伤寒沙门菌的脉冲场凝胶电泳分型方法研究

目的：运用脉冲场凝胶电泳研究宁波市伤寒沙门菌的分子流行病学。方法：选择XbaⅠ酶对伤寒沙门菌染色体DNA进行酶切，采用脉冲场凝胶电泳技术分析电泳酶切指纹图谱，了解其流行状况。结果：14株伤寒沙门菌，根据电泳图谱分析，可分为3个带型。结论：PFGE具有分辨力高，重复性好的特点，是研究伤寒沙门菌分子流行病学较好的基因分型方法。     

Optimization of pulsed-field gel electrophoresis protocols for Salmonella Paratyphi A subtyping

Salmonella enterica serovar Paratyphi A infection has caused public health problems in some countries in recent years. Pulsed-field gel electrophoresis (PFGE) has been used for the subtyping and epidemiological investigations of some serotypes of Salmonella, mainly in outbreaks caused by non-typhoidal Salmonella. In this study, different restriction endonucleases and electrophoresis parameters were compared for the PFGE subtyping by using Salmonella Paratyphi A strain panels. Two protocols for the enzymes SpeI and XbaI showed higher discriminatory power, which may facilitate epidemiological analysis for more accurate case definition, and clonality study of Salmonella Paratyphi A.     

沙门菌脉冲场凝胶电泳分型研究

目的为研究河北省食品中污染的主要沙门菌菌株间的同源关系,特建立了脉冲场凝胶电泳(PFGE)分型方法,通过PFGE分型研究在我省建立沙门菌DNA指纹图谱基因库,以便将来对不同来源的沙门菌DNA图谱进行即时比较,确定同源性,进而确定食源性疾病的传染源、传播途径、流行范围等,为从根本上防止食源性疾病的发生提供技术基础.方法对2005～2007年间我省食源性致病菌监测网从各类食品样品中分离出的7种主要沙门菌(山夫登堡沙门菌、鸭沙门菌、阿贡纳沙门菌、猪霍乱沙门菌、德比沙门菌、伊鲁木沙门菌、肠炎沙门菌),用蛋白酶K和TE缓冲液提取菌体DNA后,用Xba I限制性内切酶消化胶块,然后在CHEF-DRⅢ型仪器上进行脉冲场凝胶电泳,电泳条件为0.5 ×TBE电泳缓冲液、冷却温度14℃、initial switch 2.16 8,final switch 63.8 8,time17hours,angle=120,6volt/cm.应用H9812作为脉冲场凝胶分子量标准.结果我省7种主要沙门菌存在的PFGE型别较多,各菌株间亲缘关系较远,在同种沙门菌间相似性系数最小值为4.4%,但也有同源菌株存在.结论7种主要沙门菌均未显示流行趋势,同时也表明PFGE是一种灵敏、可靠的研究沙门菌分子流行病学的基因分型方法.     

肠炎沙门氏菌脉冲场凝胶电泳分型研究

目的　为研究肠炎沙门氏菌菌株间的关系,特建立了分子流行病学研究方法脉冲场凝胶电泳分型方法,并对从食品中分离的肠炎沙门氏菌进行了分型研究。方法　1991～2 0 0 1年间,从河南、黑龙江等省份采集食品样品,分离出肠炎沙门氏菌,挑取单个菌落增菌,用溶菌酶、蛋白酶K和TE缓冲液依次提取菌体DNA后,用限制性内切酶XbaΙ消化胶块,然后在CHEFMapper仪上进行脉冲场凝胶电泳,电泳条件:0 . 5×TBE缓冲液、14℃、1%琼脂糖、脉冲时间5s～4 5s、2 6h、6V cm。应用λ噬菌体DNA作为脉冲场凝胶分子量标准。结果　从鸡肉、牛肉、熟肉及蔬菜中分离出30株肠炎沙门氏菌,其中18株来自河南省,绝大多数菌株(2 2株)分离于2 0 0 1年。对所得菌株进行脉冲场凝胶电泳后,结果显示30株肠炎沙门氏菌分为A、B两个型,两型图谱之间有8个条带的差异。A型菌株有19株,占全部菌株的6 3. 3% ,B型菌株有11株,占36 .7%。A型之内又可以分出2个亚型,其中A1型占78 .9% ,A2亚型与A1亚型相比的差别在于,A2型在5 0kb处有一条带缺失。在菌株分型与采集时间和采集地点之间没有相关性,但所有从鸡肉中分离到的菌株均为A1型,提示了某种有待进一步研究的流行病学趋势。结论　在研究肠炎沙门氏菌不同菌株之间的分子流行病学关系方面,脉冲场凝胶电泳是一种有     

