环介导等温扩增技术快速检测肉中沙门氏菌

应用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)建立了一种快速、高效、灵敏的肉中沙门氏菌的检测方法。针对沙门氏菌的属特异性基因inv A设计2对引物,对人工污染肉样以及实际肉样分别进行检测。结果表明:所建立的LAMP反应能够特异性的检测沙门氏菌,对沙门氏菌纯菌的检测灵敏度为普通PCR的100倍,可达到9.8×100CFU/m L。LAMP检测人工污染沙门氏菌肉样的检测限为9.8×101CFU/m L。因此,本实验利用LAMP建立的沙门氏菌检测方法具有快速、灵敏、特异、操作简便的特点,具有广泛发展前景。     

肠炎沙门氏菌的LAMP检测方法的建立

建立肠炎沙门氏菌(Salmonella enteritidis)的环介导等温扩增(Loop-mediated isothermal amplification,LAMP)方法,实现对肠炎沙门氏菌的快速检测.通过针对肠炎沙门氏菌血清型特异性基因lygD设计LAMP内外引物对,优化LAMP扩增反应条件,采用包括肠炎沙门氏菌在内的10种不同菌株进行LAMP引物特异性检测;通过系列梯度稀释肠炎沙门氏菌菌液进行LAMP扩增,计算检出限;并对鲜鸡蛋模拟样本进行LAMP检测.结果表明LAMP法可快速特异地检测出肠炎沙门氏菌;细菌培养液检出限为2.33×101 cfu/mL,鲜鸡蛋模拟样品为2.67×l01cfu/mL.该方法反应灵敏度高,可用于食品中肠炎沙门氏菌的快速检测.     

环介导等温扩增技术在鸭源成分检测中的研究

为了建立肉产品中鸭源成分的现场快速检测技术,根据动物种间特异性的原则,筛选出一对品种特异的PCR引物,在此引物扩增片段的基础上,设计了环介导等温扩增(LAMP)引物序列,能特异检测鸭源成分。通过条件优化实验,发现在25μL的扩增体系中,内外引物浓度比为1∶4,温度为63.5℃,MgSO4添加量为5 mM/μL,dNTPs添加量为1.75 mM/μL,Bst DNA聚合酶添加量为0.4 U/μL,甜菜碱添加量为0.25μmol/μL,LAMP反应时间为30 min时,LAMP检测体系检测效果达到最优,鸭肉DNA的检测灵敏度可达到10 pg/μL。对牛羊肉中鸭源成分比例的检测灵敏度为0.000 1%。应用该方法对上海市闵行区市场中的牛羊肉产品进行抽样检测,结果从21份样品中成功检测出5份含鸭源成分的混合肉。本研究建立的LAMP检测方法灵敏、快捷,可以实现鸭源成分的现场速测,为肉制品市场的监管提供了一种新方法。     

环介导等温扩增结合免疫层析试纸条快速检测羊肉及其制品中的鸭源成分

为实现肉及肉制品中掺假成分的快速检测,本文将环介导等温扩增技术(loop mediated isothermal amplification,LAMP)与免疫层析试纸条(immunochromatographic test strip,ICTS)相结合,建立了一套可在羊肉及其制品中特异并灵敏地检测出鸭源性成分的方法。根据鸭特异性细胞色素b(cytb)基因的6个特异性区域设计LAMP引物,其中两条内引物FIP和BIP分别使用生物素(biotin)和地高辛(digoxin)标记。使用LAMP扩增技术于65℃下扩增30 min产生生物素和地高辛标记的双链DNA产物,将扩增产生的双链DNA产物(10 μL)与90 μL上样缓冲液(PBS pH=7.4)混合均匀后使用免疫层析试纸条进行可视化检测。本研究所建立的LAMP-ICTS方法能够在40 min内特异性地检测出羊肉及其制品中的鸭源成分,且与其他肉类不存在交叉反应,检出限可达到0.01%(w/w)。市售实际样品检测结果显示,所采集的羊肉片、羊肉串样品中均有鸭源性成分,且此结果与行业标准方法(PCR-电泳)的检测结果一致。LAMP-ICTS方法具有灵敏度高、特异性好、检测速度快、对仪器的依赖低等优点,适用于基层监管部门对羊肉及其制品真伪进行快速检测。     

