我国急性呼吸道感染患儿中检测到KI和WU多瘤病毒

目的 了解多瘤病毒WU和KI在我国儿童急性呼吸道疾病中的感染情况.方法 采用PCR扩增的方法对2006年11月至2007年10月收集的急性呼吸道感染患儿的318份鼻咽抽吸物(NPA)标本进行了多瘤病毒WU和KI基因检测.结果 318份标本共检测出14份病毒核酸阳性标本,其中WUV 7份(2.2%),KIPyV 7份(2.2%).该14例基因检测阳性患儿临床均有上呼吸道感染或下呼吸道感染症状.结论 WUV和KIPyV可能也是儿童急性呼吸道感染中较为重要的一个病原,且与儿童上呼吸道感染和下呼吸道感染存在相关性.     

WU多瘤病毒-新发现的人类多瘤病毒的研究概况

随着人类多瘤病毒的不断被发现,人们对它的研究兴趣也越来越大.自2007年人类WU多瘤病毒(WU polyomavirus,WUPyV)在呼吸道标本中被发现以来,世界各地陆续发表了发现WUPyV的报道.WUPyV在全世界广泛流行,可能在儿童时期获得感染,但大多数不表现临床症状.尽管WUPyV经常在呼吸道标本中发现,但是WUPyV是否为呼吸道疾病的病原还有争议.WUPyV的传播途径和流行性也有待进一步的研究.目前该病毒的流行病学资料主要来自PCR检测和血清学试验.本文现就WU多瘤病毒的研究进展作一综述.     

WU多瘤病毒-新发现的人类多瘤病毒的研究概况

随着人类多瘤病毒的不断被发现,人们对它的研究兴趣也越来越大.自2007年人类WU多瘤病毒(WU polyomavirus,WUPyV)在呼吸道标本中被发现以来,世界各地陆续发表了发现WUPyV的报道.WUPyV在全世界广泛流行,可能在儿童时期获得感染,但大多数不表现临床症状.尽管WUPyV经常在呼吸道标本中发现,但是WUPyV是否为呼吸道疾病的病原还有争议.WUPyV的传播途径和流行性也有待进一步的研究.目前该病毒的流行病学资料主要来自PCR检测和血清学试验.本文现就WU多瘤病毒的研究进展作一综述.     

WU多瘤病毒-新发现的人类多瘤病毒的研究概况

随着人类多瘤病毒的不断被发现,人们对它的研究兴趣也越来越大.自2007年人类WU多瘤病毒(WU polyomavirus,WUPyV)在呼吸道标本中被发现以来,世界各地陆续发表了发现WUPyV的报道.WUPyV在全世界广泛流行,可能在儿童时期获得感染,但大多数不表现临床症状.尽管WUPyV经常在呼吸道标本中发现,但是WUPyV是否为呼吸道疾病的病原还有争议.WUPyV的传播途径和流行性也有待进一步的研究.目前该病毒的流行病学资料主要来自PCR检测和血清学试验.本文现就WU多瘤病毒的研究进展作一综述.     

人博卡病毒LAMP检测方法的建立及初步应用

目的 建立环介导等温扩增技术（LAMP）检测人博卡病毒（Human bocavirus,HBoV）基因的方法,并用于检测临床样本.方法 通过在线软件设计工具Ptimer Explorer V4设计HBoV NP-1基因的LAMP引物,建立LAMP检测方法,并评价其灵敏度和特异度.结果 与传统PCR方法相比,LAMP法检测灵敏度更高,可达到10拷贝,特异性较强;在76份呼吸道感染儿童的咽拭子标本中检测到5份阳性.结论 建立HBoV LAMP检测方法灵敏特异,简单快速,有望进行临床检测HBoV.     

