实时荧光PCR检测沙门菌特异基因

目的：建立一种灵敏、快速检测沙门菌的实时荧光PCR方法.方法：针对沙门菌特异性基因invA设计引物、探针,在实时荧光PCR仪上进行扩增、检测和结果分析.结果：应用该实时荧光PCR方法,30株沙门菌检测结果均为阳性,19株非沙门菌结果均为阴性,96个肛门拭子样本增菌前后的PCR结果一致;检测灵敏度达到4 cfu/test,定量结果与培养计数无显著差异.结论：该方法检测沙门菌具有灵敏度高、快速方便的特点,且可用于定量检测.     

伤寒和甲型副伤寒沙门菌复合PCR检测

目的 建立用于快速和特异检测伤寒沙门菌和甲型副伤寒沙门菌的复合PCR方法.方法 根据rfbS、rfbE、fliC和vi基因序列设计4对PCR引物,对54株沙门菌和其他菌属的菌株进行复合PCR检测.结果 采用所建立的复合PCR方法可分别检测到伤寒和甲型副伤寒沙门菌的3条和2条特异性条带带型,可与其他菌株带型准确分开.结论 本研究建立的复合PCR方法可用于检测伤寒沙门菌和甲型副伤寒沙门菌.     

PCR快速检测甲型副伤寒沙门菌鞭毛抗原H-a研究

目的研究快速、特异、灵敏的检测甲型副伤寒沙门菌鞭毛特异相H-a的PCR法.方法选择甲型副伤寒沙门菌鞭毛抗原H-a基因的特异引物进行PCR扩增,检测甲型副伤寒沙门菌标准菌株和我省不同地区上送的57株甲型副伤寒沙门菌以及非甲型副伤寒沙门菌的其它菌株;将甲型副伤寒沙门菌标准菌株按10-1～10-9稀释后扩增比较PCR的检测灵敏度.结果所有甲型副伤寒沙门菌均在329bp处出现甲型副伤寒沙门菌鞭毛抗原基因产物,非甲型副伤寒沙门菌株PCR结果均为阴性;PCR检测下限为103cfu/ml.结论 PCR比传统细菌检测方法更特异、快速、灵敏、简便,为临床诊断、实验室筛查以及流行病学快速查源、溯源提供了新的手段.     

食品中沙门菌变性高效液相色谱检测技术的研究与方法建立

目的:应用PCR结合变性高效液相色谱(DHPLC)技术建立食品中沙门菌的快速检测方法.方法:根据沙门菌fimY基因序列的特点设计特异性引物,PCR扩增的产物经DHPLC技术进行快速检测.以沙门菌等89株参考菌株做特异性检测;沙门菌液体培养物稀释成不同梯度,做灵敏度检测.结果:试验结果表明该方法有很好的特异性,而其它非沙门菌均为阴性.该方法灵敏度较高,检测低限可达到45 cfu/ml.结论:该方法可以快速、准确检测食品中沙门菌,是食品中致病菌检测的新技术和新方法.     

应用多重PCR检测食品中的沙门菌

目的 建立快速检测食品中沙门菌的多重PCR方法. 方法应用软件设计4对沙门菌群特异引物,优化多重PCR扩增条件与样品处理方法,分别对61株沙门菌、14株非沙门菌及模拟标本进行检测,观察方法的特异性、敏感性和可行性. 结果建立的多重PCR检测所有的沙门菌均能扩出清晰、特异的预期条带,而非沙门菌均未检出;每反应的灵敏度平均为100 cfu.对食品中人工污染的沙门菌的检测,最低检测量是10 cfu,检测时间为8～9 h,与培养法比较,阳性符合率100%;对市售的481份禽制品进行检测,阳性结果12份,而细菌培养法检测阳性结果为10份. 结论多重PCR检测沙门菌敏感、特异、省时、省力,适用于沙门菌快速检测.     

