应用含内参的多重实时荧光RT-PCR方法快速检测登革病毒和基孔肯雅病毒

目的 建立一种登革病毒、基孔肯雅病毒并含人类基因内参检测的多重实时荧光RT-PCR方法,能在同一反应管内同时检测目前发现的所有来源的登革病毒或基孔肯雅病毒。方法 针对登革病毒3′端非编码区和基孔肯雅病毒结构蛋白E2-6K-E1区以及人体各类组织细胞中均能稳定表达的RNAse P基因,设计了3套特异性引物和探针,建立了1套能同时检测登革病毒、基孔肯雅病毒及含有人类基因检测内参的多重实时荧光RT-PCR方法,对其灵敏性和特异性进行了验证,并对临床发热病人标本进行了应用评估。结果 该方法对检测体外转录合成的登革病毒和基孔肯雅病毒RNA的灵敏性可达最低每个反应10～100拷贝,对检测登革1型病毒和基孔肯雅病毒的灵敏性分别可达最低每个反应0.1 TCID₅₀/mL和1 TCID₅₀/mL。用20株登革病毒、4株基孔肯雅病毒和日本脑炎病毒、西尼罗病毒、黄热病毒、盖塔病毒、辛德毕斯病毒各1株进行检测,方法的特异性均为100%。方法应用于189份发热病人血清标本检测,可准确地鉴定出其中登革病毒或基孔肯雅病毒核酸阳性的标本,且所有血清标本均能被内参引物和探针有效地扩增和杂交。结论 本研究建立了一种高灵敏性、高特异性且含人类基因内参检测的登革病毒和基孔肯雅病毒多重实时荧光RT-PCR检测方法,可作为登革热或基孔肯雅热病人早期快速鉴别诊断的有效工具,也可用于蚊媒携带登革病毒或基孔肯雅病毒的高通量快速筛查。     

TaqMan MGB探针实时聚合酶链反应检测登革病毒

目的建立一种敏感、特异、重复性好的登革病毒(DengueVirus,DV)鉴定方法。方法根据DV3’端非编码区基因保守序列,设计一套特异性引物和TaqManMGB探针。利用1998~2004年收集的26份登革热病人临床血清标本,15例乙脑病人血清,DV4个血清型标准毒株及23株1978~1997年DV地方流行株和相关西尼罗病毒、日本脑炎病毒、麻疹病毒、基孔肯亚病毒等毒株,同时用克隆了1型DV基因组3’端非编码区序列片段的质粒DNA作为阳性对照,检测所建立方法的特异性、敏感性。结果所建立方法的最低检测限约为每反应5个基因拷贝。用该方法检测4个血清型DV标准毒株、23株DV地方流行株和26例分离到DV的阳性血清标本,检出率为100%;用该方法检测15例乙脑病人血清、10例麻疹病人血清和西尼罗病毒、日本脑炎病毒、麻疹病毒、基孔肯亚病毒,结果均为阴性。结论新建的TaqManMGB探针检测DV方法是实验室早期诊断登革热较理想的方法。     

用3'非编码区通用引物通过RT-PCR检测登革1～4型病毒RNA

目的 　根据登革病毒 (DEN) 3 端非编码区的一段高度保守序列 ,设计登革 1～ 4型通用引物 ,采用逆转录聚合酶链反应 (RT PCR)检测登革病毒 1～ 4型RNA。方法　用C6/ 3 6细胞培养登革病毒。用热酚法提取病毒RNA ,进行RT PCR扩增 ,并对扩增产物测序。结果　DEN 2 NGC株可扩增出至少 10TCID5 0 的病毒 ,测序结果与已知序列一致。DEN 1～ 4型标准株和DEN -2 -0 4与DEN 2 4 3株均能够扩增出唯一的一条特异条带。结论　应用通用引物RT PCR法可从病毒浓度少至 10TCID5 0 的感染细胞培养液中检出DEN 2 NGC株病毒 ,并且该对通用引物对于其他 3型登革病毒亦具有很好的通用性 ,其方法的特异性和敏感性亦较强。     

