应用多重PCR方法检测石蜡包埋组织标本中的分枝杆菌DNA

应用多重PCR方法检测并鉴别石蜡包埋组织中的结核分枝杆菌复合体与非结核分枝杆菌DNA扩增片段类型 ,为结核分枝杆菌复合体感染与非结核分枝杆菌感染的病理学诊断提供一种补充的鉴别诊断方法。应用三对具有特异性的寡核苷酸引物 ,进行多重PCR扩增。这三对引物分别对应于分枝杆菌 6 5kD表面抗原、结核分枝杆菌插入序列IS6 1 1 0及人类β 珠蛋白基因的部分序列 ,其扩增产物分别为 3 83bp、1 2 3bp和 2 6 8bp。此种多重PCR方法检测的灵敏度为 0 6pg。经多重PCR扩增后进行凝胶电泳 ,结核分枝杆菌复合体 (结核分枝杆菌、牛型结核分枝杆菌、BCG)均可见 3 83bp、1 2 3bp片段 ,而非结核分枝杆菌 (鸟、龟、瘰疬、蟾蜍、堪萨斯、胞内、耻垢分枝杆菌 )仅见 3 83bp片段 (猿猴分枝杆菌与结核分枝杆菌复合体相同 )。与上述相比 ,分枝杆菌感染的临床标本分别增加了一条 2 6 8bp片段。对 2 0 9例临床初步诊断为淋巴结结核病人的石蜡包埋组织标本进行了多重PCR检测 ,1 93例病理诊断为淋巴结结核、结核性肉芽组织、结核性肉芽肿性炎症病人的标本 ,检测结果符合结核分枝杆菌复合体感…     

猕猴结核分枝杆菌PCR检测方法的建立与初步应用

目的建立猕猴结核分枝杆菌PCR快速检测方法。方法根据GenBank中报道的人型结核分枝杆菌标准株H37RV全基因序列,针对其中致病性结核分枝杆菌所特有的保守区域ESAT-6设计一对引物进行TouchdownPCR反应,利用此方法对100份野生来源猕猴全血标本进行检测,并与传统的PPD实验和咽拭子抗酸染色实验结果作比对。结果抽取33份野生来源猕猴的外周血,提取DNA进行扩增,扩增片段经纯化、回收克隆测序后用BLAST软件进行同源性对比,与GenBank中报道的序列基本相同,检测标本中有4份（4／33）为阳性,其中3份（3／33）标本与结核菌素试验和咽拭子抗酸染色试验结果相符合。结论建立了从猴全血中直接检测猴结核分枝杆菌DNA的TouchdownPCR方法,具有敏感性和特异性高,且简便的优点。     

痰涂片标本用于结核分枝杆菌耐药性检测的研究

目的 研究抗酸染色结核分枝杆菌(简称结核杆菌)阳性痰涂片标本直接用于耐药性检测的方法。方法 对18株临床分离培养的结核杆菌用利福平进行药敏试验。分别提取菌株DNA和与之对应的痰涂片标本的菌体DNA,用聚合酶链反应(PcR)扩增ropB基因后进行固相杂交和核酸测序检测结核杆菌的耐药性。结果 18株结核杆菌中有12株对利福平耐药。经PCR扩增的ropB片段与探针杂交后,敏感菌株未发现rpoB基因的突变,自耐药菌株提取的DNA中rpoB突变体的检出率为100％(12／12),痰涂片提取DNA的检出率为91．7％(11／12)。所有耐药菌株DNA与痰涂片DNA核酸测序结果相吻合,都有rpoB基因核心区域碱基突变。结论 抗酸染色痰涂片阳性标本可直接用于检测结核杆菌利福平耐药基因rpoB突变体,是一种值得临床实验室推广使用的耐药菌诊断方法。     

猕猴巨细胞病毒(RhCMV)nested PCR检测方法的建立与初步应用

目的建立猴巨细胞(RhCMV)病毒的nested PCR检测方法,并初步应用。方法根据GenBank中报道的RhCMV全基因序列,针对其中的保守区域Rh85设计两对引物进行nested PCR反应,利用此方法对20份猕猴全血标本进行检测,将检测到的猕猴阳性标本扩增片段进行克隆测序。结果利用保守区域Rh85设计的引物可对人HCMV阳性对照进行扩增。用此方法检测的20份猕猴全血标本,出现2例阳性。其中一例扩增片段经纯化、回收克隆测序后用BLAST软件进行同源性对比,与GenBank中报道的RhCMV序列基本相同。结论建立了从猴全血中直接检测猴RhCMV病毒DNA的敏感、特异的nested PCR方法。     