二重环介导等温扩增法快速检测乳粉中沙门氏菌和金黄色葡萄球菌

为建立能够同时检测乳粉中沙门氏菌和金黄色葡萄球菌的二重环介导等温扩增(loop-mediated isothermal amplification,LAMP)方法。针对沙门氏菌invA基因、金黄色葡萄球菌nuc基因保守区域设计LAMP引物,优化引物浓度,并通过熔解曲线分析判断扩增靶标来源,建立同时检测沙门氏菌和金黄色葡萄球菌的二重LAMP检测方法。结果表明,当沙门氏菌与金黄色葡萄球菌引物浓度比为3∶1时,建立的二重检测体系扩增效率最佳;该方法特异性强、灵敏度高,对6株目标菌株和9株非目标菌株进行检测,未产生任何假阳性和假阴性结果,对2种食源性致病菌的检测灵敏度均达到102 fg/μL;根据熔解曲线中的退火温度可准确判断目标菌株,实现不同菌株的有效区分。建立的二重LAMP方法可用于乳制品企业大规模乳粉样品中沙门氏菌和金黄色葡萄球菌的现场快速筛查。     

环介导等温扩增法快速检测牛羊肉中的掺杂肉

面对肉制品掺假突发事件频发的现状,对动物源性成分快检方法需求迫切。在等温扩增方法基础上,开展了肉制品掺假鉴定方法研究。以猪、鸡、鸭线粒体细胞色素b基因为目的序列,采用软件Primer Explorer Version5,通过序列比对设计并筛选环介导等温扩增(Loop-mediated isothermal amplification, LAMP)的特异性扩增引物。通过反应体系优化建立猪、鸡、鸭源性成分的环介导等温扩增技术分析方法,对常见9种动物源性成分进行特异性分析,检出限达到0.001 ng/μL,高浓度牛、羊DNA不影响方法检出限。通过分析模板脱氧核糖核酸(Deoxyribonucleic acid, DNA)浓度与反应循环数的关系,建立牛羊肉产品中,阈值为1%的猪、鸡、鸭掺杂成分的LAMP快速检测方法,分析时间36 min。采用该方法对深加工模拟掺杂肉样本分析结果与现行国家标准方法结果一致。研究可为肉制品原材料、市售生鲜肉及加工肉制品的肉成分快速筛查提供解决途径。     

环介导等温核酸扩增技术快速检测食物中的大肠杆菌O157

建立了环介导等温核酸扩增技术(LAMP)检测食源大肠杆菌O157,并对该方法的灵敏度和特异性进行了评价。分别针对大肠杆菌O157三个特异基因rfbE,stx1和stx2的8个独立靶区域设计了外引物、内引物和环引物进行LAMP扩增检测,同时将检测结果与PCR方法做比较。研究结果表明,rfbE,stx1和stx2基因的LAMP方法检测限分别为100,100和10 fg DNA/管,灵敏度是PCR方法的10倍以上;将建立的环介导等温扩增法用于417株食物分离的大肠杆菌的检测,发现LAMP检测rfbE,stx1和stx2基因的灵敏度分别为100%,95.3%和96.3%,对3个靶基因的阴性预测率分别为100%,96.7%和97.1%,特异性和阳性预测率均为100%。结果表明,该方法用于大肠杆菌O157的检测具有特异性强、灵敏度高、操作简便的优越性,在食品安全检测方面具有良好的实际应用前景。     

食品过敏原羽扇豆成分的环介导等温扩增检测方法

目的建立食品过敏原羽扇豆成分的环介导等温扩增检测方法(loop-mediated isothermal amplification,LAMP)。方法根据羽扇豆的ITS基因设计羽扇豆的特异性引物,进行特异度、灵敏度、稳定性测试,建立LAMP检测方法。结果本文建立的食品过敏原羽扇豆成分LAMP检测方法能有效对羽扇豆成分进行快速检测,具有较强的特异度和稳定性,灵敏度可达0.001%(w:w)。结论该方法特异度强、灵敏度高,可以快速、准确检测食品中过敏原羽扇豆成分。     

