2015-2016年江阴市致泻性大肠埃希菌监测及其毒力基因分析

目的了解2015-2016年江阴市致泻性大肠埃希菌[肠致病性大肠埃希菌(EPEC)、肠产毒性大肠埃希菌(ETEC)、肠侵袭性大肠埃希菌(EIEC)、肠出血性大肠埃希菌(EHEC)、肠聚集性大肠埃希菌(EAEC)]的感染、分布及其毒力基因的携带情况。方法对2015-2016年哨点医院提供的感染性腹泻样本进行实时荧光定量PCR检测,确定其致病型别及其携带的毒力基因。结果 359份腹泻标本中,检出致泻性大肠埃希菌31份,检出率8.64%,其中EAEC 15份,检出率4.18%,EPEC 13份,检出率3.62%,ETEC 3份,检出率0.84%,未检出EIEC及EHEC。15株EAEC中,携带astA基因8株,携带aggR+pic基因6株,携带astA+aggR+pic基因1株。13株EPEC均携带eae基因,3株ETEC均携带estI基因。致泻性大肠埃希菌主要集中在夏秋季节高发,2015年主要以EPEC为主,2016年主要以EAEC为主。结论江阴市致泻性大肠埃希菌主要以EAEC和EPEC两个型别为主,携带的毒力基因呈多态性,显示其致病力和侵袭力具有多样性和复杂性,应加强监测。     

2014—2015年淮安市腹泻患者致泻大肠埃希氏菌病原学特征分析

目的了解淮安市腹泻患者中致泻大肠埃希菌感染情况、毒力基因、耐药性以及分子分型,为致泻大肠埃希氏菌防治提供依据。方法对2014—2015年淮安市各哨点医院和社区医院腹泻门诊患者的粪便标本运用多重PCR筛查和生化试验检测致泻大肠埃希菌,检测出菌株的进一步做药敏试验和分子分型。结果在549份腹泻标本中共检出致泻大肠埃希菌39株,检出率为7.10%。其中肠聚集性大肠埃希菌(EAEC)18株(46.15%)检出最高,其余依次为肠产毒性大肠埃希菌(ETEC)8株(20.51%)、肠致病性大肠埃希菌(EPEC)7株(17.95%)、肠出血性大肠埃希菌(EHEC)5株(12.82%)和侵袭性大肠埃希菌(EIEC)1株(2.56%)。药敏结果显示,39株致泻大肠埃希菌中1种以上耐药菌27株,占41.25%;最高耐药达到9耐,其中四环素和萘啶酸耐药率,分别为53.84%、51.28%。脉冲场凝胶电泳(PFGE)结果显示,39株致病性大肠埃希菌有不同的带型,且带型有密切的亲缘关系。EAEC单独聚类,除zx14352和zx14395外,其他带型的相似度都超过50%。结论淮安市2014—2015年致泻大肠埃希菌感染主要以EAEC为主。菌株耐药性强,多重耐药谱广。菌株的基因型呈多态性分布,有流行相关性。     

146株致泻性大肠埃希菌多重PCR结果分析

目的了解福建省致泻性大肠埃希菌分离株的流行病学特征及毒力基因携带情况,为防控感染性腹泻暴发提供客观的流行病学资料。方法 2010年6月至2016年10月通过致泻性大肠埃希菌多重PCR和单重PCR检测方法确定其致病型别,并分析其毒力基因分布。结果 2 231份粪便标本中共分离到146株致泻性大肠埃希菌,阳性率为6.54%;其中4株EPEC均为escV(+)、bfpB(+)、stx1(-)、stx2(-),65株aEPEC为escV(-)、bfpB(+)、stx1(-)、stx2(-),39株EAEC中,35株aggR(+)、3株pic(+)、1株aggR(+)、pic(+),38株ETEC中19株elt(+)、14株estIa(+)、5株elt(+)、estIa(+);男80例,女66例,3岁的57例,占39.14%,45岁的51例,占34.93%。结论福建省存在致泻性大肠埃希菌感染性腹泻病例,以婴幼儿和中老年为主要病例构成;致病型别以aEPEC为主,EAEC、ETEC次之,未检出EIEC、EHEC;相关毒力基因呈多态性携带情况,应加强其他感染性腹泻病例中5种致泻性大肠埃希菌监测。     