荧光定量聚合酶链反应检测乙型肝炎病毒DNA

目的 建立检测HBV病毒DNA的荧光定量PCR法（FQ-PCR），并与运用常规凝胶电泳技术观察特异扩增带检测的结果加以比较。方法 合成扩增HBV DNA314bp特异保守序列的1对引物及1条带2个荧光基团的寡核苷酸探针。用PE-5700型定量PCR仪完成PCR反应及产物的荧光定量检测。同是PCR产物经琼脂糖凝胶电泳，EB染色，UVP（凝胶成像仪）检出有314bp带者为阳性或弱阳性。结果 建立了检测HBVDNA的荧光定量PCR技术，用已知HBV阳性模板不同拷贝数的标准溶液测得标准曲线Ct，原始拷贝数在10^5/ml以上者为阳性，用定量及定性PCR2种方法检测698例血清标本的结果表明：用FQ-PCR技术共检测出204例为阳性，阳性率29.2%；用定量及定性PCR2种方法检测698例血清标本的结果表明：用FQ-PCR技术共检测出204例为阳性，阳性率29.2%；用定性PCR观察到193例有阳性特异带，阳性检出率为27.65%。没有发现用定性PCR检测为阳性而用FQ-PCR检测为阴性者。结论 FQ-PCR检测HBVDNA较普通定性PCR技术具有操作简便，灵敏度更高、减少发生污染可导致假阳性结果的可能性及自动化程度高等优点，值得在临床检验中推广应用。     

荧光定量RT-PCR在流感病毒检测上的应用

目的　探讨实时荧光定量RT PCR检测方法在流行性感冒检测诊断上的意义。方法　收集集体暴发疑似流感、SARS患者的咽拭子标本 16起 2 0 7份和双份血清标本 10 4份 ,应用荧光定量RT PCR检测方法、MDCK细胞培养法和血凝抑制试验进行病原学和血清学检测。结果　 2 0 7份集体暴发疑似流感、SARS患者的咽拭子标本中用荧光定量RT PCR检测 ,阳性 79份。阳性率 38 16 % (79 2 0 7)。MDCK细胞培养 ,16起中有 13起共 14 5份咽拭子有 6 2份标本阳性。阳性率 2 9 95 % (6 2 2 0 7)。两者的阳性率差异有显著意义 (χ2 =8.6 4 ,P <0 0 0 5 )。有 9起 10 4份成功的采集了双份血清 ,经HI试验有 6 4份双份血清与H3N2亚型抗原产生血抑 4倍增长 ,阳性率 6 1 5 4 % (6 4 10 4 )。结论　荧光定量RT PCR方法检测流感病毒能够在 3～ 4h内得出结果、且操作方便、特异性强、灵敏度高。因此我们认为实时荧光定量RT PCR方法 ,可作为一种快速的流感病毒检测诊断方法。     

胃肠道恶性肿瘤C-myc基因荧光PCR方法的研究

目的建立胃肠癌中C-myc基因的荧光定量PCR(FQ-PCR)方法。方法胃肠癌细胞中的C-myc基因与质粒PGEM-T Easy Vector重组,转化大肠杆菌E.coli DH5α,获得克隆的C-myc基因标准模板。用ABI PRISM 7700PCR仪检测FQ-PCR扩增产物制成标准曲线来检测未知标本中C-myc的含量。结果 FQ-PCR扩增产物呈"S"形动力学曲线;ct(循环阈值)与PCR体系中起始模板拷贝数的对数值之间存在严格的线性关系,显示了FQ-PCR定量的准确性。结论 FQ-PCR是一种快速、简便、灵敏、准确的定量C-myc基因的方法。     

WU多瘤病毒衣壳蛋白原核表达及初步分析

目的 获得WU多瘤病毒重组衣壳蛋白,分析其抗原性,筛选具有诊断价值的抗原.方法 采用PCR技术扩增WU多瘤病毒衣壳蛋白VP1、VP2和VP3的基因片段,并将目的基因插入PGEX-20T表达载体,转化大肠杆菌BL21(DE3)后诱导表达.用免疫印迹法对表达蛋白进行鉴定和分析并用临床样本进行初步验证.结果 重组质粒在BL21(DE3)菌株中经IPTG诱导、SDS-PAGE和免疫印迹鉴定显示在相对分子质量(Mr) 69×103、63×103和56×103处出现清晰条带,重组质粒经双酶切鉴定,表达产物经GST标签鉴定均正确.16份呼吸道分泌物WU多瘤病毒核酸阳性血清标本和70份阴性标本免疫印迹分析表明,重组蛋白具有良好的抗原性.结论 成功构建了WU多瘤病毒衣壳蛋白VP1、VP2和VP3的表达载体,表达的重组蛋白具有良好的抗原性,为进一步研究提供了资料.