DNA环介导恒温扩增技术速检测结核分枝杆菌的研究

DNA环介导等恒扩增(koop-mediated isothermal amplification,LAMP)技术是一种特异、灵敏、快速的新型基因检测技术,其检测结果可以通过加入核酸燃料SYBR Green l进行肉眼观察,也可以通过琼脂糖凝胶电泳进行观察.本文以结核分支杆菌(M.TB)作为研究对象,设计了4种LAMP引物以特异地识别结核分支杆菌中gyrB基因的六个特殊区域,着重于利用LAMP技术在几种常见的致病分支杆菌中能快速、特异地检测出结核分支杆菌.实验结果表明,LAMP技术能在恒温(63℃)条件下,1 h内检测出结核分枝杆茵,分别对7株非结核分枝杆茵进行检测,只有一株偶发分支杆菌得到了阳性的结果.说明该技术有望应用于畜牧业中肉制品或乳制品中结核分支杆菌的检测.     

PCR鉴定鸵鸟肉方法的建立与应用

建立一种快速准确鉴定鸵鸟肉的方法。根据鸵鸟特异基因(NCBI序列号:AB254879)设计引物,运用PCR技术扩增鸵鸟特异基因,并验证方法的特异性和灵敏度。所设计的引物特异性良好,鸵鸟肉DNA扩增后产生112 bp的特异性条带,而其他肉类未见该特异性条带;该方法在核酸水平检出限为0.01 ng,样品水平检出限为0.1%。该方法快速准确、具有较高的特异性和灵敏度,可为鸵鸟肉鉴别真假提供技术支持。     

Loop‐Mediated Isothermal Amplification (LAMP): A Rapid and Sensitive Tool for Quality Assessment of Meat Products

Loop‐mediated isothermal amplification (LAMP) is a novel method that amplifies target nucleic acids under isothermal conditions. It is a rapid, specific, and sensitive method, which does not require costly thermal cyclers for the detection of nucleic acids. Thus, it is suitable for on‐site detection assays under low‐resource settings. It can also be integrated on compact lab‐on‐a‐chip devices for the development of micro‐total analysis systems. This review discusses LAMP‐based methods, as well as LAMP‐based centrifugal, microfluidic, and other fluid‐handling devices, which have been developed for the assessment of meat quality parameters that are related to the presence or absence of nucleic acids, for example, animal species identification and microbiological quality. Advances in improving the rapidity, specificity, and sensitivity of LAMP techniques for the assessment of these meat quality parameters are also discussed in this review.     

副溶血弧菌tdh基因LAMP检测技术的建立

环等温扩增技术(Loop-mediated isothermal amplification,LAMP)是一种在等温条件下高特异性、高效、快速地扩增靶基因的DNA扩增技术。根据副溶血弧菌特异性的毒力基因tdh保守序列,本文设计1套特异性引物对该基因进行环等温扩增,同时对反应条件进行优化,建立携带tdh基因的致病性副溶血弧菌的LAMP快速检测技术。结果表明,LAMP最适反应在60.8℃恒温、45min内完成,与其它常见的细菌无交叉反应。LAMP方法的细菌DNA最低检出限为35.5fg/反应管,灵敏度较PCR方法高10倍。对扇贝样品中分离的菌株的检测表明,LAMP方法对检测致病性副溶血弧菌具有良好的可靠性。     

