聚合酶链反应检测肺炎衣原体方法的建立与初步应用

目的 探讨聚合酶链反应（ＰＣＲ）技术在肺炎衣原体检测中的应用。方法 参照Ｃａｍｐｂｅｌｌ报道的肺炎衣原体全基因序列、Ｇ＋Ｃ比例和次级结构设计一对引物，采用ＰＣＲ法检测肺炎衣原体ＤＮＡ有临床标本中的肺炎衣原体感染。结果 经对肺炎衣原体、沙眼衣原体、大肠埃希菌、溶血性链球菌、白色念珠菌和结核分枝杆菌培养物进行ＰＣＲ扩增，结果只有肺炎衣原体出现单一４３７ｂｐ的扩增区带；敏感性试验可检测出１０ｆｇ的肺炎衣     

细菌DNA的聚合酶链反应扩增及反相杂交初步分型

目的探讨聚合酶链反应（ＰＣＲ）加反相杂交技术在细菌ＤＮＡ检测中的应用。方法以１６ＳｒＲＮＡ基因为靶序列，设计引物及寡核苷酸探针，采用ＰＣＲ法加反相杂交检测标准菌株及临床标本的细菌ＤＮＡ。结果对２４株不同标准菌株进行ＰＣＲ扩增，均出现３７１ｂｐ长度的ＤＮＡ片段，敏感性试验可检测出１０－１２ｇ的细菌ＤＮＡ，与人类基因组ＤＮＡ、真菌及病毒无交叉反应；２２例血培养阳性标本及４例脑脊液培养阳性标本均扩增出３７１ｂｐ长度ＤＮＡ条带，反相杂交法区分革兰阳性／阴性细菌与培养结果相符。结论１６ＳｒＲＮＡ基因ＰＣＲ加反相杂交技术检测细菌ＤＮＡ，具有特异、敏感、快速、准确的特点，为细菌感染的临床诊断提供了科学的依据     

套式PCR快速诊断新生儿巨细胞病毒感染

套式ＰＣＲ用于检测新生儿及随访ＣＩＤ患儿白细胞及尿中ＨＣＭＶＤＮＡ。两对引物序列取自ＨＣＭＶＩＥＡ基因区，第一对引物扩增７２１ｂｐ片段，第二对引物扩增１６７ｂｐ片段，后者穴居于前者之中，结果３３例可疑新生患儿检出ＣＭＶ感染２１例，７例随访患儿中４例尿或血中仍有ＣＭＶＤＮＡ存在。ＰＣＲ与病毒分离相比，既快速又敏感，尿标本用于ＰＣＲ检测ＣＭＶＤＮＡ较之血本具有检出率高，标本采取及处理均简便的优点。     

肺炎支原体的PCR快速检测技术在临床上的应用

采用聚合酶链反应（ＰＣＲ）技术扩增肺炎支原体特异的１４４ｂｐ ＤＮＡ片段靶基因，检测３５４例临床疑为呼吸道感染、肺炎、支气管炎病人咽拭标本，检出阳性７４例，总阳性率为２０．９％，其中儿科患者１９１例，阳性３８例，阳性率为１９．６％；老年患者８６例，阳性２０例，阳性率２３．２％；内科患者７７例，阳性１６例，阳性率２０．７％。ＰＣＲ利用体外基因复制技术，仅用１ｈ即可将极微量的ＤＮＡ样品特异地放大几百万     

多重PCR在幽门螺杆菌检测及分型中的应用

应用多重ＰＣＲ同时扩增１６ＳｒＲＮＡ和ｃａｇＡ基因来检测幽门螺杆菌感染及其分型。ＰＣＲ产物经ＤＮＡ序列测定证实为转异性扩增，敏感度为１０＾２ＣＦＵ／ｍｌ。４８株Ｈｐ菌株中，Ｉ型菌株（ｃａｇＡ＋）２６株（５４．２％）；５５０份胃粘液标本，Ｈｐ阳性（１６ＳｒＲＮＡ基因＋）２１６份（４７．５％），其中Ｉ型Ｈｐ１３９份（５３．３％）。     