婴幼儿致病性大肠埃希菌的毒力基因检测研究

目的通过对婴幼儿腹泻病例粪便标本进行致病性大肠埃希菌的分离鉴定及毒力基因检测,从分子生物学方面研究致病性大肠埃希菌引起婴幼儿腹泻的分布,以降低婴幼儿致病性大肠埃希菌的感染率。方法收集江西省儿童医院2011-2012年婴幼儿腹泻病例357份粪便标本,按照致病性大肠埃希菌分离鉴定程序用EC肉汤增菌过夜,增菌后用麦康凯琼脂培养基分离培养,可疑菌用API 20E生化鉴定出大肠埃希菌,然后用聚合酶链反应(PCR)检测致病性大肠埃希菌相应的毒力基因。结果 357份腹泻患者粪便标本中,检出37份携带毒力基因的致病性大肠埃希菌,检出率为10.36%,携带毒力基因的肠聚集性大肠埃希菌(EAggEC)、肠道致病性大肠埃希菌(EPEC)、肠道侵入性大肠埃希菌(EIEC)、肠道出血性大肠埃希菌(EHEC)检出率分别为8.4%、0.56%、1.12%、0.28%,产肠毒素大肠埃希菌(ETEC)未检出。结论婴幼儿腹泻病例中致病性大肠埃希菌主要由EaggEC引起,其次为EIEC,进一步证实对致泻大肠埃希菌进行PCR毒力基因检测具有重要临床意义。     

腹泻症候群致泻性大肠埃希氏菌血清型及毒力基因检测

目的：通过对腹泻症候群中致泻大肠埃希菌的血清型和多重PCR检测,了解本地区致泻大肠埃希菌的血清群、型分布规律,所携带毒力基因及相互之间的相关性,为腹泻症候群中致泻大肠埃希菌的检测、鉴定提供科学依据,以提高阳性株的检出率。方法：对本地区2012-2013年腹泻症候群监测医院门诊未使用过抗生素腹泻患者的稀便、水样便、黏脓便或脓血便标本通过増菌、各种选择性培养基筛选出病原菌,后经生化试验、多重PCR试验和血清型分型试验进行鉴定。结果：本次检测共检出65株血清凝集致泻大肠埃希菌,分属EPEC、EIEC、ETEC,以EPEC为主,占83.08%,共8个血清型,其中血清型O55：H59、O128：H67占58.47%;共检出4种相关毒力基因,其中escV 49株（75.38%）。未分血清型菌株27株,检出相关毒力基因共5种,分属EPEC、EIEC、ETEC、EAEC,其中escV 15株（55.56%）。结论：本地区腹泻症候群中血清学阳性致泻大肠埃希菌以EPEC为主,常见血清型为O55：H59、O128：H67,毒力基因为escV、escV＋bfpB、invE、elt。未分血清型致泻大肠埃希菌毒力基因为escV、escV＋bfpB、invE、elt、astA,与已分型菌株携带基因基本一致。腹泻患者的大肠埃希菌检测中,在传统的细菌分离培养、生化试验、血清学鉴定的基础上,有必要进行大肠埃希菌的毒力基因检测,以提高阳性检出率,避免漏检,提高致泻性大肠埃希菌的诊断。     

盐城市2018年婴幼儿腹泻病原因子及其特征分析

目的了解盐城市婴幼儿腹泻的病原因子及其特征,为婴幼儿腹泻病防控提供参考依据。方法对盐城市2018年202例腹泻婴幼儿粪便标本进行肠道致病菌和诺如病毒检测,并对检出致病菌株进行脉冲场凝胶电泳(PFGE)和药敏试验。结果 202份婴幼儿腹泻粪便标本,共36份检出致病菌,其中沙门菌19株,阳性率为9.4%;致泻性大肠埃希菌16株[含astA的肠聚集性大肠埃希菌(EAEC)15株和含escV的肠致病性大肠埃希氏菌(EPEC)1株],阳性率为7.9%;肠产毒性大肠埃希氏菌(ETEC)、肠出血性大肠埃希氏菌(EHEC)和肠侵袭性大肠埃希氏菌(EIEC)未检出;福氏志贺菌1株,阳性率为0.5%;诺如病毒Π型24份,阳性率为11.9%,诺如病毒其他基因型未检出。结论盐城市婴幼儿腹泻病原因子以诺如病毒Π型、沙门菌和肠聚集性大肠埃希菌为主,肠聚集性大肠埃希菌和沙门菌对阿米卡星和庆大霉素耐药率高,对亚胺培南高度敏感。     

