诊断用丁肝抗原的基因优化及其蛋白表达、纯化和鉴定

目的 获取有生物活性的丁肝抗原蛋白,探讨其作为诊断试剂的应用价值.方法 经密码子优化,合成人工编码的丁肝抗原基因序列;以M48作为表达载体,构建带有硫氧还蛋白的重组表达质粒;在大肠埃希氏菌中经IPTG诱导表达;以亲和层析纯化并以ELISA鉴定该蛋白.结果 酶切鉴定构建的质粒正确;SDS-PAGE结果显示表达和纯化的外源蛋白与预期相对分子质量大小一致;ELISA鉴定该蛋白有与丁肝抗体特异性结合的活性.结论 成功获得有生物活性的可供诊断用的丁肝抗原蛋白,为丁肝诊断试剂的研发奠定了基础.     

荧光RT-PCR检测与ELISA检测在戊肝临床诊断效果的比较分析

目的 探讨和比较荧光RT-PCR检测与ELISA检测在戊肝临床诊断的效果.方法 从我院健康体检中心2013年1月至2016年1月的50500血清标本中随机选择100份作为研究标本.通过采用酶联免疫法对戊肝抗体的检测,然后再通过荧光RT-PCR检测法进行确诊,观察和比较两组检测方法的检查结果.结果 阳性一致率为55％,阴性一致率为100％,总一致率为75％,Kappa值为0.59(0.4＜ Kappa≤0.75),表示两者一致性一般.ELISA阳性检出率为30％,PCR阳性检出率为50％,PCR阳性检出率明显高于ELISA,数据比较差异具有统计学意义,P=0.000 ＜0.005.结论 荧光RT-PCR检测和ELISA检测在戊肝的诊断中都具有一定的检查准确度,同时荧光RT-PCR检测的阳性检出率明显高于ELISA检测.由于ELISA检测容易受到各方面因素的影响而发生漏诊的情况,因此建议对于ELISA检测出现可疑的标本,使用RT-PCR进行确诊,使更具可靠性.     

探讨三种检测方法在丙型肝炎诊断中的应用价值

目的探讨ELISA法检测丙型肝炎病毒核心抗原(HCVcAg)、病毒抗体(抗-HCV)及RT-PCR法检测丙型肝炎病毒RNA(HCV-RNA)3种方法在丙型肝炎诊断的应用价值。方法采用HCVcAg ELISA试剂盒,抗-HCV ELISA试剂盒及HCV-RNA PCR试剂盒,对临床200例疑似丙肝病毒感染的样本进行HCVcAg、抗-HCV和HCV-RNA检测。结果 HCVcAg阳性检出率为42%;HCV-RNA阳性检出率最高,为61%;抗-HCV阳性检出率为52%。Kappa检验示3种检测方法结果阳性吻合度基本一致。HCVcAg阳性检出率随着HCV病毒含量的升高而升高。结论 3种方法中,RT-PCR检测HCV-RNA仍是判断丙肝感染最准确方法。HCV核心抗原检测可以有效缩短窗口期,联合运用抗-HCV和HCVcAg或抗-HCV和HCV-RNA,能有效降低单独使用抗-HCV检测的漏检风险。HCVcAg可作为HCV抗体常规检测的补充指标,提高检出率。     

ELISA方法检测MP-IgM与冷凝集试验对小儿肺炎支原体感染诊断价值的比较

目的 通过ELISA法与冷凝集试验两种方法检测小儿肺炎支原体肺炎(MPP)患者的血清,分析两种检验方法在小儿肺炎支原体感染的诊断的价值.方法 选择本院儿科收治确诊的157例肺炎支原体感染患儿,分别采用血清ELISA和冷凝集两种检测方法,分析探讨两组阳性率.结果 ELISA法检测MP-IgM阳性有142例,阳性检出率为90.4％;冷凝集试验方法检测阳性为126例,阳性检出率为80.3％,各年龄段阳性检出率差异具有统计学意义,两种检测方法学差异具有统计学意义(P＜0.05).结论 ELISA法与冷凝集试验相比,敏感性更高,具有良好的实验室诊断价值.     