病人血清中登革病毒的分离与鉴定

目的应用细胞分离法从登革热病人急性期血清中分离登革热病毒并应用免疫荧光法证实病毒的血清型。C6/36细胞长成单层后接种急性期血清,以5~7天为一代,观察细胞病变;感染后的细胞使用型特异性抗体进行免疫荧光实验证实其血清型。在10份急性期病人血清中,有6份标本成功分离出登革热I型病毒,其结果和RT-PCR等实验方法的结果一致,分离率为60%。     

Immunological evidence of Zika virus transmission in Thailand

Objective: To identify immunological evidence of Zika virus transmission in Thailand. Methods: To undertake a preliminary serosurvey of possible exposure to Zika virus, 21 serum samples from cohort of acute undifferentiated fever patients were examined for immunoreactivity to Zika, Dengue, Japanese encephalitis and Chikungunya envelope antigens by Western blot analysis. Results: Twenty of the 21 serum samples showed immunoreactivity to at least one of the antigens, with seven samples showing immunoreactivity to all antigens. Of particular note, two serum samples showed immunoreactivity only to Zika envelope antigen, with no immunoreactivity to other envelope antigens. Conclusions: This study presents the first evidence of Zika virus transmission in Thailand, although as yet the relationship between transmission and possible cases of Zika fever in Thailand requires further investigation.     

反转录环介导等温扩增技术对丙型肝炎病毒可视化分型检测

目的 应用反转录环介导等温扩增技术(RT-LAMP)可视化检测丙型肝炎病毒(HCV)1b和2a基因型,为RT-LAMP技术应用于现场或基层医院提供初步探索经验。方法 首先,收集临床阳性样本并用荧光定量PCR分型检测,把样本基本分为1型和非1型。然后分别根据HCV 1b和2a基因型设计RT-LAMP引物并优化反应条件,通过互换模板实验验证这2套引物的特异性,并通过检测稀释的模板以验证引物的灵敏度。同时用钙黄绿素进行产物显色,使HCV分型检测可视化。最后用RT-LAMP方法检测临床样本,并计算阳性率,应用配对卡方检验比较RT-LAMP和荧光定量PCR的统计学差异。结果 优化好的RT-LAMP体系的特异性好,对HCV 1b型的检测灵敏度为10³ IU/mL,2a型的检测灵敏度为10⁴ IU/mL。另外,利用钙黄绿素进行产物检测的效果和电泳结果相当。通过对临床样本分型检测,HCV 1b型样本的RT-LAMP检测结果和荧光定量PCR差异无统计学意义(P>0.05),HCV 2a型样本的RT-LAMP检测结果和荧光定量PCR差异有统计学意义(P<0.05),但是未检出的样本中有2例为HCV 2b型。结论 RT-LAMP对HCV的可视化分型检测具有较好的特异性和灵敏度,操作简便,具有在现场或基层医院的应用前景。     

Analytical and clinical performance of molecular assay used by the Brazilian public laboratory network to detect and discriminate Zika,Dengue and Chikungunya viruses in blood

In response to the Zika epidemics in Brazil, the ZDC molecular assay (Bio-Manguinhos) was developed and registered at the Brazilian Regulatory Agency of Health Surveillance - ANVISA. The circulation of Zika (ZIKV) Dengue (DENV) and Chikungunya (CHIKV) viruses and their clinical similarities are challenges to correctly diagnose these viruses. The simultaneous detection of ZIKV, DENV and CHIKV is an important tool for diagnosis and surveillance. Here, we present the analytical and clinical performance evaluation of ZDC molecular assay (Bio-Manguinhos) at the public health laboratories three years after its registration at ANVISA. The clinical performance demonstrates the ZDC molecular assay (Bio-Manguinhos) has 100% sensitivity and 100% specificity to detect and discriminate ZIKV, CHIKV, and DENV from clinical plasma samples. The ZDC molecular assay (Bio-Manguinhos) results were highly reproducible and no cross-reactivity was seen during testing with a panel of other infectious agents. In conclusion, the ZDC molecular assay (Bio-Manguinhos) is an accurate and reliable tool to monitor Zika, dengue and chikungunya infections in countries like Brazil with simultaneous circulation of the three viruses.     