Real-Time PCR探针法检测食物中毒中沙门菌方法建立及应用

目的:建立食物中毒中沙门菌Real-Time PCR检测方法并将其应用。方法:选取沙门菌侵袭蛋白A基因(in-vA)进行引物和探针设计,并对反应条件不断优化,进行灵敏度和特异度测试,建立检测沙门菌的Real-Time PCR方法。结果:DNA灵敏度检测沙门菌达到56 fg/PCR体系,菌液灵敏度检测沙门菌达到9 CFU/ml,特异度100%。用建立的方法对四起食物中毒、2000份健康从业人员体检肛拭样品、80份食品监测样品进行了检测,共检出沙门菌15株。结论:该方法具有高灵敏性和高特异性的特点,可以应用在沙门菌引起的食物中毒的快速检测中。     

多种方法同步检测海产品中甲型副伤寒沙门菌的应用

目的：为查找食源性甲型副伤寒的病因,提高检出率.方法：采用国标法、mini VIDAS仪器法和PCR 3种方法同步检测11种生吃、半生吃海产品中甲型副伤寒沙门菌.检出菌株用VITEK32全自动微生物分析系统鉴定以及血清分型.结果：mini VIDAS仪器法和PCR 2种方法从1份牡蛎样品中检测出甲型副伤寒沙门菌,检出率为0.73%.结论：多种方法同步检测有利于提高生吃、半生吃海产品中甲型副伤寒沙门菌和沙门菌的检出率.用mini VIDAS或/和PCR过筛检测,具有简便快捷、灵敏度高的特点,阳性时再用国标法分离,可及时获得菌株,以提高检测工作效率,值得应用,尤其适用于杂菌量较多、目标菌易被掩盖以及不适宜甲型副伤寒沙门菌和其它沙门菌生长的样品.     

食品中沙门菌特异性二重聚合酶链反应检测方法的研究

目的建立二重聚合酶链反应(PCR)方法快速检测食品中的沙门菌(Salmonella spp.)。方法以沙门菌特异性基因invA、hilA为靶基因,选择2对引物对16株沙门菌和24株非沙门菌进行扩增,验证二重PCR的特异性。梯度稀释DNA,以不同稀释度的DNA PCR扩增。在猪肉中以不同菌量人工污染,不同增菌时间培养,提取DNA进行PCR扩增。应用该方法检测实际样品。结果以invA、hilA为靶基因的两对引物对沙门菌的检出均有很好的特异性,PCR能检出0.1332pg的沙门菌DNA,人工污染猪肉的检测限为2.5cfu/ml。本研究共检测了53份食品样品,有21份检出了沙门菌。结论建立了适用于肉类、水产品及蛋糕等食品中的沙门菌检测的快速、灵敏、特异的二重PCR方法。     

改良分子信标-实时荧光PCR同时检测猪霍乱沙门菌和丙型副伤寒沙门菌

目的 建立猪霍乱沙门菌和丙型副伤寒沙门菌的实时荧光PCR快速检测方法,应用于食品和食物中毒病人标本的猪霍乱沙门菌检测以及沙门菌属C群的鉴别诊断.方法 根据GenBank公布的猪霍乱沙门菌和丙型副伤寒沙门菌的保守序列(CP000857.1),设计引物和改良分子信标探针,优化PCR程序和PCR成分,以11种细菌为对照,建立...     

实时荧光定量PCR检测沙门菌方法的实验研究

目的:建立沙门菌实时荧光定量PCR快速检测方法,探讨沙门菌在食源性感染快速诊断中的应用价值。方法:采用沙门菌fimY基因序列设计特异引物和探针,建立实时荧光实时定量PCR技术检测沙门菌的检测方法。通过特异性、敏感性、稳定性和重复性,以验证方法的可行性。结果:成功构建了沙门菌重组质粒标准品,为方法学建立奠定基础;通过特异性、敏感性、稳定性和重复性验证,结果表明具有较好的特异性,最低检测限为103拷贝/ml,相当于100 cfu/ml的菌细胞,并有良好的稳定性和重复性。结论:沙门菌实时荧光定量PCR检测方法的建立,不仅为食源性沙门菌污染的快速检测提供依据,而且还可直接用于临床粪便标本检测。     