巨细胞病毒感染对细胞肾素基因表达的影响及其生物学意义

目的 探讨巨细胞病毒(cytomegalovirus,CMV)感染肾球旁细胞肾素基因表达的变化及其意义.方法 用病毒感染复数(MOI)为10、0.1和0的鼠CMV分别与鼠肾球旁细胞模型As4.1细胞共育5 d作为实验组;用紫外线灭活病毒的假感染(mock感染)对照组.RT-PCR检测感染细胞中CMV即刻早期基因1(IE1)的表达;免疫荧光观察肾素阳性细胞和肾素阳性颗粒在细胞的分布;双色免疫荧光染色观察肾素阳性颗粒是否出现在CMV阳性细胞;RT-PCR和Western blot检测肾素基因在感染细胞内的表达.结果 CMV感染As4.1细胞后出现典型的病毒空斑;病毒感染细胞CMV IE1 RT-PCR产物阳性;肾素阳性细胞集中在病毒空斑周围CMV新感染细胞区,肾素阳性荧光颗粒主要以块状和环状存在于病毒感染细胞质中;双色免疫荧光染色显示肾素阳性颗粒和CMV阳性颗粒出现在同一细胞;CMV感染细胞肾素基因的表达随病毒感染量增加而增加.结论 CMV感染并导致其宿主细胞肾素基因表达,可能涉及CMV加速心血管疾病发生发展的新机制.     

巨细胞病毒感染对细胞肾素基因表达的影响及其生物学意义

目的 探讨巨细胞病毒(cytomegalovirus,CMV)感染肾球旁细胞肾素基因表达的变化及其意义.方法 用病毒感染复数(MOI)为10、0.1和0的鼠CMV分别与鼠肾球旁细胞模型As4.1细胞共育5 d作为实验组;用紫外线灭活病毒的假感染(mock感染)对照组.RT-PCR检测感染细胞中CMV即刻早期基因1(IE1)的表达;免疫荧光观察肾素阳性细胞和肾素阳性颗粒在细胞的分布;双色免疫荧光染色观察肾素阳性颗粒是否出现在CMV阳性细胞;RT-PCR和Western blot检测肾素基因在感染细胞内的表达.结果 CMV感染As4.1细胞后出现典型的病毒空斑;病毒感染细胞CMV IE1 RT-PCR产物阳性;肾素阳性细胞集中在病毒空斑周围CMV新感染细胞区,肾素阳性荧光颗粒主要以块状和环状存在于病毒感染细胞质中;双色免疫荧光染色显示肾素阳性颗粒和CMV阳性颗粒出现在同一细胞;CMV感染细胞肾素基因的表达随病毒感染量增加而增加.结论 CMV感染并导致其宿主细胞肾素基因表达,可能涉及CMV加速心血管疾病发生发展的新机制.     

丁型肝炎病毒内蒙古株的原核表达及抗原性分析

目的获得表达量高、抗原性强的基因工程重组抗原。检测不同地区的丁肝患者血清,初步验证其抗原性及在检测不同地区丁肝血清方面的差异。方法从内蒙古某丁肝患者血清中提取丁肝病毒,经RT-PCR与PCR,使用PET43a表达质粒及HDVL-Ag5′和3′端引入His标签获得丁型肝炎病毒L-Ag重组表达质粒,转化BL21(Rosetta)宿主菌,IPTG诱导表达。表达产物经饱和硫酸胺沉淀与亲和层析柱纯化后,采用EIA竞争法分析其抗原性。结果经与ABBOTT Murex anti-Delta(total)试剂盒同步检测15份阳性和10份阴性血清,一致率100%。结论EIA检测,证明具有良好的抗原性,基因工程表达的抗原蛋白在检测不同地区丁肝血清方面未见差异,故可用于丁肝的诊断及相关研究。     