肠道感染致泻性大肠埃希菌的检测与流行分析

目的为检测肠道感染致泻性大肠埃希菌(DEC),并对疾病流行进行分析,为预防和诊治疾病提供依据。方法选取2009年5月-2014年5月医院消化门诊腹泻患者841例,所有患者均通过粪便标本以及PCR基因检测方法检测病原菌种类,统计致泻性大肠埃希菌,并结合患者的临床资料,分析其流行情况。结果 841例标本中检出DEC 151例,阳性率为17.95%,其中肠致病性大肠埃细菌(EPEC)22株、肠出血性大肠埃希菌(EHEC)1株、肠产毒性大肠埃希菌(ETEC)64株、肠聚集性大肠埃希菌(EAEC)15株、弥散聚集性大肠埃希菌(DAEC)29株,分别占14.57%、0.66%、42.38%、9.39%和19.21%;仅eastA基因阳性未能分类20株占13.25%;发病年龄与DEC检出率:0~12岁为6.62%、13~59岁为75.50%、≥60岁为17.88%;DEC好发于夏秋季(6~11月),共检出DEC106例占70.20%。结论 DEC是导致肠道感染腹泻的主要病原菌之一,DEC在不同季节和不同年龄的人群检出率有所差异,好发于夏秋季,且年龄在13~60岁检出率较高。     

青岛市急性腹泻患儿致泻性大肠埃希菌菌型分布和耐药性分析

目的探讨青岛市儿童致泻性大肠埃希菌的临床与病原分布特点。方法抽取2014-2015年收治的急性细菌性腹泻患儿2 000例作为研究对象,观察患儿的临床表现,并通过病原菌分析对致泻性大肠埃希菌的检出情况、造成感染的致泻性大肠埃希菌类型分布等进行分析,结合纸片扩散法对致泻性大肠埃希菌临床常用药的耐药性进行统计分析。结果对造成小儿腹泻的致病菌进行分离鉴别,共检出致泻性大肠埃希菌151株,占7.55%,排在第二位;其中尤以EPEC和ETEC所占比例最高,分别占72.19%(109/151)、16.6%(26/151),粪便伴黏液是最常见的临床表现。对不同类型致泻性大肠埃希菌的耐药情况进行分析可见,EHEC对所有抗生素均无明显耐药性,而EIEC对氧氟沙星、环丙沙星以及阿莫西林-克拉维酸钾的耐药率均为0;其他两种最为常见的菌型ETEC和EPEC也对这3种药物的耐药率最低,而对氨苄西林的耐药率最高,均在50%以上。结论致泻性大肠埃希菌是造成儿童肠道感染的主要致病菌之一,其中肠产毒性大肠埃希菌和肠致病性大肠埃希菌是最常见的两种类型,对氟喹诺酮类药物有良好的敏感性。     

杭州地区婴幼儿腹泻病原菌构成与耐药性分析

目的了解杭州地区婴幼儿感染性腹泻患者病原菌的构成及其耐药性状况。方法采集婴幼儿感染性腹泻患者新鲜粪便标本,进行增菌、分离、生化鉴定、血清分型、PCR独立基因检测和药敏试验。结果 165例样本共分离出肠道病原菌40株,阳性检出率为24.24%。其中致泻大肠埃希菌31株(18.79%);沙门菌属细菌6株(3.64%);小肠结肠炎耶尔森菌2株(1.21%);黏质沙雷菌1株(0.61%)。检出的肠道病原菌对萘啶酸、氨苄西林、四环素、强力霉素等多种抗生素明显耐药。结论杭州地区婴幼儿腹泻病原菌检出以致泻大肠埃希菌为首;致泻大肠埃希菌、沙门菌属对萘啶酸、氨苄西林、四环素类等药物普遍耐药,对氟喹诺酮类、阿莫西林/棒酸、氨基糖苷类的耐药率较低;监测腹泻病原菌构成和耐药结果,合理使用抗生素药物十分重要。     