PulseNet USA standardized pulsed-field gel electrophoresis protocol for subtyping of Vibrio parahaemolyticus

PulseNet is a national molecular subtyping network for foodborne disease surveillance composed of public health and food regulatory agencies. Participants employ molecular subtyping of foodborne pathogens using a standardized method of pulsed-field gel electrophoresis (PFGE) for conducting laboratory-based surveillance of foodborne pathogens. The PulseNet standardized PFGE protocols are developed through a comprehensive testing process. The reproducibility of the protocol undergoes an internal evaluation at the Centers for Disease Control and Prevention and an external evaluation in multiple PulseNet laboratories. Here we describe the development and evaluation of a rapid PFGE protocol for subtyping Vibrio parahaemolyticus for use in PulseNet activities. The protocol was derived from the existing standardized PulseNet protocols for Escherichia coli O157:H7 and Vibrio cholerae. An external evaluation of this protocol was undertaken in collaboration with three PulseNet USA participating public health laboratories. Comparative analysis of the PFGE fingerprints generated by each of these laboratories demonstrated that the protocol is both reliable and reproducible in the hands of multiple users.     

脉冲场凝胶电泳检测一起汤卜逊沙门菌食物中毒

目的:用脉冲场凝胶电泳对一起食物中毒所分离的汤卜逊沙门菌进行同源性分析。方法:对分离的沙门菌进行生化鉴定、血清学分型、药敏试验后,进行PFGE检测并用Bio Numerics软件对PFGE分型图谱进行分析并绘出聚类分析图。结果:此次食物中毒分离到8株沙门菌,其中5株是从病人大便或肛拭分离,1株是从厨房抹布分离,2株是从剩余食物分离。经PFGE分析,病人的5株和剩余羊肉的1株完全相同,牛肉和抹布中的2株有1～2条电泳条带的差异。结论:此次食物中毒是由羊肉携带的汤卜逊沙门菌引起。     

广州地区小川型霍乱弧菌的脉冲场凝胶电泳分析

目的分析小川型霍乱弧菌的致病相关基因型,探讨广州地区小川型霍乱流行趋势和规律。方法采用多重PCR方法检测小川型菌株的4种致病相关基因,应用脉冲场凝胶电泳技术（PFGE）对菌株进行分子分型,对PFGE图谱采用分子分型软件BioNumerics Version 4.0进行聚类分析。结果广州地区小川型菌株中存在3种致病相关基因型,即A型、B型和C型,20%感染者分离株为致病相关基因A型,80%环境分离株为致病相关基因C型。25株霍乱弧菌分为14个不同的PFGE型,归为3个聚类群（Ⅰ、Ⅱ、Ⅲ群）。每一次小川型暴发中分离的菌株PFGE克隆型相同或相近,而散发病例分离株与暴发株的PFGE型有些相同,有的差异较大。环境小川型菌株中存在PFGE克隆型的多样性,部分环境株与感染者分离株具有相近的PFGE型。结论应建立广州地区霍乱菌株的PFGE分子分型数据库,加强霍乱的预防、控制和预警。     

深圳市志贺菌脉冲场电泳分子分型分析

目的 分析深圳市2001-2006年分离志贺菌菌株之间的相关性,初步建立志贺菌的脉冲场电泳(pulsed-field gel electrophoresis,PFGE)分子分型监测网络.方法 55株志贺菌基因组DNA经Xba Ⅰ酶切,通过PFGE获得电泳图谱,利用BioNumerics软件对图谱进行聚类分析.结果 55株志贺菌被分为41种PFGE图谱,聚类分析显示32株细菌谱型属于同一个群,其余菌株谱型差异较大.结论 深圳地区存在遗传紧密相关的志贺菌流行克隆,也存在遗传不相关克隆.PFGE分子分型监测网络的建立,有助于细菌性痢疾的主动监测、暴发调查和传染源追踪.     