急性肝炎恢复期血清检测抗戊型肝炎病毒抗体及RNA的临床诊断意义

目的 在急性非甲-戊型肝炎患者中进一步追踪检测不同时期血清抗戊型肝炎病毒(HEV)IgG，以明确临床诊断。方法 用美国Genelabs公司和北京万泰公司抗HEV诊断试剂检测抗HEV，用PCR方法检测HEVRNA，并进行基因序列分析。结果 95例入院首次血清学诊断为急性非甲-戊型肝炎患者中，在住院后11～25d、25～35d分别测定血清抗HEV,16例血清抗HEV阳性(万泰公司)，急性期血清HEVRNA检测10例HEVRNA阳性，经核苷酸序列分析证明，其中4例为Ⅰ型HEV感染，6例为Ⅳ型HEV感染。GenekLbs诊断试剂检测12例抗HEV阳性，7例HEVRNA阳性，其中4例是HEVⅠ型病毒感染，3例是HEV Ⅳ病毒感染。结论 对非甲-戊型肝炎患者进行急性期HEV RNA检测和恢复期抗HEV检测可以进一步明确病原学诊断，在这部分患者中存在HEV不同基因型感染。可能是HEV感染漏诊的原因之一。     

晚期孕妇血清sIL-2R水平与先天性HCMV感染的相关性

目的探讨人巨细胞病毒(HCMV)活动性感染的孕妇血清可溶性白细胞介素-2受体(sIL-2R)水平与先天性HCMV感染的相关性.方法联合应用酶联免疫吸附试验(ELISA)和逆转录PCR(RT-PCR)法筛检外周血HCMV-IgM和HC-MV晚期mRNA均阳性的妊娠晚期孕妇,再用套式PCR法(Nest-PCR)检测其新生儿脐血HCMV-DNA,然后随机选择新生儿HCMV-DNA阳性34例和阴性41例作为研究对象,应用ELISA法定量检测其相应孕母外周血血清sIL-2R水平.结果其新生儿脐血CMV-DNA阳性和阴性的孕妇血清sIL-2R平均水平分别为301.01±35.14U/ml和197.75±17.51U/ml(t=2.83,P＜0.01).结论活动性HCMV感染的妊娠晚期孕妇血清sIL-2R水平可能与先天性HCMV感染的发病机制相关.     

2007-2010年河北省卢龙县婴幼儿腹泻患者A组轮状病毒感染监测

目的 了解河北省婴幼儿腹泻患者轮状病毒的感染特点及基因型别的变迁情况.方法 2007 -2010年在河北卢龙县医院和卢龙县妇幼保健院收集5岁以下腹泻住院病例1643例的粪便标本,采用酶联免疫吸附试验( ELISA)检测轮状病毒抗原,阳性标本用多重反转录-聚合酶链反应(RT-PCR)进行基因分型.结果 1643例标本中8...     

Evaluation of human immunodeficiency virus seroprevalence in population surveys using pooled sera.

The pooling of individual serum samples to determine human immunodeficiency virus (HIV) seropositivity was examined to assess whether testing pooled sera was technically feasible, cost-effective, and accurate for estimating seroprevalence in large population surveys. The sensitivities and specificities of three commercially available HIV enzyme-linked immunosorbent assay (ELISA) kits were tested using 65 serum pools of 15 individual serum samples each (975 total serum samples) at two different dilutions. With pooled sera, the Organon Teknika Bio-EnzaBead ELISA at half the dilution recommended by the manufacturer showed the best agreement with ELISA and Western blot results of individual sera. In subsequently testing 92 pools, each containing 15 individual serum samples from a population of American patients attending a sexually transmitted diseases clinic, the estimated seroprevalence was 5.27 compared with 4.93% in a test of 1,380 individual serum samples and 5.19% in a test of 4,028 individual serum samples from the same population. In an evaluation of 1,380 African patients using 10 serum samples per pool, the estimated seroprevalence was 5.79 compared with 6.16% in a test of individual sera. These results indicate that ELISA testing with pooled sera is highly sensitive and specific and appears to be a cost-effective means for estimating HIV seroprevalence in large population-based surveys.     