泰州市腹泻病人中致泻大肠埃希氏菌感染状况及 病原学特征分析

摘要:目的　了解泰州市腹泻病人中致泻大肠埃希氏菌感染状况、毒力基因、分子分型以及耐药性情况,为致泻大肠埃希氏菌防治提供依据。方法　对2013年泰州市215份腹泻病人粪便标本进行多重PCR鉴定和分离培养,并对分离的致泻大肠埃希氏菌菌株进行生化鉴定、脉冲场凝胶电泳（Pulsed Field Gel Electrophoresis,PFGE）分子分型以及药敏试验。结果　215份腹泻病人粪便标本共检测出致泻大肠埃希氏菌30株,其中EPEC 20株（占9.30%）,EAEC 5株（占2.33%）,ETEC 5株（占2.33%）;PFGE结果表明,30株致泻大肠埃希氏菌PFGE带型种类多,各亲缘关系较近,但无100%的同源菌,同时PFGE分析结果表明在同一个粪便中有2种不同致泻大肠埃希氏菌感染情况存在;药敏试验表明,30株致泻大肠埃希氏菌对阿莫西林、四环素耐药性最高,3耐以及以上占63.33%。结论　泰州市腹泻病人中致泻大肠埃希氏菌感染普遍存在,并以EPEC、EAEC、ETEC感染为主,菌株的耐药性较强,耐药谱广;基因型呈多态分布,且具有流行相关性。     

Characterization of Salmonella enterica and detection of the virulence genes specific to diarrheagenic Escherichia coli from poultry carcasses in Ouagadougou, Burkina Faso

One hundred chicken carcasses purchased from three markets selling poultry in Ouagadougou, Burkina Faso, between June 2010 and October 2010 were examined for their microbiological quality. The presence of Salmonella was investigated using standard bacteriological procedures, and the isolates obtained were serotyped and tested for antimicrobial susceptibility. The presence of virulence-associated genes of the five main pathogroups of diarrheagenic Escherichia coli-Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli, and enteroinvasive E. coli-was investigated using 16-plex polymerase chain reaction (PCR) on the mixed bacterial cultures from the poultry samples. Of the 100 chicken carcasses studied, 57 were contaminated by Salmonella; 16 different serotypes were identified, the most frequent being Salmonella Derby, found in 28 samples. Four Salmonella strains were resistant to tetracycline, and two were resistant to streptomycin. Based on the PCR detection of the virulence genes, in total, 45 carcasses were contaminated by three pathogroups of E. coli: STEC, EPEC, or EAEC. The STEC and EPEC virulence genes were detected on six and 39 carcasses, respectively. EAEC virulence genes were only detected in combination with those of EPEC (on 11 carcasses) or STEC (on two carcasses). The STEC-positive carcasses contained the genes stx(1), stx(2), eaeA, escV, and ent in different combinations. None of the EPEC-positive carcasses contained the bfp gene, indicating that only atypical EPEC was present. EAEC virulence genes detected were aggR and/or pic. The high proportion of chicken carcasses contaminated by Salmonella and diarrheagenic E. coli indicates a potential food safety risk for consumers and highlights the necessity of public awareness of these pathogens.     

提高致泻性大肠埃希菌检出率的研究

目的提高食源性疾病监测中致泻性大肠埃希菌的检出率。方法采集2017年-2018年无锡市梁溪区食源性疾病监测标本272份,采用不同的方法进行可疑菌落的挑选,比较大肠埃希菌、致泻性大肠埃希菌检出率。结果 2017年、2018年分别检测食源性疾病监测标本170份、102份,筛选出大肠埃希菌100株、96株,大肠埃希菌检出率分别为58. 8%和94. 1%;采用多重实时荧光PCR分别检出致泻性大肠埃希菌15株、32株,致泻性大肠埃希菌检出率分别为8. 8%和31. 3%。2018年在ECC显色培养基上呈蓝色和无色菌落中分别检出致泻性大肠埃希菌28株和4株。结论 ECC显色培养基用于食源性疾病监测中致泻性大肠埃希菌筛选,用多重实时荧光PCR进行食源性疾病监测中致泻性大肠埃希菌确认试验,2018年大肠埃希菌、致泻性大肠埃希菌检出率较2017年有显著提高。     