沙门菌脉冲场凝胶电泳分型与血清型的对应关系

目的分析沙门菌脉冲场凝胶电泳分型(PFGE)与血清分型之间的对应关系.方法选择中国细菌性传染病分子分型实验室监测网络PulseNet China沙门菌监测数据中鼠伤寒(Typhimurium)、肠炎(Enteritidis)、德尔卑(Derby)、阿贡纳(Agona)及山夫登堡(Senftenberg)前五位常见血清型菌株共1230株,进行PFGE聚类分析,以血清分型作为参照进行比对.确定这5种血清型PFGE优势带型的共有条带.结果1230株菌株中,1149株经PFGE预测的血清型与实际血清型一致,PFGE预测血清型的准确率为93.4%.5种血清型经PFGE预测的血清型阳性预测值多在90.0%以上、阴性预测值均在95.0%以上.结论PFGE聚类对5种常见血清型沙门菌血清分型具有较好的提示及验证作用.     

Pulsed-field gel electrophoresis subtyping database for foodborne Salmonella enterica serotype discrimination

Nontyphoid Salmonella is one of the main causes of bacterial gastroenteritis worldwide and is responsible for 65% of reported outbreaks of foodborne diseases in France. Serotyping is widely used for isolate preliminary identification, but it poorly discriminates strains. Rapid, efficient molecular subtyping tools have therefore been developed for the investigation of outbreaks. We evaluated the performance of the pulsed-field gel electrophoresis (PFGE) method for discrimination of 31 Salmonella serotypes frequently isolated in France. We set up a genomic database of Salmonella strains isolated from food, animals, the environment, and humans to improve the management of contamination and reactions to foodborne disease outbreaks. We studied 1128 isolates by PFGE, according to the standardized PulseNet protocol. We identified 452 PFGE patterns, 67.5% of which corresponded to a single isolate. The ability of this method to distinguish between isolates was estimated by calculating the Simpson index and the 95% confidence interval. Values obtained ranged between 0.33 (0.11-0.54) to 0.99 (0.96-1.00), depending on serotype. Epidemiological information about isolates was used for analyses of intra- and interserotype diversity results and for determining whether PFGE patterns were linked to the source of the isolate. Clustering analysis of the PFGE patterns obtained confirmed that serotype and PFGE genotype were closely linked. Some PFGE patterns were identified as major patterns, each of these patterns being found in at least 10 isolates. The database generated has already proved its effectiveness in epidemiological investigations in livestock production and foodborne outbreaks.     

Molecular analysis of Salmonella enteritidis isolates from the Caribbean by pulsed-field gel electrophoresis.

Using pulsed-field gel electrophoresis (PFGE), between 1987 and 1996 we analyzed Salmonella enteritidis isolates from gastroenteritis cases in four Caribbean countries: Barbados, Saint Kitts and Nevis, Saint Lucia, and Trinidad and Tobago. We also determined the resistance of the isolates to 12 antimicrobial agents. Of the 129 isolates of S. enteritidis available for testing, DNA digested by XbaI revealed 13 distinctive PFGE patterns. The most prevalent XbaI PFGE patterns were group 1 (88 of 129 isolates, 68.2%) and group 2 (26 of 129, 20.2%). The patterns found among S. enteritidis isolates correlated with the geographical origin of the isolates. Of the 28 isolates from Barbados, 20 of them (71.4%) belonged to XbaI PFGE group 2, and of the 93 isolates from Trinidad and Tobago, 78 of them (83.9%) belonged to group 1. SpeI digestion of S. enteritidis genome was not as discriminatory as XbaI. Overall, of the 129 isolates, 67 of them (51.9%) exhibited resistance to one or more of the 12 antimicrobial agents that we tested. The prevalence of resistance was 53.8% for the S. enteritidis isolates tested from Trinidad and Tobago, 50.0% for those from Barbados, 28.6% for those from Saint Lucia, and 100.0% for one isolate from the island of Saint Kitts. Resistance was highest to triple sulfur (59 of 129 isolates, 45.7%), followed by furadantoin (10 of 129, 7.8%), ampicillin (7 of 129, 5.4%), and carbamycin (5 of 129, 3.9%).     