Detection and subtyping of dengue 1-4 and yellow fever viruses by means of a multiplex RT-nested-PCR using degenerated primers

OBJECTIVE: Differential diagnosis of infections that cause similar diseases and may be active simultaneously in the same geographical areas is greatly needed. Dengue and yellow fever viruses (DENV and YFV) are transmitted by the same species of mosquito and both can cause haemorrhagic fever symptoms. These viruses are active mainly in regions where expensive and sophisticated technologies are not available. Our objective was to develop a simple, reliable and easy-to-perform method to detect and identify these viruses. METHODS: We slightly modified a generic RT-PCR able to detect the mentioned viruses and other members of this genus: specific primers for each one of these viruses were designed and included in the nested reaction instead of one of the generic ones. The reaction was optimized and viruses are amplified giving rise to bands of different sizes distinguishable in agarose gels. RESULTS: This test is able to detect and identify the four DENVs and YFV to a high level of sensitivity and specificity and can be used with clinical samples. This simple, reliable and easy-to-perform method able to detect and identify dengue 1-4 and YFV can be used in poor endemic countries.     

RT-LAMP与LAMP法检测结核分枝杆菌的效果比较

目的 比较RT-LAMP、LAMP、L-J法检测MTB的效果,为结核病的快速诊断提供依据。方法 用常见的非结核分枝杆菌与其他常见的呼吸道感染病菌(金黄色葡萄球菌、铜绿假单胞菌、肺炎克雷伯杆菌)检测特异性,并用酶切实验对结核分枝杆菌特异性产物进行酶切鉴定;用RT-LAMP、LAMP、L-J法检测100名结核病患者和22名来自无结核病患者痰标本中的结核分枝杆菌测试灵敏性;对浓度为1 ng/μL H37Rv标准株进行对倍比稀释用于RT-LAMP极限检测实验。结果 RT-LAMP、LAMP、L-J方法的阳性率分别为100%,92%和88%;RT-LAMP和L-J, RT-LAMP和LAMP差异均有统计学意义;RT-LAMP的灵敏度比LAMP高10倍;RT-LAMP不仅可以识别活菌,并且能够重复检测MTB的单一拷贝。结论 RT-LAMP检测效果优于LAMP及L-J,适于基层医院结核病诊断的推广和应用。     

East Central South African genotype as the causative agent in reemergence of Chikungunya outbreak in India

Chikungunya fever is an important arboviral infection prevalent throughout Africa and Southeast Asia. Recently, in 2006, it has reemerged in many parts of India, affecting more than a million persons. A detail serological, virological, and molecular investigation of this unprecedented outbreak was carried out by collecting and studying 540 samples from all the affected regions of India during this epidemic. An in-depth investigation revealed the presence of anti-Chikungunya antibodies in 68% of the samples and genomic RNA in 49% of them. In addition 32 Chikungunya viruses were isolated from 45 representative polymerase chain reaction-positive samples. The nucleotide sequences of partial E1 gene of 25 representative Chikungunya viruses were deciphered. The sequence analysis indicated that all the isolates of this epidemic belonged to the new Indian Ocean island clade of East Central South (ECS) African genotype. This study conclusively proved the genotype shift from Asian to ECS African as the major factor in the reemergence of Chikungunya in an unprecedented outbreak in India after a gap of 32 years.     

Dengue virus infection during post-epidemic period in Delhi, India

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are major public health problems in India. During the period following an epidemic, a study was carried out using virological and serological tests for confirmation of suspected cases of dengue virus infection in fever cases presenting to the All India Institute of Medical Sciences. Serum samples of suspected DF/DHF cases were processed from January to December 1997. In 37 samples from patients with fever of less than 5-day duration, received on ice, virus isolation was attempted in C6/36 clone of Aedes albopictus cell line, followed by indirect fluorescent antibody staining with monoclonal antibodies to dengue viruses 1 to 4. One hundred and forty-three serum samples from patients with more than 5 days fever were tested for dengue specific IgM antibody by either MAC-ELISA or a rapid immunochromatographic assay. Dengue virus type 1 was demonstrated by culture in 8 (21.6%) of 37 serum samples and IgM antibody could be detected in 42 (29.4%) of the 143 serum samples by the serological methods. The peak of dengue virus infection was seen from September to November 1997.     