Abstract：

Objective To express the capsid proteins of WU polyomavirus(WUPyV) for research and find antigen for diagnostic value. Methods Coding sequences of capsid proteins of WU polyomavirus by PCR were cloned in prokaryotic expression vector PGEX-20T. Recombinant plasmids were transformed into E. coli BL21(DE3) and induced by IPTG for proteins expression. Recombinant proteins were identified by Western blot. Results SDS-PAGE proved that recombinant proteins showed three bands with molecular relative mass of 69×103, 63×103 and 56×103. The recombinant proteins were recognized by anti-GST McAb. The antigenicity was tested by Western blot using 16 WU polyomavirus positive and 70 negative sera. Conclusion Recombinant VP1, VP2 and VP3 expressed in E. coli can combine with WUPyV-Ab and have good antigenicity. They can be used for further research.     

儿童社区获得性肺炎血清免疫学病毒特异性抗体检测与呼吸道病毒核酸检测结果一致性分析

目的:探讨儿童社区获得性肺炎的病毒血清特异性抗体检测与呼吸道病毒核酸检测结果的一致性,以指导其临床应用。方法:109例经鼻咽拭子标本实时荧光定量PCR检测诊断为病毒感染的社区获得性肺炎患儿,采集其急性期和恢复期血清标本,采用间接免疫荧光法检测呼吸道常见病毒(呼吸道合胞病毒、腺病毒、甲型流感病毒、乙型流感病毒和副流感病毒...     

Identification of WU polyomavirus from pediatric patients with acute respiratory infections in Beijing, China

A novel polyomavirus (WU virus) has been identified in pediatric patients with acute respiratory tract infections (ARI), but its role as a respiratory pathogen has not yet been demonstrated. To investigate if WU virus is related to acute respiratory infections in infants and children in Beijing, specimens collected from 674 pediatric patients with ARI from April 2007 to May 2008 and from 202 children without ARI were used for this investigation. Common respiratory viruses were tested by virus isolation and/or antigen detection by indirect immunofluorescent assay followed by RT-PCR or PCR for other viruses associated with respiratory infections in specimens collected from patients with ARI before WU virus DNA was detected. WU virus DNA was detected by initial screening and secondary confirmation PCR for all specimens. The region encoding the VP2 gene of the virus was amplified from 17 WU-virus-positive clinical specimens, and sequence analysis was performed. Thirty-eight of 674 (5.6%) specimens from patients with ARI and 3 of 202 (1.5%) specimens from children without ARI yielded PCR products with the predicted molecular weight, using either screening or confirmation primer sets, indicating that these specimens were WU virus positive. However, more than 60% of the 38 WU-virus-positive specimens from patients with ARI were also positive for one or more respiratory viruses. The nucleotide and deduced amino acid sequences of the region encoding the VP2 gene from 17 Beijing WU viruses shared high homology (>98.5%) with sequences from GenBank and among themselves. The data indicated that WU virus in Beijing occurred 3.7 times more frequently in pediatric patients with ARI than in those without ARI (p < 0.05).     

WU polyomavirus in children with acute lower respiratory tract infections, China.

BACKGROUND: WU polyomavirus (WUPyV), a new member of the genus of Polyomavirus in the family Polyomaviridae, has been found and associated with respiratory tract infections recently. However, its clinical role and pathogenicity has not been known. OBJECTIVES: To confirm that WU polyomavirus has been found in Chinese children. STUDY DESIGN: WU polyomavirus was detected and identified using PCR methods. A total of 278 specimens of nasopharyngeal aspirate were collected, and then PCR products were sequenced directly. RESULTS: One of 278 nasopharyngeal aspirates was positive for WUPyV in one child, and the positive rate was 0.4%. The results showed that the sequences of genome, LTAg and VP2 gene was identical to the reference sequences of WU polyomavirus prototype strains. CONCLUSIONS: We confirmed that WU polyomavirus had been found and identified in the respiratory secretions in China.     

Comparison of throat swabs with sputum specimens for the detection of Chlamydia pneumoniae antigen by direct immunofluorescence.