Comparison of pulsed-field gel electrophoresis and ribotyping for subtyping of Vibrio cholerae O139 isolated in Thailand.

Pulsed-field gel electrophoresis (PFGE) of Cpo I-digested genomic DNA and ribotyping (Bgl I) were applied to 60 Vibrio cholerae strains including 48 V. cholerae O139 from Thailand to compare their value in differentiating strains of the present V. cholerae O139 epidemic. PFGE patterns were divided into groups A and B representing five and four subtypes, respectively, while ribotyping showed four different patterns. PFGE group B subtypes were only presented among O139 isolates from Thailand, whereas four O139 strains from Bangladesh and India showed identical PFGE group A subtypes observed in O139 isolates from Thailand. Two nontoxigenic O139 isolates from Thailand showed different and unique PFGE types as did five V. cholerae non-O139 isolates containing a gene virulence complex found in V. cholerae O139. These results indicate that PFGE (Cpo I) can resolve recent evolutionary divergence within V. cholerae O139 and offers a useful supplementary tool for following the progressing V. cholerae O139 epidemic.     

深圳市1993-2002年霍乱弧菌的脉冲场凝胶电泳分析

目的 分析深圳市1993—2002年霍乱弧菌菌株的相关性。方法 60株霍乱弧菌基因组DNA经Not Ⅰ酶切，通过脉冲场凝胶电泳获得电泳图谱，利用BioNumerics软件对图谱进行聚类分析。结果 60株霍乱弧菌被分为39种脉冲场凝胶电泳图谱，聚类分析将大部分菌株分为A、B两群。结论 深圳地区霍乱弧菌存在紧密相关的流行克隆群。霍乱弧菌的脉冲场凝胶电泳分析，有助于霍乱的主动监测和传染来源追踪。     

Development and validation of a PulseNet standardized pulsed-field gel electrophoresis protocol for subtyping of Vibrio cholerae

PulseNet is a network that utilizes standardized pulsed-field gel electrophoresis (PFGE) protocols with the purpose of conducting laboratory-based surveillance of foodborne pathogens. PulseNet standardized PFGE protocols are subject to rigorous testing during the developmental phase and careful evaluation during a validation process assessing its robustness and reproducibility in different laboratories. Here we describe the development and validation of a rapid PFGE protocol for subtyping Vibrio cholerae for use in PulseNet International activities. While the protocol was derived from the existing PulseNet protocol for Escherichia coli O157, various aspects of this protocol were optimized for use with V. cholerae, most notably a change of the primary and secondary restriction enzyme to SfiI and NotI, respectively, and the use of a two-block electrophoresis program. External validation of this protocol was undertaken through a collaboration between three PulseNet Asia Pacific laboratories (Public Health Laboratory Centre, Hong Kong, National Institute of Infectious Diseases, Japan, and International Center for Diarrhoeal Diseases Research-Bangladesh) and PulseNet USA. Comparison of PFGE patterns generated by each of the participating laboratories demonstrated that the protocol is robust and reproducible.     

Epidemiological analysis of Salmonella enterica Enteritidis isolates in Japan by phage-typing and pulsed-field gel electrophoresis.