甲型流行性感冒病毒抗原酶联免疫吸附检测试剂盒的研制及应用

目的 研制检测靶位针对甲型流行性感冒(流感)病毒核蛋白的甲型流感病毒抗原检测试剂盒,建立能检测甲型流感病毒所有亚型的方法.方法 采用双抗体夹心法检测标本中的甲型流感病毒,建立甲型流感病毒抗原ELISA方法,并对该试剂盒的灵敏性、特异性、精确性、稳定性进行测试和临床考核.结果 甲型流感病毒抗原ELISA试剂盒核蛋白检测下限为7.63 ng/Ml,灵敏度是血球凝集方法的256倍,是美国Quickdel公司胶体金产品的16倍;与乙型流感病毒、呼吸道合胞病毒、呼吸道腺病毒、副流感病毒Ⅰ/Ⅲ型、肺炎支原体、鸡新城疫病毒、鸡法氏囊病毒、鸡传染性支气管炎病毒均无交叉,特异度为100%;批内、批间变异系数(CV)值均<15%,符合国家标准;在4℃以下的稳定性可达1年,能通过37℃7 d加速试验.可检测亚型分别为H1N1、H3N2、H5N1和H9N2的甲型流感病毒.人流感病毒临床试验表明,与常规细胞培养方法比较,阳性符合率为93.44%,阴性符合率为99.31%;禽流感病毒临床试验表明,与常规细胞培养方法比较,阳性符合率为95.45%,阴性符合率为98.09%.结论 甲型流感病毒抗原ELISA试剂盒灵敏性、特异性强,可用于人甲型流感病毒和禽流感病毒感染的流行病学调查.     

Taq Man荧光定量RT-PCR快速检测甲3型流感病毒

目的建立一种特异、灵敏、快速的荧光定量RTPCR方法用于检测甲3型流感病毒核酸。方法根据GenBank登录的流感毒株序列,应用生物学软件进行序列比对,在甲3型流感病毒血凝素(HA)基因的保守区设计引物和TaqMan探针、并进行筛选。对荧光RT-PCR反应条件进行优化,检测该方法的特异性和灵敏度。并对疑似流感含漱液标本进行检测。结果该方法对甲3型流感病毒的检测有高度的特异性,对甲1型、乙型、禽流感病毒H5、SARS病毒及其他呼吸道病毒均无交叉反应,检测的灵敏度达0.01TCID50,可从疑似流感患者含漱液中直接检测流感病毒核酸,从病毒核酸提取至完成检测仅需3h左右。结论本研究建立的TaqMan荧光定量RTPCR是一种快速检测甲3型流感病毒特异、敏感的新方法。     

西尼罗病毒抗体酶联免疫吸附试验检测方法的评价

目的系统地评价血清西尼罗病毒(West Nile virus,WNV)抗体的酶联免疫吸附试验(ELISA)检测方法,为在人群和宿主动物中进行WNV感染血清流行病学调查提供技术支持。方法利用构建的包膜蛋白重组质粒(pQE-30)表达纯化西尼罗病毒包膜蛋白,以此为抗原进行ELISA检测。在对抗原包被量、酶标抗体浓度、血清稀释度进行优化的基础上,对本方法的灵敏度和特异度进行评价。结果确定最适抗原包被量为0.034μg,酶标抗体工作浓度和血清稀释度分别为1∶4 800和1∶80;批内变异和批间变异分别为6.7%和22.6%;对小鼠WNV抗体阳性血清53份、JEV抗体阳性血清48份和阴性对照血清94份进行检测,灵敏度为86.8%,特异度分别为93.8%和92.6%。结论本研究建立的ELISA方法灵敏、检测抗体特异,结果可重复,是一种有价值的血清学调查方法。