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。     

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.     

2010-2012年河南省致泻大肠埃希菌监测

目的建立河南省致泻大肠埃希菌多重PCR分型的基线数据,分析致泻大肠埃希菌感染的流行病学特征。方法在河南省郑州、登封、周口、睢县4个地区的多家医疗机构设立监测哨点,收集可疑致泻大肠菌感染样本,采用多重PCR方法进行分型,并对致泻大肠菌分型结果和病例个人信息进行统计分析。结果 2010-2012年河南省共检测可疑致泻大肠埃希菌病例样本数1 934例,检出致泻大肠菌阳性样本为139例,检出率为7.19%。其中EPEC检出率最高为67例（3.46%）,之后依次为EAEC 56例（2.90%）、ETEC 9例（0.47%）、EHEC 7例（0.36%）、EIEC未检出。致泻大肠埃希菌感染高峰在4-5月,1-2岁组腹泻患者的检出率最高（10.81%）。结论 EAEH和EPEC是河南主要的致泻大肠菌型,应用多重PCR技术能快速鉴别粪便标本中的致泻大肠埃希菌。     

太原地区携带OI一28毒力基因组岛致泻大肠埃希菌性小儿腹泻

目的探讨携带OI-28毒力基因组岛致泻大肠埃希菌在小儿腹泻中的病原学作用。方法在山西省儿童医院采集257例腹泻病患儿粪便,做肠道病原菌常规培养和致泻大肠埃希菌血清学分型鉴定,用PCR和DNA斑点杂交检测致泻大肠埃希菌EHEC OI-28毒力基因组岛中与RTX相关的5个毒力基因。结果257例腹泻病患儿检出病原菌206株(80.16%)。其中大肠埃希菌149株(57.98%),其他肠道致病菌57株(22.18%)。血清分型检出致泻大肠埃希菌EPEC 3株(2.01%)、ETEC 2株(1.34%)、EHEC 2株(1.34%),其余142株为"疑似致泻大肠埃希菌"(55.25%)。149株大肠埃希菌中OI-28 5个基因全阳性者21株(14.09%),1个基因阳性者8株(5.37%),2个基因阳性者2株(1.34%)。21例携带OI-28毒力基因组岛大肠埃希菌感染的腹泻患儿,以3岁以下小儿为主(80.95%)。结论携带OI-28毒力基因组岛大肠埃希菌是夏季小儿腹泻的重要病原菌之一。     

Mixing of Shiga toxin-producing and enteropathogenic Escherichia coli in a wastewater treatment plant receiving city and slaughterhouse wastewater

Wastewater of human and animal may contain Shiga toxin-producing (STEC) and enteropathogenic (EPEC) Escherichia coli. We evaluated the prevalence of such strains in a wastewater treatment plant (WWTP) receiving both city and slaughterhouse wastewater. PCR screenings were performed on 12,248 E. coli isolates. The prevalence of STEC in city wastewater, slaughterhouse wastewater and treated effluent was 0.22%, 0.07% and 0.22%, respectively. The prevalence of EPEC at the same sampling sites was 0.63%, 0.90% and 0.55%. No significant difference was observed between the sampling points. Treatment had no impact on these prevalences. Enterohemorrhagic E. coli (EHEC) O157:H7 and O111:H8 were isolated from the treated effluent rejected into the river. The characteristics of STEC and EPEC differed according to their origin. City wastewater contained STEC with various stx subtypes associated with serious human disease, whereas slaughterhouse wastewater contained exclusively STEC with stx_2e subtype. All the EPEC strains were classified as atypical and were screened for the ε, γ1 and β1 subtypes, known to be associated with the EHEC mainly involved in human infections in France. In city wastewater, eae subtypes remained largely unidentified; whereas eae-β1 was the most frequent subtype in slaughterhouse wastewater. Moreover, the EPEC isolated from slaughterhouse wastewater were positive for other EHEC-associated virulence markers, including top five serotypes, the ehxA gene, putative adherence genes and OI-122 associated genes. The possibility that city wastewater could contain a pool of stx genes associated with human disease and that slaughterhouse wastewater could contain a pool of EPEC sharing similar virulence genes with EHEC, was highlighted. Mixing of such strains in WWTP could lead to the emergence of EHEC by horizontal gene transfer.     