HEV seroprevalence in blood donors in Turkey by two commercial total anti-HEV Ab ELISA kits

Previous hepatitis E virus (HEV) seroprevalence studies in Turkey have shown high variabilities, leading to conflicting results. We aimed to re-evaluate HEV seroprevalence among blood donors in Turkey using the Wantai (Beijing, China) and the Dia.Pro (Milan, Italy) total anti-HEV antibody (Ab) enzyme-linked immunosorbent assay (ELISA) kits and compare their performances and to investigate the presence of HEV RNA in blood donors. Serum total anti-HEV antibodies were determined in a total of 2011 volunteer blood donor samples collected from different regions of Turkey (807 from Ankara, 243 from Kayseri, 284 from İzmir, 200 from Malatya, 200 from Kahramanmaraş, and 277 from Van). HEV RNA was evaluated by a real-time polymerase chain reaction in a total of 272 anti-HEV seropositive samples. The country-wide HEV seroprevalence was calculated as 11.5% (Dia.Pro) and 12.2% (Wantai) with seropositivity rates of 12.0%-12.5% in Ankara, 7.4%-8.2% in Kayseri, 14.5%-15.5% in Malatya, 8.1%-8.8% in İzmir, 15.0%-16.0% in Kahramanmaraş, and 12.6%-13.4% in Van by Dia.Pro and Wantai kits, respectively. The lowest detectable Ab concentrations were 0.16 and 0.14 units/mL WHO, for the Dia.Pro and the Wantai assays, respectively, showing no significant difference between assays. HEV RNA was not detected in any of the anti-HEV seropositive samples. Compared with previous studies, HEV was shown to have a higher overall seroprevalence in Turkey. Despite its limitation, the current study represents the most comprehensive HEV seroprevalence study in Turkey performed with two different commercial ELISA assays with high sensitivities so far. Further investigation is required to determine HEV genotypes in Turkey.     

Comparative study for the detection of antibodies to Neospora caninum in milk and sera in dairy cattle in southern Romania

The study aimed to assess the within-herd Neospora caninum exposure in dairy cattle in southern Romania, based on the detection of specific antibodies in milk and serum. A total of 104 paired samples of milk and serum were collected from four dairy farms. Individual samples were analyzed for N. caninum antibodies by ELISA: IDEXX Neospora Ab (Idx) (three farms: A, B, C; n = 60) and ID-VET Lab (Idv) (farm D; n = 44). Additionally, four pooled milk samples, one per each farm (A, B, C) and a composed one (A+B+C), were analyzed with Idx ELISA. Optimized cut-off values for milk samples were determined by receiver operating characteristic (ROC) analysis, with serum results considered as true status. The agreement was expressed by K values. The overall seroprevalence of N. caninum infection was 45% in the farms tested by Idx ELISA and 56.8% in the farm tested by Idv ELISA. A good agreement between serum and milk was obtained for both ELISA kits (K = 0.72 and 0.77, respectively). The specificity and sensitivity at optimized cut-off of S/P>0.704 for Idx and S/P%>7.966% for Idv were 100% and 70.37% for Idx and 89.47% and 88% for Idv. Testing pooled milk samples, there were identified as N. caninum positive the dairy farms with a 15% or higher within-herd seroprevalence at the cut-off value of S/P>0.51. This is the first study in Romania in which milk samples were tested to determine the N. caninum infection status in dairy farms, providing a base for further researches.     

丙型肝炎病毒核心抗原检测用于献血者筛查价值的探讨

目的应用酶联免疫吸附技术筛查献血员中丙型肝炎病毒核心抗原（HCV—cAg）和抗体（HCV—Ab），了解丙型肝炎病毒核心抗原筛查献血员应用价值。方法对我站2004年8-12月间的3972份献血者血清标本进行抗-HCV初、复检和HCV—cAg ELISA检测，将ELISA法阳性的25份血清标本，再做RT-PCR检测证实。结果3972份血清标本检测中，有10份仅初检抗-HCV阳性样本，经HCVRNA检测阳性有l份，12份仅复检抗-HCV阳性样本，经HCVRNA检测阳性有1份，HCV—cAg检测阳性有3份，经HCVRNA检测阳性有2份。结论HCV—cAg ELISA检测技术的敏感性与HCVRNA技术类似，但成本明显降低，可与HCV抗体联合检测应用献血员筛查。     