PCR检测沙门菌hilA基因的方法研究

目的:利用PCR技术,建立特异性引物PCR快速检测沙门菌的方法。方法:设计沙门菌h ilA基因的特异性引物,优化PCR反应条件,对沙门菌和非沙门菌进行特异性引物的PCR扩增,鉴定沙门菌。结果:所检测沙门菌株和模拟样品均出现特异性扩增条带,结果与实际相符。结论:该方法具有简单、迅速、特异性好和敏感性高的特点。     

应用PCR法检测副溶血性弧菌

目的 研究副溶血性弧菌的PCR检测方法。方法 引物选择副溶血性弧菌耐热溶血素（TDH）上的基因，应用PCR法，检测副溶血性弧菌。结果 PCR能检测经选择性增菌液培养的副溶血性弧菌，扩增片段在430bp：结论 应用PCR检测副溶血性弧菌，具有快速、特异、灵敏和简便的特点。     

PCR和毛细管电泳技术检测沙门氏菌等5种病原菌的方法研究

目的采用多重PCR技术检测结合毛细管电泳成像技术建立快速检测沙门氏菌、志贺氏菌、副溶血性弧菌金黄色葡萄球菌和大肠杆菌O157的方法。方法根据沙门氏菌hilA基因、志贺氏菌ipaH基因、副溶血性弧菌TDH基因、金黄色葡萄球菌的pSa-442 Sau3AI fragment基因及大肠杆菌O157的rfbE基因设计异性特PCR引物,被检样品经4 h振荡培养后金属浴裂解制备DNA模板,使用全自动毛细管电泳核酸检测系统分析PCR扩增产物。结果在580 bp、423bp、257 bp、245 bp和194 bp处分别出现预期的特异性DNA条带,且无非特异扩增条带出现。敏感性试验显示在模拟标本中的检测灵敏度,沙门氏菌为101-2cfu/ml、志贺氏菌为101cfu/ml、副溶血性弧菌为102cfu/ml、金黄色葡萄球菌为102cfu/ml、大肠杆菌O157为101cfu/ml。结论该方法操作方便、特异性和灵敏度高、分辨率高,可同时完成5种病原菌的检测,在公共卫生突发事件中具有实用价值。     

API20E、PCR方法在沙门菌鉴定中的应用

为了评价API 20E试条、PCR方法在沙门菌鉴定中的应用，本研究利用API 20E、PcR方法对54株疑似沙门菌进行鉴定，利用常规生化和血清学方法对鉴定结果进行确认。结果发现API20E、PCR方法与常规鉴定方法的结果一致，51株为沙门菌，3株非沙门菌（1株为柠檬酸杆菌，2株为河生肠杆菌）。API20E、PCR方法具有简便、特异、敏感的特点，可适用于沙门菌鉴定。     

合肥市屠宰生猪肉样沙门菌的PCR快速检测

目的:了解合肥市屠宰生猪肉样中沙门菌的污染状况。方法:应用聚合酶链式反应(polym erase chain reaction,PCR)对200份生猪肉样进行沙门菌的快速检测,并与常规法检测结果以及国内其他11个城市生猪肉样沙门菌的检出率作比较分析。结果:200份生猪肉样中沙门菌检出率为20%(40/200),污染率处于较高水平,而常规法的检出率为13%(26/200)。结论:合肥市生猪肉样中沙门菌的污染状况较为严重,存在发生食源性沙门菌病的潜在危险,PCR技术对沙门菌检测时间仅需2 d,与常规法相比,快速、简便、准确的优势特点使其成为调查食源性沙门菌的有用工具。     

A real-time multiplex SYBR Green I polymerase chain reaction assay for rapid screening of salmonella serotypes prevalent in the European Union