食品中单核细胞增生李斯特菌DNA环介导恒温扩增快速检测方法的建立

基于单核细胞增生李斯特菌胞壁质水解酶iap基因,设计两对特异性引物,利用DNA环介导恒温扩增(loop-mediated isothermal amplification,LAMP)技术,以扩增副产物焦磷酸镁实时浊度为判定标准,建立食品中单核细胞增生李斯特菌LAMP快速检测方法。结果显示,本LAMP方法特异性强,经过对29株细菌进行检测,所试单核细胞增生李斯特菌均为LAMP阳性,其他菌株为阴性;本LAMP方法对单核细胞增生李斯特菌纯培养菌的检测灵敏度为8CFU/管,对污染食品中单核细胞增生李斯特菌的检测灵敏度为12CFU/管。本研究建立的LAMP检测方法简便快速、结果判断直观。     

Rapid Detection of Salmonella enterica Subspecies enterica serovar Typhimurium by Loop Mediated Isothermal Amplification (LAMP) Test From Field Chicken Meat Samples

Considering the importance of Salmonella enterica subsp. enterica serovar Typhimurium in the foodborne diseases, a Typhimurium specific loop mediated isothermal amplification (LAMP) test was standardized for its rapid detection in chicken meat. The Optimum results were obtained at 64^oC and 70 min temperature-time combination. The sensitivity of LAMP and PCR were compared with serial 10-fold dilution of the 100 ng of DNA. The LAMP test detected 2 pg DNA per reaction tube, whereas PCR detected 200 pg DNA per reaction. Therefore, the LAMP test was considered 100 times more sensitive than the PCR. The specificity of LAMP and PCR analyzed with six different isolates of non-Salmonella and 22 serovars of non-Typhimurium. None of these isolates were found positive by both LAMP and PCR. Twenty-eight pure isolates of Salmonella Typhimurium from diverse sources were also examined by Typhimurium specific LAMP and were all found positive. Two-hundred twenty-five field chicken meat samples were screened by cultural, PCR, and LAMP methods. The LAMP and PCR tests were performed by using DNA isolated from 8 h and 18 h enrichment samples, respectively. Typhimurium specific LAMP was shown to be in 100% correlated with cultural and PCR methods. However, LAMP test delivered the results within 26 h without sophisticated equipment while PCR and cultural methods took 48 h and 6 d, respectively. The LAMP test developed in this study has potential to detect and as well as differentiate S. Typhimurium from other Salmonella serovars.     

环介导恒温扩增方法快速检测乳中单增李斯特菌

建立了一种快速检测灭菌乳中单增李斯特菌的环介导恒温扩增(Loop-Mediated Isothermal Amplification,LAMP)方法。以hlyA基因作为靶基因,对人工污染乳中单增李斯特菌进行了LAMP方法的灵敏度试验,同时与PCR方法进行比较。并对单增李斯特菌和7种其他乳中常见致病菌进行了LAMP检测,以验证该方法的特异性。结果表明,LAMP检测单增李斯特菌的特异性强,检出限为42 mL-1,其灵敏度比普通PCR高10倍。并且检测时间比PCR更短,在1.5 h内即可完成扩增反应。此方法快速、特异、简单、灵敏,具有较高的推广价值。     

Isolation and Detection of Extended Spectrum β‐Lactamase (ESBL)‐Producing Enterobacteriaceae from Meat using Chromogenic Agars and Isothermal Loop‐Mediated Amplification (LAMP) Assays

The aim of this work was to develop a molecular method using loop‐mediated isothermal amplification (LAMP) for detection of extended spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae from meat, and to compare it with different isolation agars and microarrays. LAMP assays were developed for CTX‐M groups 1, 2, and 9 and OXA‐10‐like genes. Chicken, lamb, beef, pork, and turkey samples were spiked with 10, 100, and 1,000 cfu/gram using 8 strains of ESBL‐producing Enterobacteriaceae (CTX‐M sequence types 1, 2, 3, 14, 15, OXA‐11, SHV‐2, TEM‐52) +/– a mix of competitor organisms. Samples were enriched overnight in buffered peptone water (BPW) +/– antibacterials before plating to CHROMagar CTX, OXOID ESBL Brilliance agar, and MacConkey agar with 1 mg/L cefotaxime. Selected BPW broths were also tested using LAMP assays, microarrays and using cefpodoxime discs on agar. For isolation/detection of ESBL producers from beef, pork, lamb, and turkey spiked with 10 or 100 cfu/gram ESBL (natural flora only), all agars and the LAMP assays showed 100% sensitivity and specificity for ESBL spike strains. For chicken samples, both LAMP and chromogenic agars showed improved sensitivity and specificity for isolation of ESBLs compared with MacConkey agar, particularly with competitor bacteria added. In comparison, the cefpodoxime disc method and microarray showed reduced sensitivity.     