应用PCR—ASO方法对广东地区非缺失型Hb H病的检测

为筛查广东地区Ｈｂ Ｈ病的基因型，用两对引物多聚酶链反应（ＰＣＲ）选择性扩增α２球蛋白基因外显子Ⅲ３１８ｂｐＤＮＡ片段和３２７ｂｐＤＮＡ片段，从７２例广东籍，经血液学确诊为Ｈｂ Ｈ病的ＤＮＡ标本中筛查出非缺失型Ｈｂ Ｈ病１０例，占Ｈｂ Ｈ病的１３．９％；缺失型Ｈｂ Ｈ病６２例，占Ｈｂ Ｈ病的８６．１％。非缺失型Ｈｂ Ｈ病α２珠蛋白基因外显子Ⅲ３１８ｂｐ ＰＣＲ产物，用两对寡核苷酸探针（Ｈｂ ＣＳ－     

聚合酶链反应检测霍乱弧菌

为快速、准确地检测霍乱弧菌，控制霍乱流行，研究建立了一种聚合酶链反应（ＰＣＲ）检测方法。根据霍乱弧菌肠毒素ＣＴ基因序列，自行设计一对特异引物，扩增片断为２９６ｂｐ，同时采用一种高效率、快速、简便的方法提取并纯化ＤＮＡ，该法能成功地检测各种样品中的产ＣＴ肠毒素Ｏ１群霍乱弧菌。应用ＰＣＲ技术和常规分离培养方法对９０９份腹泻患者粪便标本和１８份环境水样标本进行平行检测。结果表明，两种方法的检测结果一致，粪便标本阳性率为４．２％（３８／９０９）；水样标本为２２．２％（４／１８），其中１份粪便标本和１份水样标本，是经过第２次增菌培养后，检出用性，而ＰＣＲ方法未见假阳性及假阴性结果。表明ＰＣＲ方法准确、快速、灵敏，并可在２、３小时内检测出含３个菌细胞的标本。因此，该方法可广泛应用于检测各种临床、环境标本中的产ＣＴ肠毒素Ｏ１群霍乱弧菌。     

用PCR技术检测沙眼衣原体主要外膜蛋白基因序列

本实验应用ＰＣＲ技术从宫颈分泌物中直接检测沙眼衣原体。ＰＣＲ所用的引物衣原体主要外膜蛋白（ＭＯＭＰ）基因中具有特异性的稳定区域中的两条核苷酸序列，扩增片段长度为１４４ｂｐ。将经过蛋白酶Ｋ处理的标本作了模板，经变性，退火和延伸，在毛细管ＰＣＲ仪上循环６０个周期后，扩增出的衣原体特异性片段在２．０％的琼脂糖凝胶上电泳后即可被检出。在７７个标本中，１６个为ＰＣＲ阳性。与荧光单克隆抗体免疫学方法比较证明。     

应用PCR－ASO方法对广东地区非缺失型HbH病的检测

为筛查广东地区ＨｂＨ病的基因型，用两对引物多聚酶链反应（ＰＣＲ）选择性扩增α２珠蛋白基因外显子Ⅲ３１８ｂｐＤＮＡ片段和３２７ｂｐＤＮＡ片段，从７２例广东籍，经血液学确诊为ＨｂＨ病的ＤＮＡ标本中筛查出非缺失型ＨｂＨ病１０例，占ＨｂＨ病的１３．９％；缺失型ＨｂＨ病６２例，占ＨｂＨ病的８６．１％。非缺失型ＨｂＨ病α２珠蛋白基因外显子Ⅲ３１８ｂｐＰＣＲ产物，用两对寡核苷酸探针（ＨｂＣＳ－正常和Ｈｂ广西－正常）进行斑点杂交，检出ＨｂＣＳ８例，Ｈｂ广西２例。提示广东地区ＨｂＨ病以基因缺失型为主，非缺失型ＨｂＨ病基因突变大多发生在α２基因     