AIM: To compare throat swabs with sputum specimens for Chlamydia pneumoniae antigen detection. METHODS: During a one year period, sputum and throat swabs from 50 patients over 15 years of age with acute or persisting lower respiratory tract infection were examined for C pneumoniae antigen by direct immunofluorescence. RESULTS: C pneumoniae antigen was detected in 18/50 patients (36.0%) from sputum, throat swab, or both. Paired sputum and throat swabs were received from 35/50 patients (70.0%). C pneumoniae antigen was detected in either or both specimens from 14/35 patients (40.0%). Of the 14 positive patients, both specimens were positive in nine (64.3%), throat swab only in four (28.6%), and sputum only in one (7.1%). Of the remaining 15 patients from whom only a single specimen was sent, a further three of eight throat swabs and one of seven sputum specimens were positive. There was no statistically significant difference between the results obtained from the two types of specimen. CONCLUSIONS: Throat swabs may be as good as sputum for the detection of C pneumoniae antigen.     

Direct detection of Mycoplasma pneumoniae antigen in clinical specimens by a monoclonal antibody immunoblot assay

Throat swabs from patients with pharyngitis and sputum specimens from patients with atypical pneumonia were tested for the presence of a Mycoplasma pneumoniae polypeptide with a molecular weight of 43,000 with the use of an M. pneumoniae species-specific monoclonal antibody in an immunoblot assay. This 43,000-dalton polypeptide was detectable in 33 of 33 throat swabs from patients with pharyngitis that were positive for M. pneumoniae by conventional culture as well as a culture-amplified enzyme immunoassay. The 43,000-dalton polypeptide was also detected in three of three M. pneumoniae culture-positive sputum specimens. It was not detected in 3 sputum specimens culture-confirmed for Legionella pneumophila, 10 sputum specimens from normal persons, or 25 throat swabs also from normal persons. This immunoblot assay could be completed within five hours and may be an alternative method for detecting M. pneumoniae antigen directly in sputum or throat swab specimens.     

Detection and discrimination of WU/KI polyomaviruses by real-time PCR with melting curve analysis

WU and KI polyomaviruses are novel viruses of the Polyomaviridae family, which have been identified recently in respiratory secretions from patients with acute respiratory tract infection. Their potential role in respiratory disease is still unclear and requires additional investigation. To facilitate further studies and diagnosis, a real-time PCR with melting curve analysis was optimized and evaluated to detect WU and KI polyomaviruses. Primers specific for the VP1 gene were designed from regions conserved among WU and KI polyomaviruses which provided amplification products of 198 and 231bp corresponding to WU and KI, respectively and thus yielded a difference in melting temperature (T(m)) between WU and KI polyomaviruses. The assay proved highly specific for WU and KI polyomaviruses as no cross amplification was detected with other respiratory viruses or human genomic DNA. The assay was also highly sensitive with a detection limit as low as 10copies/muL for both WU and KI polyomaviruses. The performance of the real-time PCR assay was evaluated in terms of amplification efficiency (92%). Finally, the assay was validated using DNA extracted from clinical respiratory specimens for WU and KI polyomaviruses and the results were confirmed by direct nucleotide sequencing. The results obtained by melting curve analysis were in perfect agreement with nucleotide sequencing. In conclusion, this method is advantageous because it is rapid, specific, sensitive, reproducible, accurate, cost-effective and thus, would be feasible and attractive for large-scale analysis aimed at investigating the clinical role of WU and KI polyomaviruses.     

Rapid Detection of Chlamydia pneumoniae by PCR-Enzyme Immunoassay

Chlamydia pneumoniae is an important human respiratory pathogen. Laboratory diagnosis of infection with this organism is difficult. To facilitate the detection of C. pneumoniae by PCR, an enzyme immunoassay (EIA) for analysis of PCR products was developed. Biotin-labeled PCR products generated from the 16S rRNA gene of C. pneumoniae were hybridized to a digoxigenin-labeled probe and then immobilized to streptavidin-coated microtiter plates. Bound PCR product-probe hybrids were detected with antidigoxigenin peroxidase conjugate and a colorimetric substrate. This EIA was as sensitive as Southern blot hybridization for the detection of PCR products and 100 times more sensitive than visualization of PCR products on agarose gels. The diagnostic value of the PCR-EIA in comparison to cell culture was assessed in throat swab specimens from children with respiratory tract infections. C. pneumoniae was isolated from only 1 of 368 specimens tested. In contrast, 15 patient specimens were repeatedly positive for C. pneumoniae by PCR and Southern analysis. All of these 15 specimens were also identified by PCR-EIA. Of the 15 specimens positive by 16S rRNA-based PCR, 13 specimens could be confirmed by omp1-based PCR or direct fluorescent-antibody assay. Results of this study demonstrate that PCR is more sensitive than cell culture for the detection of C. pneumoniae. The EIA described here is a rapid, sensitive, and simple method for detection of amplified C. pneumoniae DNA.     