Salmonella enterica serotype Enteritidis isolates of phage types (PTs) PT1, PT4, PT13a and PT22 derived from sporadic cases and outbreaks of food poisoning in Japan during 1994 and 1995 were analysed by pulsed-field gel electrophoresis (PFGE). While PT1 strains from 5 different outbreaks showed 14 PFGE patterns, 5 PFGE patterns were observed among PT4 isolates from 5 different outbreaks and 6 independent isolates from imported chicken. Interestingly, 8 out of 9 PT4 strains associated with foreign travel to Southeast Asia were indistinguishable in PFGE pattern from 5 independent isolates of imported chicken from England. Although both PT13a and PT22 were first reported in Japan in 1994, PT22 showed various PFGE patterns compared to PT13a which had the same pattern within an outbreak, unlike PT1. These results could indicate that multiple clonal lines of PT1 and PT22 had already spread while relatively fewer clonal lines of PT4 and PT13a might exist in Japan.     

布鲁菌脉冲场凝胶电泳图谱分型方法建立

目的 建立我国95株布鲁菌的染色体DNA脉冲场凝胶电泳图谱,进行布鲁菌的分子遗传学分类鉴定。方法 选择我国不同地区、不同时限分离的布鲁菌100株(包括19株标准布鲁菌株),应用SeaKem Gold琼脂糖胶块纯化布鲁菌完整的染色体DNA,限制性内切酶XbaI消化后,进行脉冲场凝胶电泳分离(PFGE)。结果 XbaI酶切布鲁菌基因组DNA后,可产生20~500kbp范围的15~25条酶切片段,并可以在PFGE凝胶上被很好的区分开。PFGE可在种的水平上区分布菌各种标准株,76株中国分离株可被分为39种PFGE类型,并聚为4大类。PFGE与传统分型方法比较,2者的一致性达63%。结论 脉冲场凝胶电泳图谱可对布鲁菌进行遗传学分类鉴定,在布鲁菌的分子流行病学研究中具有重要意义。     

Standardization of pulsed-field gel electrophoresis protocols for the subtyping of Escherichia coli O157:H7, Salmonella, and Shigella for PulseNet

Standardized rapid pulsed-field gel electrophoresis (PFGE) protocols for the subtyping of Escherichia coli O157:H7, Salmonella serotypes, and Shigella species are described. These protocols are used by laboratories in PulseNet, a network of state and local health departments, and other public health laboratories that perform real-time PFGE subtyping of these bacterial foodborne pathogens for surveillance and outbreak investigations. Development and standardization of these protocols consisted of a thorough optimization of reagents and reaction conditions to ensure that the protocols yielded consistent results and high-quality PFGE pattern data in all the PulseNet participating laboratories. These rapid PFGE protocols are based on the original 3-4-day standardized procedure developed at Centers for Disease Control and Prevention that was validated in 1996 and 1997 by eight independent laboratories. By using these rapid standardized PFGE protocols, PulseNet laboratories are able to subtype foodborne pathogens in approximately 24 h, allowing for the early detection of foodborne disease case clusters and often aiding in the identification of the source responsible for the infections.     

长沙市沙门菌表型特征及PFGE分子分型

目的研究长沙市沙门菌的血清型分布、耐药特点及分子流行病学特征。方法对分离自长沙地区食源性疾病粪便标本及市售食品中的70株沙门菌,用玻片凝集试验确定血清型,微量肉汤稀释法检测14种抗生素的敏感性,脉冲场凝胶电泳(PFGE)进行分子分型。结果鼠伤寒沙门菌为优势血清型,占51.43%,其次是肠炎沙门菌,占7.15%。在抗生素敏感性测试中,对氨苄青霉素、磺胺嘧啶和氯霉素的耐药率较高,分别为68.57%、61.43%和57.14%。62.86%(44/70)的沙门菌呈多重耐药,且鼠伤寒沙门菌的多重耐药率比其他血清型高,差异有统计学意义(χ2=7.068,P0.01)。PFGE分型结果显示69株沙门菌按照100%的相似度可分为57个PFGE型,36株鼠伤寒沙门菌可分为4个聚类,相似度在58.1%~100%之间。结论本市的沙门菌以鼠伤寒和肠炎沙门菌为主,PFGE分型结果显示可能存在沙门菌的流行株,且菌株耐药形势严峻。