人巨细胞病毒的生物素DNA探针的制备和应用

本研究用克隆的HCMV AD169株DNA片段,制备了生物素标记的DNA探针,建立了检测临床脐带血、尿标本中HCMV DNA的核酸探针杂交方法。该探针可测出100pg同源DNA,不与人胚肺细胞、Hep-2细胞DNA以及其他疱疹病毒的DNA发生反应。用核酸杂交方法检测了30份脐带血标本,有11例阳性,阳性率为33％。10例孕妇尿标本中,3例阳性,阳性率为30％。检测结果表明：我们建立的生物素标记的HCMV DNA探针的点杂交法,具有高度的特异性、敏感性,比分离病毒法更迅速,可用于HCMV感染的临床标本的病毒核酸检测。     

PCR技术检测人乳头状瘤病毒DNA

本文用一对适合人乳头状瘤病毒DNA的通用PCR引物对临床阳性和正常组织进行了PCR扩增检测分析,阳性组织均得到一条特异性的DNA扩增片段,正常组织均没有任何扩增片段。阳性组织DNA扩增片段经克隆后进行DNA序列分析,证明该扩增片段确为目标DNA扩增片段。     

反向PCR方法克隆腾冲嗜酸两面菌的分子伴侣基因*

根据已知的Sulfolobus属的分子伴侣基因,设计简并引物,用PCR的方法从腾冲嗜酸两面菌(Acidianus tengchongensis)基因组DNA中分别克隆到了分子伴侣α亚基和β亚基的约500bp的基因片段。以它们为探针进行Southern杂交,确定了合适的限制性内切酶。以确定的限制性内切酶消化的基因组DNA环化物为模板,进行反向PCR反应,引物的延伸方向由已知序列出发沿环化分子向未知区域进行,扩增产物经测序表明为α亚基和β亚基基因。根据所得序列分别设计两对引物进行PCR,测序结果     

磁珠富集法分离小黄李基因组微卫星DNA片段

将微卫星探针5′端生物素化后与链亲和素磁珠特异结合,用磁珠和探针的结合物与两端连接已知序列人工接头的中国李品种小黄李(Prunus salicinacv.Xiaohuangli)基因组DNA酶切片段杂交,以此杂交片段为模板用人工接头序列为引物进行PCR扩增,根据PCR产物测序结果设计引物作为微卫星DNA的标记引物.结果在随机挑选的36个克隆进行菌落PCR检测时,从31个阳性克隆中挑选18个克隆进行测序后获得了12条特异序列,设计的8对SSR引物均在5个中国李受试品种上获得了预期的扩增产物,其中4对引物在受试品种上表现出多态性.     

16S DNA用于结核性胸膜炎的快速诊断

目的建立聚合酶链反应—毛细管电泳（PCR-CE）的方法直接检测结核性胸膜炎患者胸水中的结核分枝杆菌,以达到快速诊断结核性胸膜炎的目的。方法在大连市结核病医院收集2006年11月至2007年2月结核性胸膜炎患者的胸水120份,所有标本都经过结核分枝杆菌抗酸染色镜检和结合菌培养,其中115份为阴性标本,5份为阳性标本。利用16S DNA集保守性和变异性于一体的特点,设计合成通用引物G1：5′-FAM-GGC GGACGG GTG AGTAA-3′,G2：5′-ROX-GGA CTG CTG CCTCCC GTA G-3′,然后将标本进行DNA提取并进行PCR扩增,扩增产物用限制性内切酶HaeⅢ消化,用毛细管电泳来检测结核分枝杆菌。结果115份阴性标本中检测出结核分枝杆菌的有19份,未检测出结核分枝杆菌的有96份,其阳性率为16.52%;5份阳性标本中检测出结核分枝杆菌的有5份,阳性率为100%。结论PCR-CE方法检测结核分枝杆菌具有快速、准确、灵敏的特点,可用于结核性胸膜炎的快速诊断。     

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。     

聚合酶链式反应检测结核杆菌的研究

以人型结核杆菌基因组DNA为模板,合成二段引物各20个碱基进行聚合酶链式反应(PCR)。经琼脂糖凝胶电泳证实,获得一条245bp扩增带。PCR检测的敏感性染色体基因组DNA为1pg,菌悬液为13个活菌／ml。在特异性试验中,人型结核杆趋,牛型结核杆菌、BCG可见此扩增带。被试的其它14种扰酸菌以及变铅青链霉菌、大肠杆菌质粒Puc19、星状诺卡氏菌、红球菌均未见该扩增带。54例肺结核痰标本3种方法检查的阳性率分别为：萋尼氏抗酸染色16．7％,培养法14．8％,PCR 37．0％。前2种检查方法分别与PCR比较,经统计学处理均有显著性差异(P<0．01)。12例非结核性肺部疾患痰标本抗酸染色和PCR均为阴性。结果表明,PCR技术是快速、敏感、特异诊断结核病的方法。     