PCR和巢式PCR直接检测血清中HIV核酸序列

采用ＰＣＲ和巢式ＰＣＲ方法对５３例ＨＩＶ抗体阳性和阴性标本进行了检测，以扩增ＨＩＶ特异性ＤＮＡ序列，结果美国ＡｂｂｏｔｔＨＩＶ阳性血清２份，新加坡阳性血清２份，国内阳性血清２份及ＨＩＶ－１病毒培养物１份，两套ＰＣＲ扩增反应物均为阳性，对其中一套ＰＣＲ扩增的ｇａｇ基因序列进行巢式ＰＣＲ也为阳性。采自西南边境地区的２３份ＥＬＩＳＡ和ＷＢ阳性血清，各种ＰＣＲ反应均为阳性；１１份ＥＬＩＳＡ可疑阳性、ＷＢ阴性标本中，有两例血清呈ＰＣＲ阳性，探针杂交亦为阳性。而１２例ＳＩＶ、ＳＲＶ及猴血清标本ＰＣＲ反应均为阴性。上述结果表明，采用ＰＣＲ方法检测血清中ＨＩＶ核酸序列是一种很有前途的ＨＩＶ感染诊断方法。     

基因芯片检测输血传播病毒方法的实验研究

目的建立基因芯片快速检测经输血传播病毒核酸的方法,进而探讨该方法用于检测临床标本的可行性。方法通过PCR获得TTV病毒ORF1基因的DNA片段,克隆,从重组质粒扩增DNA片段,并点到玻璃载体上,制成芯片。与TTV病毒、甲型肝炎病毒、乙型肝炎病毒及戊型肝炎等病毒的PCR产物进行杂交,以检测探针的特异性。结果该基因芯片探针仅与TTV毒株的PCR产物杂交呈阳性,与对照病毒的PCR产物杂交呈阴性。敏感性试验显示,用该方法检测了27份疑似TTV临床病料,22份阳性;而用PCR法扩增TTV ORF1基因确诊为阳性的只有19份。结论利用基因芯片检测TTV的PCR产物,特异性和敏感性强,可作为TTV临床标本检测方法。     

Detection of cytomegalovirus by dot-blot DNA hybridization using probes labelled with 32P by nick translation or random hexanucleotide priming

A DNA hybridization assay for the detection of human cytomegalovirus (HCMV) DNA was developed using random hexanucleotide-primed 32P-labelled Hind III restriction fragments of HCMV DNA as probes, and compared with a DNA hybridization assay using probes labelled with 32P by nick translation. Nick-translated probes were shown to be able to detect between 1 and 10 pg of homologous DNA or the DNA of 10-50 HCMV-infected fibroblasts. Random hexanucleotide-primed DNA probes lowered these detection limits to 0.1-0.5 pg of homologous DNA or one to five HCMV-infected fibroblasts. An increase in the autoradiographic exposure time from 18 h to 4 days increased the level of detection for homologous DNA or HCMV-infected fibroblast DNA by approximately five-fold. Preliminary screening of 35 urine samples by DNA hybridization using a random hexanucleotide-primed probe correctly identified three samples positive by virus isolation in tissue culture or immediate-early nuclear antigen detection and 29 of 32 samples negative by tissue culture.     

母乳及婴儿尿液人巨细胞病毒DNA检测在婴儿人巨细胞病毒感染中的应用

目的:定量检测疑似人巨细胞病毒(HCMV)感染婴儿尿液及对应母亲乳汁中HCMV DNA,评估两者在诊断HCMV感染中的价值,并比较两者浓度之间的关系。方法:选取51例疑似HCMV感染的婴儿,收集其新鲜尿液及对应的母亲乳汁,分别用荧光定量聚合酶链式反应法(FQ-PCR)检测HCMV DNA。结果:51例疑似HCMV感染婴儿尿液中,有49例检测出HCMV DNA,阳性率为96.0%(49/51)。51份婴儿母亲乳汁中,有37份检测出HCMV DNA阳性,阳性率为72.5%(37/51)。对37例尿液与乳汁HCMV DNA均为阳性的患儿,分别对尿液与乳汁HCMV DNA浓度取对数,将两者进行相关性分析,结果显示两者之间存在一定的相关性,相关系数为0.332(P<0.05)。结论:婴儿尿液中HCMV DNA检测对于婴儿HCMV的感染具有重要的价值,同时对其母乳HCMV DNA检测,可以发现婴儿尿液和母乳HCMV DNA具有一定的相关性。     