Urban dust fecal pollution in Mexico City: antibiotic resistance and virulence factors of Escherichia coli

Fecal pollution of settled dust samples from indoor and outdoor urban environments, was measured and characterized by the presence of fecal coliforms (FC), and by the characterization of Escherichia coli virulence genes, adherence and antibiotic resistance traits as markers. There were more FC indoors than outdoors (mean values 1089 and 435MPN/g). Among indoor samples, there were more FC in houses with carpets and/or pets. Using a PCR-based assay for six enteropathogenicity genes (belonging to the EAEC, EHEC and EPEC pathotypes) on randomly selected E. coli isolates, there was no significant difference between isolates from indoors and outdoors (60% and 72% positive to at least one gene). The serotypes commonly associated with pathogenic strains, such as O86 and O28, were found in the indoor isolates; whereas O4, O66 and O9 were found amongst outdoor isolates. However, there were significantly more outdoor isolates resistant to at least one antibiotic (73% vs. 45% from indoors) among the strains positive for virulence factors, and outdoor isolates were more commonly multiresistant. There was no relationship between the presence of virulence genes and resistance traits. These results indicate that outdoor fecal bacteria were more likely from human sources, and those found indoors were related to pets and maintained in carpets. This study illustrates the risk posed by fecal bacteria from human sources, usually bearing virulence and resistance traits. Furthermore, the high prevalence of strains carrying genes associated to EAEC or EHEC pathotypes, in both indoor and outdoor environments, adds to the health risk.     

HEp-2-adherent Escherichia coli strains associated with acute infantile diarrhea,São Paulo,Brazil

In this paired case-control study of infants with diarrhea in São Paulo, we examined the association between HEp-2–adherent Escherichia coli strains and diarrhea. We tested isolates from stool specimens of infants with diarrhea and matched controls in an HEp-2 cell adherence assay; we then hybridized isolates with DNA probes and identified enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), and diffusely adherent E. coli (DAEC). From 100 patient-control pairs, we isolated 78 HEp-2–adherent strains; of these, 61 strains were single pathogens identified in stools of infants with diarrhea. While typical EPEC was significantly associated with diarrhea (p<0.001), EAEC was more frequently associated with diarrhea in clinical cases (20%) compared with healthy controls (3%) (p<0.001). Atypical EPEC, showing a localized adherence-like pattern, was also more common in patients than controls (p>0.1). DAEC was isolated with equal frequency from patients and controls (p>0.1).     

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。     

An outbreak of gastroenteritis in Osaka,Japan due to Escherichia coli serogroup O166:H15 that had a coding gene for enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1)

In an outbreak of gastroenteritis on 23 July 1996, in Osaka, Japan, 54 of 91 persons who had attended a meeting the previous day became ill. Escherichia coli O166:H15 was isolated from stool specimens of patients (29/33, 88%). Laboratory tests for other bacterial pathogens and viruses were negative. The E. coli 0166 organisms did not adhere to HEp-2 cells in a localized, diffuse, or enteroaggregative manner. The organisms did not express known enterotoxigenic E. coli (ETEC) colonization factors. In polymerase chain reaction tests, the bacteria did not have coding genes for shigatoxin of enterohemorrhagic E. coli (EHEC), heat-labile, or heat-stable enterotoxin of ETEC, attachment and effacement (eaeA) of EPEC, or invasion (invE) of enteroinvasive E. coli (EIEC). Consequently, they could not be assigned to any of the recognized diarrhoeagenic groups of E. coli: EPEC, ETEC, EHEC, EIEC, enteroaggregative E. coli (EAggEC), or diffusely adhering E. coli. However, the organisms possessed the EAggEC heat-stable enterotoxin (EAST1) gene. To our knowledge, this is the first report of an outbreak caused by E. coli that did not have well-characterized virulence genes other than EAST1. The isolates showed the same DNA banding pattern in pulsed-field gel electrophoresis after digestion with the restriction enzymes XbaI or NotI. Three O166:H15 strains isolated from two sporadic cases and another outbreak during 1997-8 were distinct, indicating that multiple clones have spread already. We propose that diarrhoeal specimens should be examined for E. coli possessing the EAST1 gene.     