Characterization of Hepatitis Delta Virus in Sub-Saharan Africa

Hepatitis D virus (HDV) is a satellite of hepatitis B virus (HBV), and infection with this virus aggravates acute and chronic liver disease. While HBV seroprevalence is very high across sub-Saharan Africa, much less is known about HDV in the region. In this study, almost 2,300 blood serum samples from Burkina Faso (n = 1,131), Nigeria (n = 974), Chad (n = 50), and the Central African Republic (n = 118) were screened for HBV and HDV. Among 743 HBsAg-positive serum samples, 74 were positive for HDV antibodies and/or HDV RNA, with considerable differences in prevalence, ranging from <2% (pregnant women from Burkina Faso) to 50% (liver patients from Central African Republic). HDV seems to be much more common in chronic liver disease patients in the Central African Republic (CAR) than in similar cohorts in Nigeria. In a large nested mother-child cohort in Burkina Faso, the prevalence of HDV antibodies was 10 times higher in the children than in their mothers, despite similar HBsAg prevalences, excluding vertical transmission as an important route of infection. The genotyping of 16 full-length and 8 partial HDV strains revealed clade 1 (17/24) in three of the four countries, while clades 5 (5/24) and 6 (2/24) were, at least in this study, confined to Central Nigeria. On the amino acid level, almost all our clade 1 strains exhibited a serine at position 202 in the hepatitis D antigen, supporting the hypothesis of an ancient African HDV-1 subgroup. Further studies are required to understand the public health significance of the highly varied HDV prevalences in different cohorts and countries in sub-Saharan Africa.     

Inter-laboratory studies for the evaluation of ELISA kits for the detection of chloramphenicol residues in milk and muscle

The use of chloramphenicol in veterinary medicine was banned in the EU in 1994. As the Community Reference Laboratory for antibiotic residues in food of animal origin, one of our functions is to organize inter-laboratory studies. A first inter-laboratory study for the analysis of chloramphenicol (CAP) in milk by ELISA kits was organized in 2001 and a second one for the detection of CAP in pig muscle by ELISA kits in 2002. These studies were intended to allow participants to control their CAP ELISA methods when used routinely and also to compare the performances of various ELISA kits for the detection of chloramphenicol in milk (commercial or in-house kits). In 2001, 15 participants received ten randomly coded frozen milk samples (four blank samples and six spiked milk samples from 0.5 to 5.0 μg/l). In 2002, 20 participants received eight randomly coded frozen muscle samples (two blank samples and six incurred muscle samples from 2.1 to 6.5 μg/kg). They were asked to analyse each sample in triplicate with the ELISA kit of their choice. Different kits from different suppliers were used and compared in the two studies. The results of the two inter-laboratory studies on ELISA kits were satisfactory regarding qualitative results. The global rates of false compliant results of 2.2% for milk and 0.0% for pig muscle samples were lower than 5% whichever kit was used. The global rates of false non-compliant results (16.7% and 10% for milk and muscle respectively) were also satisfactory. The distribution of false non-compliant results depends on the kind of kit used and on the detection limit for milk as well as for muscle. Moreover the sample preparation was very important to avoid false non-compliant results. Finally, this study demonstrates that ELISA kits for chloramphenicol in milk and muscle globally show good repeatability and accuracy. So these kits could be considered as suitable tests for screening purposes.     

Inter-laboratory studies for the evaluation of ELISA kits for the detection of chloramphenicol residues in milk and muscle