应用基因芯片快速检测临床常见细菌

目的 应用基因芯片对临床常见的8种致病细菌进行检测.方法 选取8种临床常见的致病细菌,包括金黄色葡萄球菌、铜绿假单胞菌、肺炎克雷伯菌、大肠杆菌、奇异变形杆菌、产气肠杆菌、荧光假单胞菌、宋内志贺菌.以16S rRNA基因为目的基因,白行设计通用引物系列扩增目的片段,针对高变区域设计探针,建立基因芯片检测体系,并对所选细菌...     

HCMV感染婴儿尿液病毒载量与肝脏损伤指标的相关性分析

目的 定量检测人巨细胞病毒(HCMV)感染婴儿尿液中HCMV DNA含量,检测肝脏损伤指标,并比较尿液HCMV病毒载量与肝脏损伤指标的相关性。方法 选取HCMV感染的婴儿,收集其新鲜尿液,使用荧光定量聚合酶链式反应法(FQ-PCR)检测HCMV DNA,定量检测血清ALT,AST,ALP,GGT,T-Bil和D-Bil肝脏损伤指标,并进行阳性率统计; 将尿液HCMV DNA取对数后,分别与ALT,AST,ALP,GGT,T-Bil和D-Bil进行Spearman相关性分析。结果 444例HCMV感染婴儿尿液HCMV分布范围为<2.70～7.90; 血清ALT,AST,ALP,GGT,T-Bil和D-Bil的阳性率分别为24.8%,59.0%,95.7%,31.1%,16.7%和16.3%; 尿液HCMV DNA对数与GGT存在一定的相关性,相关系数为0.099(P<0.05),而与ALT,AST,ALP,T-Bil和D-Bil均不存在相关性。结论 HCMV感染婴儿肝损伤指标具有一定的阳性率,且尿液HCMV病毒载量与GGT具有一定的相关性,与其它指标无相关性。     

Cytomegalovirus gB genotype and clinical features in Chinese infants with congenital infections

OBJECTIVE: To investigate cytomegalovirus (CMV) glycoprotein B (gB) genotypes and clinical features in Chinese infants with congenital infections. METHODS: Urine samples were obtained from 79 infants with human CMV infection confirmed by quantitative fluorescence polymerase chain reaction (PCR). A fragment of the gB gene was amplified by nested PCR. CMV gB genotyping was carried out by restriction fragment length polymorphism, and 24 samples of the amplified DNA fragments were verified by DNA sequencing. RESULTS: The levels of CMV DNA in symptomatic and asymptomatic infants were 2.95 x 10(5) and 4.5 x 10(3) copies/ml, respectively, with a significant difference (p < 0.001). In all these cases, the most prevalent genotype was gB1 (50.63%), followed by gB3 (21.52%), gB2 (17.72%), and coinfection (10.13%); gB4 was not found. Moreover, gB1 was more prevalent in infants with liver damage (22/32) than in other symptomatic infants without liver damage (8/22, p = 0.019) or asymptomatic infants (10/25, p = 0.030). The homology of CMV gB in the 24 strains amplified as compared with the sequences of prototype strains in GenBank ranged from 97.06 to 99.64%. CONCLUSIONS: The restriction fragment length polymorphism analysis of CMV gB genotypes was definite and reliable. The gB1 genotype is the most prevalent in Chinese infants with congenital CMV disease, especially in those with liver damage, followed by genotypes gB3, gB2, and gB4.     