通用引物PCR检测临床常见致病菌的实验研究

通用引物可一次性扩增18种临床常见致病菌和耐药菌株的DNA,扩增片段长度在220bp左右,18种特异性探针分别与18种标准菌株的PCR扩增产物杂交结果显示探针都具有高度特异性;5种37例经法国梅里埃API细菌鉴定系统确定的临床分离菌株进行杂交鉴定,鉴定结果与分离株一致,表明设计的探针具有高度特异性及准确性。80例临床标本分别用法国梅里埃API细菌鉴定系统及PCR杂交法进行检测,阳性率分别为(52.5%)和(67.5%),表明PCR结合寡核苷酸杂交法比传统的生物学培养法更为灵敏,值得推广。     

Occurrence of RD9 region and 500 bp fragment among clinical isolates of Mycobacterium tuberculosis and Mycobacterium bovis

The present investigation dealt with the identification of Mycobacterium tuberculosis and M. bovis by RD9 region and 500 bp fragment PCR assays. Eight M. tuberculosis and 5 M. bovis characterized and identified from 40 human sputum and 41 bovine lung specimens and 20 M. tuberculosis and 9 M. bovis strains maintained at Mycobacteria Laboratory, Indian Veterinary Research Institute were included in this study. In this way, 28 M. tuberculosis and 14 M. bovis strains and, for comparison and control purpose, M. tuberculosis H37Rv, M. bovis BCG, M. canetti, M. smegmatis, M. phlei, M. chelonae, M. kansasii, M. xenopi and M. avium were subjected to RD9 and 500 bp amplification by PCR. All M. tuberculosis strains, M. tuberculosis H37 Rv and M. canetti yielded a product of 333 bp which showed presence of RD9 region in these strains, whereas all M. bovis yielded a product of 206 bp with RD9 PCR assay. There was no ampli-fication product found in M. bovis BCG, M. xenopi, M. smegmatis, M. phlei, M. chelonae, M. kansasii, and M. avium. PCR based on 500 bp fragment showed a product of 500 bp in all M. bovis strains and M. bovis BCG. There was no amplification product of 500 bp found in M. canetti, M. smegmatis, M. phlei, M. chelonae, M. avium, M. kansasii, M. xenopi and was absent in all M. tuberculosis strains. The PCR assay results correlated 100% with the culture and biochemical results of the isolates. Our study suggested that PCR based on RD9 and 500 bp may effectively identify two closely related species of M. tuberculosis and M. bovis.     

PCR法快速检测临床标本中结核杆菌DNA

应用聚合酶链反应（ＰＣＲ）快速检测临床标本（脑脊液、胸水、腹水、血、痰液）中的结核杆菌ＤＮＡ,特异性扩增片段１２３ｂｐ,为结核杆菌的特异性重复序列ＩＳ６１１０部分基因。ＰＣＲ检测人型结核杆菌的敏感性达１０ｆｇＤＮＡ。临床标本的ＰＣＲ检测阳性率（２３．３％）明显高于抗酸染色涂片（２．９％）和细菌培养（５．７％）的阳性率（Ｐ〈０．０５）。通过设立对照系统及对扩增产物酶切分析,表明该法无假阴性结果（特异     

Rapid and simple approach for identification of Mycobacterium tuberculosis and M. bovis by detection of regulatory gene whiB7

Identification of Mycobacterium tuberculosis and M. bovis is necessary for the application of adequate drug therapy. PCR amplification is a good tool for this purpose, but choosing proper target is of a great concern. We describe a PCR assay for fast detection of M. tuberculosis and M. bovis.As a BLAST and BLASTP search we selected regulatory gene whiB7 that encodes multi-drug resistance in this bacterium. Thirty clinical isolates of M. tuberculosis were sequenced and all the mutations in gene whiB7 were detected. The best set of several pairs of primers was selected and used in comparison by rpoB gene for differentiation of M. bovis, M. avium, M. kansasii, M. phlei, M. fortuitum, M. terrae, seven non-pathogenic Mycobacterium isolates and 30 clinical isolates of M. tuberculosis.It was proved that only clinical isolates of M. tuberculosis and M. bovis have positive bands of 667 bp whiB7. Other non-tuberculous and non-pathogenic isolates did not show any positive sign. Furthermore, 667-bp PCR products of whiB7 gene were observed for ten positive sputum samples (preliminarily approved to be positive for M. tuberculosis by commercially real-time based method), but no bands were detected in 5 negative sputum samples. RpoB gene could not differentiate non-tuberculous strains and non-pathogenic isolates from pathogenic clinical isolates. We concluded that PCR amplification of the gene coding for the WhiB7 protein could be successfully used as a good tool for rapid identification of M. tuberculosis and M. bovis. We propose application of this method as a rapid and simple approach in mycobacteriological laboratories.     