致病性大肠杆菌和出血性大肠杆菌研究进展

肠致病性大肠杆菌(EPEC)是导致婴幼儿腹泻的主要病原菌,肠出血性大肠杆菌(EHEC)引起急性肾功能衰竭和溶血性尿毒综合症(HUS).近年来,国内外学者致力于EPEC和EHEC大肠杆菌的研究,并在分子生物学和细胞生物学方面取得了显著的进展.本文就EPEC和EHEC的流行病学及临床表现、重要特征、基因诊断、血清学检验、致病性及其联系进行综述.     

2013年北京市密云县食源性疾病主动监测结果分析

目的了解北京市密云县腹泻病常见食源性致病菌流行病学分布情况,提高食源性疾病发生的早期识别与溯源能力。方法分别依据国家标准GB 4789.4、GB 4789.5、GB 4789.7、GB 4789.6对哨点医院就诊的食源性疾病患者肛拭子进行沙门氏菌、志贺氏菌、副溶血性弧菌、5种致病性大肠埃希氏菌(EPEC、ETEC、EIEC、EHEC、EAEC)的检测。结果在227例食源性疾病患者肛拭子中,检出致病菌11株,检出率4.85%。其中副溶血性弧菌8株,沙门氏菌2株,致病性大肠埃希氏菌(EPEC)1株。结论密云县食源性疾病患者在8种常见致病菌中以副溶血性弧菌及沙门氏菌为主;应继续加强主动监测,降低散在的食源性疾病的发生。     

2010年福建南平及永安监测点致泻大肠杆菌的监测报告

目的:为了解福建省腹泻病人中致泻大肠杆菌的感染情况。方法:应用多重PCR或单重PCR方法检测致泻大肠杆菌的EPEC/EHEC eaeA基因、EHEC stx基因、EAEC aggR基因、EIEC ipaH、EIEC virA、ETEC ST、ETEC LT、EPEC bfp基因。API 20E生化鉴定条进行生化试验。血清学鉴定。结果:2010年度共分离得19株致泻大肠杆菌,检出率为10.9%。1株EAEC;1株tEPEC;4株aEPEC;13株ETEC。19株分离的致泻大肠杆菌经API 20E鉴定均为大肠埃希菌。1株tEPEC与EPEC三种多价诊断血清型均不凝集,而1株aEPEC血清型为O111:K58(B4)。13株ETEC菌株血清型:多数为O6:K15,1株O25:K19(L),3株未能分型。结论:监测结果对于我们了解福建省致泻大肠杆菌感染情况,预警潜在发生疫情的可能性有其重要性。这些菌种的获得可以为下一步研究其毒力特征、分子分型及耐药性积累原始材料。     

Molecular epidemiology of Escherichia coli isolated from young South African children with diarrhoeal diseases

Molecular techniques were used for studying the epidemiology of diarrhoeal infections due to Escherichia coli in the Gauteng region in South Africa. In total, 151 E. coli strains isolated from stools of patients with diarrhoea and 30 strains isolated from stools of healthy individuals were collected between March 1996 and May 1997. The E. coli isolates were characterized by serotyping, antimicrobial susceptibility testing, and adherence patterns. Polymerase chain reaction (PCR) was performed to determine the presence of the genes-encoding virulence factors. PCR showed that 59 (32.6%) of the E. coli isolates carried eaeA genes, 6 (3.3%) possessed bfpA genes, 4 (2.2%) CNF1, and 2 (1.1%) carried labile toxin and Stx2 genes. The eae genes were more prevalent in strains isolated from patients than in those from the control group (p < 0.001). Forty-eight (26.5%) strains belonged to enteropathogenic E. coli (EPEC) O serogroups and 14 (7.7%) to Shiga toxin-producing E. coli (STEC) O157 serotype. A high percentage (28.2%) of atypical EPEC strains possessing the eaeA but not the bfpA genes was isolated. Most isolates were susceptible to commonly-used antimicrobial agents. The adherence of the E. coli strains to HeLa cells was identified more in patients (69.4%) than in the control group (60%) and was more dominant in infants than in adults. PCR and tissue culture assays were shown to be useful techniques for the epidemiological study of E. coli where this organism is a major cause of diarrhoea.     