Lack of detection of human immunodeficiency virus type 1 DNA by polymerase chain reaction in the plasma and lymphocytes of seronegative exposed hemophiliacs

Direct detection of human immunodeficiency virus type 1 (HIV-1) DNA in serum or plasma samples has been reported in seronegative as well as seropositive individuals. An alkaline lysis procedure was adapted for polymerase chain reaction (PCR) analysis of plasma specimens. Eighty- five seronegative hemophiliacs, 52 of whom had been exposed to HIV- contaminated blood components, and 19 seronegative at-risk individuals were studied. Each sample was extracted and amplified with SK38/39 gag primers at least three times. Seventy-six samples (72%) were consistently negative for HIV-1 DNA, 24 (22%) were positive only once, and 4 (3%) were positive twice. Genomic DNA from peripheral mononuclear cells was prepared from 12 of 76 negative samples, 18 of 24 samples that were positive once, and 2 of 4 samples that were positive twice and analyzed with both gag and long terminal repeat primers. None (0/32) of these cellular DNAs were positive for HIV-1, which suggests that these seronegative exposed hemophiliacs were not latently infected with HIV-1. In contrast, all (10/10) control cells from seropositive patients were positive with both primer pairs. The detection of HIV-1 DNA in serum or plasma may be prone to a high level of false-positive PCR signals and should be interpreted with caution.     

Sample preparation methods for PCR detection of Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes on beef chuck shoulder using a single enrichment medium.

To improve the utility of the polymerase chain reaction (PCR) for food samples, methods for preparing template DNA were developed to remove PCR inhibitors. Beef chuck shoulder medallions, artificially contaminated, individually or in combination, with Escherichia coli serotype O157:H7 strain FSIS 45753-35, Salmonella typhimurium DT104 strain 13HP, or Listeria monocytogenes strain Scott A at concentrations of 10, 1 and 0.5 cfu/cm(2)were swabbed with a sponge, and the sponges were enriched for 18 h at 37 degrees C in universal pre-enrichment broth (UPB). Enriched broth cultures (EBC), cell pellets (CP), or phosphate-buffered saline-washed cell pellets (PBSCP) from enriched sponge samples were compared for detection of E. coli O157:H7, S. typhimurium DT104, or L. monocytogenes by the PCR using the BAX(TM)system. Recovery of the three organisms was effective for detection of each pathogen at initial levels of 10, 1 and 0.5 cfu/cm(2)when inoculated separately, or in combination, onto the beef samples. Use of EBC, CP, or PBSCP of sponge-swabbed samples eliminated problems associated with inhibition of the PCR by food components, time-consuming extraction of DNA, and inhibition due to large amounts of non-target DNA derived from the food. The procedure involving enrichment of sponge-swabbed beef samples in UPB followed by PCR amplification using EBC with the BAX system is the most efficient and simple method for detection of E. coli O157:H7, S. typhimurium DT104, and L. monocytogenes.     

婴幼儿轮状病毒性腹泻检测及结果分析

目的 对3 848例婴幼儿腹泻患者进行粪便轮状病毒抗原检测,分析其发病规律.方法 利用金标法快速诊断试剂盒检测婴幼儿腹泻患者粪便轮状病毒抗原,并对结果进行统计分析.结果 3 848例婴幼儿腹泻患者送检标本中检测到1 083例轮状病毒抗原阳性,阳性率28.14%;>0.6～≤2岁幼儿是轮状病毒感染的高发年龄段,检测阳性率为55.20%;轮状病毒腹泻发病的高峰期为9～12月,其次是1～3月.结论 轮状病毒是婴幼儿腹泻的主要病原体,金标法检测轮状病毒具有简单、快速、特异性高的特点.     

5岁以下腹泻婴幼儿A群轮状病毒感染调查

目的了解本社区5岁以下腹泻婴幼儿A群轮状病毒的感染情况。方法收集2011年1月至12月腹泻婴幼儿粪便标本3124份,采用胶体金法进行检测。结果 3124份粪便标本中A群轮状病毒总检出率为28.3%(883/3124),其中男性患儿检出率为29.8%(523/1756),女性患儿检出率为26.3%(360/1368)。6～24个月龄婴幼儿检出率较高,占阳性病例的71.8%(634/883)。结论 A群轮状病毒是本社区5岁以下婴幼儿腹泻病的主要病原体,6～24个月龄婴幼儿是A群轮状病毒的易感人群,以冬季11、12月份至春季1、2月份为流行高峰期。