The use of chloramphenicol in veterinary medicine was banned in the EU in 1994. As the Community Reference Laboratory for antibiotic residues in food of animal origin, one of our functions is to organize inter-laboratory studies. A first inter-laboratory study for the analysis of chloramphenicol (CAP) in milk by ELISA kits was organized in 2001 and a second one for the detection of CAP in pig muscle by ELISA kits in 2002. These studies were intended to allow participants to control their CAP ELISA methods when used routinely and also to compare the performances of various ELISA kits for the detection of chloramphenicol in milk (commercial or in-house kits). In 2001, 15 participants received ten randomly coded frozen milk samples (four blank samples and six spiked milk samples from 0.5 to 5.0 μg/l). In 2002, 20 participants received eight randomly coded frozen muscle samples (two blank samples and six incurred muscle samples from 2.1 to 6.5 μg/kg). They were asked to analyse each sample in triplicate with the ELISA kit of their choice. Different kits from different suppliers were used and compared in the two studies. The results of the two inter-laboratory studies on ELISA kits were satisfactory regarding qualitative results. The global rates of false compliant results of 2.2% for milk and 0.0% for pig muscle samples were lower than 5% whichever kit was used. The global rates of false non-compliant results (16.7% and 10% for milk and muscle respectively) were also satisfactory. The distribution of false non-compliant results depends on the kind of kit used and on the detection limit for milk as well as for muscle. Moreover the sample preparation was very important to avoid false non-compliant results. Finally, this study demonstrates that ELISA kits for chloramphenicol in milk and muscle globally show good repeatability and accuracy. So these kits could be considered as suitable tests for screening purposes.     

Evaluation of dengue IgM detection tests using sera from patients with autoimmune diseases

Three commercial dengue IgM test kits and 'in-house' IgM-capture enzyme-linked immunosorbent assay (ELISA) were examined for false positive reactions, using 49 serum samples from patients with autoimmune diseases. All the samples were found to be negative by the 'in-house' IgM-capture ELISA. Five samples were determined to be positive by the immunochromatographic test and three of the five samples were also found positive by one commercial IgM-capture ELISA kit. These results suggest that a possibility of false positive reaction should be considered when serum samples from autoimmune disease patients are tested for dengue IgM by some commercial dengue IgM test kits.     

HBsAg ELISA试剂盒筛检结果的评估

目的 评估部分国产与进口HBsAg ELISA试剂盒筛查血源的价值.方法 选用部分国产和进口HBsAg ELISA试剂,对中国生物制品检定所120份HBsAg临床科研组合血清样本及随机抽取400份东莞市无偿献血者血清标本为验证样本进行同步平行检测,以中国生物制品检定所组合血清及献血者HBsAg阳性并经中和试验证实者为金标准.结果采用四格表法计算两者对等指标并进行评价.结果 国产HBsAg ELISA试剂和进口HBsAg ELISA试剂的灵敏度分别为85.71%（72/84）和100%（84/84）;特异性分别为100%（436/436）和96.55%（421/436）;尤登指数分别为0.86、0.97;两种试剂重复合格率均为100%.结论 试剂的灵敏度以进口HBsAg ELISA试剂较好,但特异性比国产试剂差,两种试剂的重复性均好,两种试剂联合筛检献血者血样标本可提高临床输血的安全性.     

Validation of two commercial real-time RT-PCR kits for rapid and specific diagnosis of classical swine fever virus

Two real-time RT-PCR kits, developed by LSI (TaqVet CSF) and ADIAGENE (Adiavet CSF), obtained an agreement to be commercialised in France, subject to conditions, defined by the French Classical Swine Fever (CSF) National Reference Laboratory. The producers were asked to introduce an internal control to check the RNA extraction efficacy. The different criteria assessed were sensitivity, "pestivirus specificity", reproducibility and ease of handling, using 189 different samples. These samples were either CSFV inactivated strains or blood/serum/organs collected from CSFV experimentally infected pigs or naturally infected wild boars. The reproducibility of the assays was confirmed by the analysis of a batch-to-batch panel control that was used for inter-laboratory tests involving nine laboratories. The two kits were also tested for the use in mass diagnostics and the results proved the kits to be suited using pools of blood, serum and tonsils. Moreover, a field evaluation, carried out on spleen samples collected from the CSF surveillance of wild boars in an area known to be infected and from domestic pigs at a slaughterhouse, confirmed the high sensitivity and specificity of the two kits. This step-by-step evaluation procedure confirmed that the two commercial CSF real-time RT-PCR kits have a higher predictive value than the current diagnostic standard, Virus Isolation.