叠氮溴化丙锭-羟基萘酚蓝-环介导等温扩增法检测畜禽肉中单核细胞李斯特菌

将叠氮溴化丙锭（propidium monoazide,PMA）、羟基萘酚蓝（hydroxynaphthol blue,HNB）与环介导等温扩增（loop-mediated isothermal amplification,LAMP）技术相结合,建立一种可视化PMA-HNB-LAMP方法快速检测畜禽肉中单核细胞李斯特菌（Listeria monocytogenes）。结果表明,当PMA终质量浓度为5.0 μg/mL、孵育和曝光时间均为15 min时,可有效抑制105 CFU/mL的单核细胞李斯特菌死菌DNA的聚合酶链式反应扩增,而对活菌DNA的扩增不具有抑制作用。LAMP反应体系中HNB终浓度为210 μmol/L时,检测显色结果肉眼可见。该方法的纯菌液灵敏度为2.4×102 CFU/mL,人工污染肉制品的检出限为2.3×104 CFU/ mL。分别采用国标法、PMA-HNB-LAMP法和HNB-LAMP法检测20 份市售畜禽肉样,3 种方法的单核细胞李斯特菌检出率分别为5%、10%和20%。PMA-HNB-LAMP法在一定程度上可解决LAMP法的假阳性问题,并且具有操作简单、可视性强的优点。     

环介导等温扩增法快速检测耐甲氧西林金黄色葡萄球菌

建立一种应用环介导等温扩增(loop-mediated isothermal amplification,LAMP)方法快速检测耐甲氧西林金黄色葡萄球菌(methicillin-resistan Staphylococcus aureus,MRSA)中mecA和spa基因的检测方法。以金葡菌和其他相关菌种为试验对象,分别用聚合酶链式反应(ploymerase chain reaction,PCR)和LAMP方法检测mecA和spa基因。结果表明：LAMP法在64℃等温条件下可在60min内成功扩增基因,且与传统PCR方法结果相同;通过琼脂糖凝胶电泳可知,LAMP对mecA和spa基因的检测限分别为每菌管102个和10个细胞;肉眼可检测到的mecA和spa基因的检测限分别为每菌管103个和10个细胞;然后用LAMP法检测人工污染原料乳样本中MRSA,用LAMP法检测原料乳中的mecA和spa基因与PCR方法显示出相同的结果。LAMP方法可快速检测mecA和spa基因,此方法可应用于原料乳中MRSA的检测。     

Sensitive and rapid detection of Alicyclobacillus acidoterrestris using loop-mediated isothermal amplification

BACKGROUND: A loop‐mediated isothermal amplification (LAMP) assay was developed for the rapid detection (within 2 h) of Alicyclobacillus acidoterrestris. The assay detected the species‐specific DNA sequence of the 16S–23S rRNA internal transcribed spacer. RESULTS: The eight strains of A. acidoterrestris were successfully amplified, but six strains of other bacillus Acidocaldarius and 13 bacterial species other than bacillus Acidocaldarius were not. The sensitivity of the LAMP assay was at 4.50 × 10^?2 cfu per tube. This sensitivity is greater than that obtained by polymerase chain reaction (PCR) assay. The LAMP assay was examined further for its ability to detect A. acidoterrestris in juice samples. The results were compared with those of conventional PCR detection. CONCLUSION: Results indicate that the proposed LAMP assay is a rapid, specific and sensitive method for detecting A. acidoterrestris. As the amplification has been conducted under isothermal conditions, only a water bath or heating block is needed to maintain the required temperature. Thus, the method can be generalised and popularised easily in the future. Copyright © 2011 Society of Chemical Industry