A two-step real-time SYBR Green I multiplex polymerase chain reaction (PCR) assay with melting curve analysis was developed for rapid detection of 19 Salmonella serotypes frequently encountered in humans, animals, and animal-associated meat products within the European Union. The first-step single-tube reaction (Multiplex PCR I), consisting of five primer pairs, classified an initial test panel of eight Salmonella serotypes into five groups on the basis of characteristic amplicon melting temperatures produced by each strain. Following designation into groups, two subsequent triplex reactions (Multiplex PCR II-G1 and II-G3) allowed for further identification of five Salmonella serotypes by their melting peak temperatures. Primers for serotype differentiation were designed to target the genes encoding either phase 1 and 2 flagellar antigens fliC and fljB or unique serotype-specific loci. In addition, the assay simultaneously screened for the presence of the ampicilin-amoxicillin, chloramphenicol-florfenicol, streptomycin-spectinomycin, sulfanomides, and tetracycline (ACSSuT)-type multidrug resistance pattern, indicated by the floR gene, and for the Salmonella virulence plasmid encoded by the svp operon in Salmonella serotype Typhimurium. The established multiplex assays were successfully tested on 97 isolates, comprising 37 distinct Salmonella serotypes and 12 non-Salmonella strains. The two-step assay correctly detected 19 of 37 Salmonella serotypes and all non-Salmonella strains produced negative results. Of the 19 serotypes detected in the assays, 7 serotypes, including Salmonella serotypes Ohio, Goldcoast, Livingstone, Kedougou, Enteritidis, Kentucky, ACSSuT-type Salmonella serotype Typhimurium DT104 and DT104b, as well as non-ACSSuT-type Salmonella serotype Typhimurium strains, were definitively identified. The developed multiplex real-time SYBR Green I PCR assay represents a more rapid and reliable method for identification of large numbers of Salmonella serotypes prevalent throughout the European Union than assays using phenotypic serotyping methods.     

Detection of Salmonella spp. in water using magnetic capture hybridization combined with PCR or real-time PCR

The removal of target DNA by magnetic capture hybridization (MCH) from constituents inhibitory to amplification by polymerase chain reaction (PCR) was evaluated using Salmonella as the test pathogen. Hybrids were subjected to both conventional and quantitative real-time PCR (qPCR). When PCR inhibitors commonly found in water were added to the reaction, MCH-PCR increased the detection sensitivity on the order of 8 to 2,000-fold compared with the system using only PCR. To determine the selectivity of MCH for target DNA (Salmonella), different amounts of non-target DNA (Escherichia coli) were added to the qPCR reaction. The highest non-target DNA concentration interfered with the amplification by qPCR alone, while MCH-qPCR was unaffected. Average recovery of Salmonella DNA by MCH-qPCR was 31% using optimized buffers, washing solutions and enzymatic digestion. A recovery function was proposed in order to calculate the real cell number based on the measured value. Preliminary testing confirmed the suitability of this method for analysis of natural waters.     

A quantitative polymerase chain reaction method for the detection in avian faeces of salmonellas carrying the spvR gene.

A quick, semi-quantitative method of detecting Salmonella species which contain the virulence plasmid has been developed using the polymerase chain reaction (PCR). A pair of primers have been synthesized encompassing a 500 bp fragment of the spvR virulence gene. Competitor DNA consisting of the spvR gene with a 94 bp deletion situated between the primer recognition sequences, was cloned into a plasmid vector. Co-amplification of the ''unknown'' target salmonella DNA with known quantities of competitor DNA in the same reaction tube gave PCR products of 500 and 406 bp respectively. Visual assessment of the ratio of the two products on ethidium bromide stained agarose gels provided an estimate of the approximate number of salmonella cells present in avian faeces. The technique could be applied to detect quantifiably any non-host DNA in clinical samples if a suitable DNA sequence for primer construction is available.     

Polymerase chain reaction as a diagnostic tool

Although the method of polymerase chain reaction (PCR) is technical, the concept is simple: PCR is a sequential process that explores a sample for the presence of a known sequence of DNA or RNA. Chapter sections cover specific applications of PCR to infectious diseases with rheumatic manifestations.