Molecular characterization of enterohemorrhagic Escherichia coli hemolysin gene (EHEC-hlyA)-harboring isolates from cattle reveals a diverse origin and hybrid diarrheagenic strains

In the present study we investigated the occurrence of Escherichia coli strains harboring the gene encoding enterohemorrhagic E. coli hemolysin (EHEC-HlyA) in cattle and the association of this gene with various diarrheagenic E. coli (DEC) pathotypes. First, the bovine E. coli isolates were screened for EHEC-hlyA gene by PCR, and then they were characterized for the phylogenetic groups and the presence of the major virulence genes of different DEC pathotypes. In total, 25 virulence gene profiles were observed in 54 EHEC-hlyA+ isolates that reflect a considerable heterogeneity. The EHEC-hlyA+ strains were mostly associated with EHEC (72%), while only 7.4% were enteropathogenic E. coli (EPEC). We also showed the presence of estA gene of enterotoxigenic E. coli (ETEC) in 6 isolates (11.1%). Interestingly, two of the estA+ strains showed hybrid pathotypes with one carrying eae/estA (EPEC/ETEC), and the other one stx2/astA/estA (EHEC/ETEC). None of the isolates were related to enteroaggregative E. coli (EAggEC), enteroinvasive E. coli (EIEC), and necrotoxigenic E. coli (NTEC). The EHEC-plasmid encoded genes occurred in seven different combinations with EHEC-hlyA/saa/subA/espP being the most prevalent (46.3%). All stx −/eae+ strains carried O island 57 (OI-57) molecular marker(s) that may indicate these to be the progenitors of EHEC or strains losing stx. The most prevalent phylogroup was B1 (61.1%), but the most heterogeneous strains including the hybrid strains belonged to A phylogroup. Overall, our results indicate that cattle EHEC-hlyA encoding E. coli isolates consist of diverse diarrheagenic strains with the possible existence of hybrid pathotypes. Future studies are required to clarify the evolutionary aspects and clinical significance of these strains in humans and domestic animals.     

山东省腹泻病人携带耶尔森菌HPI毒力岛大肠杆菌的调查

目的 了解携带耶尔森菌HPI毒力岛的大肠杆菌的易感人群、感染率、临床症状、分离率。方法 对4个医院1997年6～11月就诊泻患者,进行流行病学调查并收集大便标本,进行细菌分离和鉴定。结果 在671例腹泻病人中,共检出20个属种449株致病毒,志贺菌检出率为25.48%,致泻性大肠杆菌为15.05%,对于176株疑似产志贺样毒素且具侵袭大肠杆菌(ESIEC)菌株采用irp-2、irp-B基因探针进行菌落原位杂交,检出42株携带HPI毒力岛的大肠杆菌。与42株携带HPI毒力岛的大肠杆菌相关的腹泻病人所表现的临床症状为食欲不振、腹痛、腹泻、寒战、乏力、体温正常或低热,粪例多为粘液便或水样便,日腹泻次数超过6次以上者为33例,占78.57%。各年龄组均有感染,10岁以下儿童为主,占33.33%.结论 自671例腹泻病人的粪便标本中,分离到的志贺菌占首位,致泻性大肠杆菌次之;在致泻性大肠杆菌以携带耶尔森菌HPI毒力岛的大肠杆菌为主(6.26%)。     

17株产H_2S致泻大肠埃希菌的微生物学研究

目的对水源水和腹泻病人标本中检测到的17株产H2S致泻大肠埃希菌进行一系列微生物学实验研究,为进一步了解该菌的流行病学特点以及临床诊断提供实验依据。方法自1999年10月～2005年8月,从腹泻病人标本和水源水中分离的产H2S致泻大肠埃希菌,经形态学、培养特性、生化学、血清学等微生物学鉴定,并且对菌株进一步进行了药敏试验和噬菌体裂解试验。结果在腹泻、食物中毒病人标本和水源水中分离到17株产H2S致泻大肠埃希菌,经血清学分型后,其中4株是EPEC O128：K67,ETEC O25：K19和ETEC O16：K15分别为3株,占58.8%。结论产H2S致泻大肠埃希菌与大肠埃希菌有密切的亲缘关系,是变异的致泻大肠埃希菌,在致泻大肠埃菌中占有较高的比例。致泻大肠埃希菌产H2S生化变异提示我们在注意生化反应典型的致病菌分离与鉴定时,还应注意生化变异菌株的检测和鉴定,防止该菌造成新的腹泻病的传播和蔓延。     

