2 ,分别编码 785和 1 46个氨基酸。将TTV0 2 1与其它已知的TTV基因组全序列进行了同源性比较 ,并进行进化分析。结果表明 ,TTV0 2 1序列与TTV分离株CHN2、BDH1的遗传距离较近 ,而与其它分离株相对较远。     

Association of cytomegalovirus with infantile hepatitis

Infantile hepatitis is occasionally seen in apparently healthy children. In most cases, the etiology of the infection is uncertain. However, cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), human parvovirus B19, and TT virus (TTV) are considered to be associated with hepatitis in children. The objective of this study was to investigate the correlations between these viruses and infantile hepatitis. Twenty-six children from 1 to 24 months old (median age, 7 months) who had liver dysfunction of unknown etiology were enrolled in this study. Plasma samples were examined by a real-time PCR assay for CMV, EBV, HHV-6, HHV-7, parvovirus B19, and TTV DNA. The DNA of CMV was detected in the plasma of four patients (15.4%) and was detected significantly more often in the patient group than in the control group. The CMV-infected patients were 1 to 3 months old, which was significantly younger than the remaining patients. The serological findings did not always correlate with the results of the real-time PCR assay. The DNA of TTV was detected in four patients (15.4%), while human parvovirus B19 DNA was detected in three (11.5%). However, the detection frequencies of these viral DNAs were not significantly different from those in the control groups, and some of these patients had co-infections. These results indicate that CMV might be one of the major pathogens responsible for infantile hepatitis; however, serological tests have limited utility for the diagnosis of CMV infection in young children.     

Presence of TT virus DNA in bone marrow cells from hematologic patients

Recent observations suggest that TT virus (TTV), in addition to liver, may also infect bone marrow. In this study, bone marrow samples and sera from 33 patients with haematological disorders and sera from 16 healthy controls were investigated for TTV DNA presence. Altogether TTV DNA sequences were demonstrated in bone marrow cells of 84.84% of patients. Moreover TTV DNA was detected in sera from 72.72% of patients and from 93.75% of controls. N22 sequences amplified from bone marrow cells and serum of 3 patients were analysed, after cloning: all these isolates were of type 2c and 2 or 3 variants were present in each isolate. After single strand DNA degradation, replicative forms were detectable in BM cells. This finding, in addition to the detection of variants similar in the BM and in the serum of the same patient could suggest that BM is a site of TTV replication (or one of the sites) from which the virus is spread in blood.