福建省非典型肠致病性大肠埃希菌的分子特征研究

摘要：目的　研究福建省非典型肠致病性大肠埃希菌（ａＥＰＥＣ）菌株的毒力基因特征和菌株间的遗传相似
度;结合菌株的背景资料分析不同的分子特征对ａＥＰＥＣ 流行的影响。方法　运用ＰＣＲ 技术进行系列的相
关毒力基因扩增;同时运用脉冲场凝胶电泳分子分型技术,对福建省２０１０－２０１２年分离的ａＥＰＥＣ 菌株进
行脉冲场凝胶电泳（ＰＦＧＥ）分子分型。结果　分离３０株实验菌株毒力基因的检测呈阳性的分别为：犫１１２１
５３．３％ （１６）,狔犻犪犃３６．７％ （１１）,狊犲狋／犲狀狋、狀犾犲犅、狀犾犲犈均为３０％ （９）,犾狆犳犃犚１４１２３．３％ （７）,犲犳犪／犾犻犳犃
２０％ （６）,犲犺狓犃３．３３％ （１）;其余毒力基因均未检出;９３．３％ （２８）菌株不同程度地携带有相关的毒力因
子。２９株菌按照１００％的相似度分为１５个ＰＦＧＥ 型别（Ｐ１ Ｐ１５）;其中存在４组不同的ＰＦＧＥ 簇（Ｉ Ⅳ）,
相同ＰＦＧＥ 簇的病例在发病的时间和地区上有聚集性,同时相同簇内菌株的毒力基因谱也表现相同。结论
　犫１１２１、狔犻犪犃和ＥＨＥＣ 毒力岛ＯＩ １２２ 相关基因（犲犳犪１／犾犻犳犃,狀犾犲犅,狀犾犲犈,狊犲狋／犲狀狋） 在福建省ａＥＰＥＣ 菌
株中携带率较高。非典型肠致病性大肠埃希菌的毒力谱表现为多样性, 基因组也呈现遗传多态性;同时
ＰＦＧＥ 分析发现福建省存在由ａＥＰＥＣ 新发病原菌引起的聚集性病例。
关键词：非典型肠致病性大肠埃希菌;毒力基因;ＰＦＧＥ
中图分类号：Ｒ３７８　　文献标识码：Ａ　　文章编号：１００９ ６６３９ （２０１４）０３ ０２１６ ０５
犕狅犾犲犮狌犾犪狉犮犺犪狉犪犮狋犲狉犻狊狋犻犮狊狅犳犪狋狔狆犻犮犪犾犲狀狋犲狉狅狆犪狋犺狅犵犲狀犻犮     

肠致病性大肠埃希菌EPEC Deng致病岛基因进化特点

目的分析肠致病性大肠埃希菌（EPEC）致病岛（PAIs）基因进化特点。方法EPEC Deng分离自我国婴幼儿腹泻患者粪便标本,鉴定该菌株血清型并进行药敏试验;采用Illumina 2000仪器对菌株进行全基因序列测序,PHAST软件定位菌株原噬菌体(prophages,PPs)在染色体中的位置,MUMmer软件进行共线性分析,构建系统发育树,了解同源基因进化规律。应用PAI_finder软件对基因组进行PAIs预测,了解PAIs核心区域（LEE）和核心基因同源进化规律,并进行遗传多态性分析。结果EPEC Deng菌株归属O119∶H6,药敏结果显示该菌株对环丙沙星、左氧氟沙星及氨苄西林耐药,对其余的抗菌药物均敏感。基因组（染色体）序列大小为5 025 482 bp（GC含量为50.52%）,质粒序列大小为207 564 bp（GC含量为49.50%）。共找到17个PPs,系统发育树分析发现,EPEC Deng株基因组与O26∶H11、O111∶H同源性较高;EPEC Deng株PAIs和核心基因均与RDEC 1和O26∶H413/89 1株具有高同源性;遗传多样性分析结果显示,紧密素（eae）及其受体（tir）多态性丰富,π值均＞0.10,Ⅲ型分泌系统（TTSS）分泌蛋白相对稳定。结论此研究明确了EPEC Deng株基因组及PAIs的进化特点,有助于了解了本土分离的EPEC基因特点。     