几种肠道菌中细胞致死性肿胀毒素的检测及其细胞毒性初步研究

目的了解肠出血性大肠杆菌、非典型致泻性大肠杆菌、志贺菌及部分肠杆菌中CDT毒素基因存在情况及其细胞毒性。方法用PCR方法检测cdt基因,并将阳性菌株培养上清与HeLa细胞共同孵育检测细胞形态的改变,初步评价CDT毒素的表达及其细胞毒性。结果在肠出血性大肠杆菌O157∶NM中,cdt基因检出率为16.28%（7/43）,其中3株为cdt-Ⅲ型,其他4株为cdt-Ⅰ型;携带HPI毒力岛的非典型致泻性大肠杆菌中cdt基因检出率为6.25%（5/80）;在志贺菌中,cdt基因检出率为2.67%（4/150）,非典型致泻性大肠杆菌和志贺菌检出的cdt基因全部为cdt-Ⅰ型。而在O157∶H7大肠杆菌、枸橼酸杆菌和沙门菌未检出cdt基因。所有cdt基因阳性菌株均使HeLa细胞出现典型的细胞肿胀变化,效应滴度介于1∶2到1∶16之间。结论CDT毒素只在肠出血性大肠杆菌O157∶NM、携带HPI毒力岛的非典型致泻性大肠杆菌和志贺菌中检出,且检出率均比国外同类菌株低,其存在是否与疾病严重程度相关及其细胞毒性机制尚须进一步研究予以证明。     

Emerging Enteropathogenic Escherichia coli Strains?

Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially diarrheagenic.     

云南战区部队首次检出携带耶尔森菌HPI毒力岛基因irp-2的大肠杆菌

目的：了解携带小肠结肠炎耶尔森菌HPI毒力岛基因irp^-2的大肠杆菌在云南战区部队腹泻患者粪便标本中的存在情况，并对其菌株做毒力试验。方法：用PCR扩增法检测毒力岛基因irp^-2，小白鼠腹腔注射检测毒力。结果：从268份腹泻病人粪便中分离的大肠杆菌菌株中，检测出携带小肠结肠炎耶尔森菌HPI毒力岛基因卸12的18株，检出率为6．72％（18／268）。毒力试验使小白鼠发病并死亡。结论：云南战区存在携带小肠结肠炎耶尔森菌HPI毒力岛基因卸12的大肠杆菌，该菌对部队指战员的健康具有潜在性的威胁。     

Virulence profiling and disease association of verocytotoxin-producing Escherichia coli O157 and non-O157 isolates in Belgium

Whereas the association of verocytotoxin-producing Escherichia coli (VTEC) O157:H7 with the hemolytic uremic syndrome (HUS) is well established, the medical importance of many non-O157 serotypes remains unclear. Using polymerase chain reaction (PCR), we have investigated the distribution of the pathogenicity island O island 122 (OI-122) and other virulence genes in VTEC belonging to seropathotypes (SPT) A through D, and assessed their association with human disease. Two hundred sixty-five VTEC isolated from human stools comprising 52 O157 (of which 14 associated with HUS) and 213 non-O157 isolates (of which 19 associated with HUS) were studied. A complete OI-122 (COI-122) was detected in all O157, but in only 35 (16.4%) of non-O157 strains. A progressive decrease in the frequency of COI-122 was observed from SPT A through D, with a concomitant increase in the frequencies of incomplete and absent OI-122. We focused on the variable virulence profiles of the non-O157 serotypes and found that COI-122 was also more frequently present in isolates associated with HUS (p=0.001). The individual genes vtx2, eae, espP, as well as the OI-122-associated genes sen, nleB, nleE, and the efa gene cluster were significantly more often present in non-O157 VTEC associated with HUS. Non-O157 isolates carrying the combined virulence profile vtx2-nleE-efa showed the strongest association with HUS (p<0.0001). Molecular risk assessment by determination of virulence profiles of individual isolates may be useful in the identification of highly virulent non-O157 strains. We showed that the detection of a specific gene combination could assist in identifying non-O157 VTEC isolates that pose a serious public health concern.