Molecular detection methods developed for a systemic rickettsia-like bacterium (RLB) in Penaeus monodon (Decapoda: Crustacea)

Molecular detection methods were developed to aid in the diagnosis of a rickettsia-like bacterium (RLB) which caused severe mortalities of farm-raised Penaeus monodon in Madagascar. Using primers derived from the 16S rRNA gene of bacteria, a PCR assay was optimized to amplify this region of the genome of the RLB, using extracted DNA from infected P. monodon tissue as the template. The resulting amplified PCR product was sequenced and 2 novel primers were selected from the variable region of the gene. These primers amplified a 532 bp fragment of DNA originating from the rickettsia-infected samples. The PCR assay was optimized and tested on DNA extracted from specific pathogen-free (SPF) P. vannamei tissue and several other strains of bacteria. The PCR assay with the rickettsia-specific primers was specific for this RLB and did not amplify the other DNA samples tested. The 532 bp PCR-amplified fragment was labeled with digoxigenin (DIG) for in situ hybridization assays. This probe was tested on SPF, RLB and bacteria-infected shrimp specimens preserved in Davidson's fixative. The probe was specific for both natural and experimental rickettsial infections. Hybridization with this probe required a stringent temperature of 65 degrees C, otherwise cross-reactivity was observed with other types of bacteria.     

Development of a new, combined rapid method using phage and PCR for detection and identification of viable Mycobacterium paratuberculosis bacteria within 48 hours

The FASTPlaqueTB assay is an established diagnostic aid for the rapid detection of Mycobacterium tuberculosis from human sputum samples. Using the FASTPlaqueTB assay reagents, viable Mycobacterium avium subsp. paratuberculosis cells were detected as phage plaques in just 24 h. The bacteriophage used does not infect M. avium subsp. paratuberculosis alone, so to add specificity to this assay, a PCR-based identification method was introduced to amplify M. avium subsp. paratuberculosis-specific sequences from the DNA of the mycobacterial cell detected by the phage. To give further diagnostic information, a multiplex PCR method was developed to allow simultaneous amplification of either M. avium subsp. paratuberculosis or M. tuberculosis complex-specific sequences from plaque samples. Combining the plaque PCR technique with the phage-based detection assay allowed the rapid and specific detection of viable M. avium subsp. paratuberculosis in milk samples in just 48 h.     

PCR和分离培养同时检测儿童呼吸道感染的支原体

为了解广州市儿童呼吸道支原体感染情况,用一条共同的上游引物,二条特异性的下游引物建立的ＰＣＲ方法能同时扩增ＭＰ的６９１ｂｐ和ＭＧ的４３８ｂｐ粘附因子基因片段,但不会扩增其他支原体和细菌的ＤＮＡ。     

Standardization of in-house polymerase chain reaction for the identification of Mycobacterium tuberculosis at the reference Tropical Disease Hospital in the State of Goiás, Brazil

This study compares smear, growth in Lowenstein-Jensen medium, and in-house polymerase chain reaction (PCR) techniques for the detection of Mycobacterium tuberculosis. A total of 72 specimens from 72 patients with clinical symptoms of tuberculosis, including 70 sputum and two bronchial aspirate samples, were tested in parallel by smear, culture, and in-house PCR techniques. From these, 48 (66.6%) were negative by the 3 methods, 2 (2.8%) were smear positive and negative by culture and in-house PCR, 11 (15.3%) were both smear and culture negative, and in-house PCR positive, 7 (9.7%) were positive by the 3 methods, 2 (2.8%) were positive by smear and culture, and negative by PCR, 2 (2.8%) were positive by culture and PCR, but smear negative. After the resolution of discrepancies in PCR results, the sensitivity and specificity for in-house PCR technique to M. tuberculosis relative to the culture, were 81.8% and 81.9%, respectively. These results confirm that this method, in-house PCR, may be a sensitive and specific technique for M. tuberculosis detection, occurring in both positive and negative smear and negative cultures.