多重PCR快速检测食品中肠出血性大肠杆菌

本研究建立了一种快速检测食品中肠出血性大肠杆菌 (EHEC)的多重PCR方法。将样品增菌后 ,采用快速裂解吸附法制备模板 ,用多重PCR同时检测EHEC的三种毒力基因eaeA、hlyAB、slt1 2 ,相应扩增片段依次为 110 9、30 2、2 2 8bp。检测了 6 0株大肠杆菌和其它菌种。结果 12株大肠杆菌O15 7∶H7、1株大肠杆菌O2 6∶H11和 1株大肠杆菌O111∶H8同时检出上述三种基因 ,2株EAEC检出了eaeA基因 ,1株VTEC检出了slt1 2基因 ,其余 43株大肠杆菌和非大肠杆菌未检出上述基因。检测食品中EHEC时 ,从样品增菌培养到整个检测过程结束不超过 8小时 ,方法的检出限≤ 1 6cfu g(ml)。检测的 12 6份食品样品中 ,3份检出了EHEC(包括牛肉、猪肉和生菜各 1份 )。实验结果表明该法是一种特异性强、敏感性高、省时、省力的EHEC检测方法。     

顺义区重点餐饮单位凉拌菜食品监测分析

目的:掌握北京市顺义区餐饮单位凉拌菜食品中食源性致病菌的污染现况和动态变化趋势,为卫生行政部门提供监督执法依据。方法:从2007年6月~2008年6月对顺义区20家重点餐饮单位凉拌菜食品进行抽检,共抽检样品453件,检测项目为大肠菌群、沙门氏菌、志贺氏菌、金黄色葡萄球菌、致病性大肠埃希氏菌(EPEC)、出血性大肠埃希氏菌(EHEC O157H7)、变形杆菌、单增李斯特菌、蜡样芽孢杆菌计数。结果:样品总体合格率为73.1%,夏秋季节凉菜样品更容易受到细菌的污染(x2=38.26,P=0.0001),其中9件样品检出致病菌,致病菌总体阳性率为1.98%,7件样品检出金黄色葡萄球菌,检出率为1.55%,2件样品检出单增李斯特菌,检出率为0.44%,其余几种食源性致病菌均未检出。结论:顺义区凉拌菜食品存在一定卫生安全隐患,建议卫生行政部门加强监督执法力度及食品卫生从业人员卫生知识培训等一系列措施,降低食源性疾患的发生风险。     

Enteropathogenic and enterotoxigenic Escherichia coli as aetiological factors of infantile diarrhoea in rural and urban Ghana

There are 4 recognized classes of Escherichia coli that cause diarrhoeal disease in humans: enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC), and enterohaemorrhagic E. coli (EHEC). Preliminary analysis of enterotoxin production in a rural community in Ghana showed a prevalence of 11.0% LT-ST+, 9.5% LT+ST- and 7.5% EPEC. (LT = heat-labile, and ST = heat-stable, enterotoxin). The results of a similar study in an urban community in Accra, Ghana, showed 10.9% LT-ST+, 5.9% LT+ST-, 1.6% LT+ST+ and 6.5% EPEC. 14 different serotypes of EPEC were isolated in the urban area, whereas 6 serotypes and two untypable strains were isolated in the rural area. The most common serotype isolated in Accra was 0126:K71 and that from the rural area was 0128:K67. Serotypes 0143:KXI and 0155:K59 are reported for the first time in Ghana.     

不同来源肠致病性大肠杆菌(EPEC)分离株eae基因分析

目的了解我国不同来源肠致病性大肠杆菌分离株携带的eae基因型别。方法 PCR扩增eae基因,扩增产物测序后在NCBI中进行BLASTn搜索比对,确定其基因型别,并用最大似然法构建eae基因进化树,分析eae基因各型别间的相互关系。结果 130株EPEC菌株中,100株获得了1.8 kb序列,共分为18种eae基因型别,其中以β1型为主,占37%(含37株菌)。人源和动物源EPEC菌株存在相同的eae型别。结论我国EPEC分离株的eae型别呈多样性。     

4株EPEC(O111:K58)的分离鉴定及血清学试验

[目的]探讨引起食物中毒的致病性大肠埃希菌（EPEC）Olll：K58的分离鉴定及血清学试验。[方法]依据GB／T4789．6—2003对4份食物中毒患者肛拭或粪便进行培养分离，经染色镜检，生化反应，血清学试验作出鉴定，并对该起食物中毒进行流行病学调查。[结果]从食物中毒患者的3份肛拭和1份粪便均检出并确证为致病性大肠杆菌EPEC（Olll：K58）；并确定导致食物中毒的病因是由致病性大肠肝菌EPEC（Olll：K58）引起。[结论]致病性大肠埃希菌引起的食物中毒可达到快速检验和鉴定。