The human polyomaviruses KI and WU: virological background and clinical implications

In 2007, two novel polyomaviruses KI and WU were uncovered in the respiratory secretions of children with acute respiratory symptoms. Seroepidemiological studies showed that infection by these viruses is widespread in the human population. Following these findings, different biological specimens and body compartments have been screened by real‐time PCR in the attempt to establish a pathogenetic role for KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV) in human diseases. Although both viruses have been found mainly in respiratory tract samples of immunocompromised patients, a clear causative link with the respiratory disease has not been established. Indeed, the lack of specific clinical or radiological findings, the frequent co‐detection with other respiratory pathogens, the detection in subjects without signs or symptoms of respiratory disease, and the variability of the viral loads measured did not allow drawing a definitive conclusion. Prospective studies carried out on a large sample size including both immunocompromised and immunocompetent patients with and without respiratory symptoms are needed. Standardized quantitative real‐time PCR methods, definition of a clear clinical cutoff value, timing in the collection of respiratory samples, are also crucial to understand the pathogenic role, if any, of KIPyV and WUPyV in human pathology.     

Seroepidemiology of human bocavirus in Hokkaido prefecture, Japan

A new human virus, provisionally named human bocavirus (HBoV), was discovered by Swedish researchers in 2005. A new immunofluorescence assay using Trichoplusia ni insect cells infected with a recombinant baculovirus expressing the VP1 protein of HBoV was developed, and the levels of immunoglobulin G antibody to the VP1 protein of HBoV in serum samples were measured. The overall seroprevalence rate of antibodies against the VP1 protein of HBoV in a Japanese population aged from 0 months to 41 years was 71.1% (145 of 204). The seropositive rate was lowest in the age group of 6 to 8 months and gradually increased with age. All of the children had been exposed to HBoV by the age of 6 years. A rise in titers of antibody against the VP1 protein of HBoV during the convalescent phase was observed for four patients with lower respiratory tract infections, and HBoV DNA was detected in nasopharyngeal swab and serum samples from all four patients. These results suggest that HBoV is a ubiquitous virus acquired early in life and that HBoV might play a role in the course of lower respiratory tract infections.     

Simultaneous detection and differentiation of human polyomaviruses JC and BK by a rapid and sensitive PCR-ELAHA assay and a survey of the JCV subtypes within an Australian population

Human polyomaviruses JCV and BKV can cause several clinical manifestations in immunocompromised hosts, including progressive multifocal leukoencephalopathy (PML) and haemorrhagic cystitis. Molecular detection by polymerase chain reaction (PCR) is recognised as a sensitive and specific method for detecting human polyomaviruses in clinical samples. In this study, we developed a PCR assay using a single primer pair to amplify a segment of the VP1 gene of JCV and BKV. An enzyme linked amplicon hybridisation assay (ELAHA) using species-specific biotinylated oligonucleotide probes was used to differentiate between JCV and BKV. This assay (VP1-PCR-ELAHA) was evaluated and compared to a PCR assay targeting the human polyomavirus T antigen gene (pol-PCR). DNA sequencing was used to confirm the polyomavirus species identified by the VP1-PCR-ELAHA and to determine the subtype of each JCV isolate. A total of 297 urine specimens were tested and human polyomavirus was detected in 105 specimens (35.4%) by both PCR assays. The differentiation of JCV and BKV by the VP1-PCR-ELAHA showed good agreement with the results of DNA sequencing. Further, DNA sequencing of the JCV positive specimens showed the most prevalent JCV subtype in our cohort was 2a (27%) followed by 1b (20%), 1a (15%), 2c (14%), 4 (14%) and 2b (10%). The results of this study show that the VP1-PCR-ELAHA is a sensitive, specific and rapid method for detecting and differentiating human polyomaviruses JC and BK and is highly suitable for routine use in the clinical laboratory.