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。     

2018-2019年江苏省食源性疾病中致泻大肠埃希氏菌流行特征及耐药性分析

目的 了解江苏省食源性疾病患者中致泻大肠埃希氏菌的病原学特征、流行状况和耐药性特征,为其预防控制和指导临床合理用药提供科学依据。 方法 从江苏省各设区市哨点医院共收集24 292例食源性疾病患者的粪便或肛拭子标本进行致泻大肠埃希氏菌检测,采用实时荧光定量PCR进行毒力基因分型,采用微量肉汤稀释法进行药敏实验。 结果 致泻大肠埃希氏菌检出率为2.48%。EAEC(36.48%)、EPEC(31.85%)及ETEC(30.00%)为主要毒力基因型。致泻大肠埃希氏菌在不同年龄（x2=33.428, P <0.001）、不同季节（x2=131.452, P <0.001）间检出率差异有统计学意义,<1岁年龄段及夏季检出率最高。致泻大肠埃希氏菌对氨苄西林耐药率最高（71.85%）;多重耐药率为64.81%。 结论 EAEC在江苏省食源性致泻性大肠埃希菌中最常见。夏季感染ETEC可能性大。多重耐药率高于往年,应加强耐药性监测。     

河南省腹泻病人5种致泻大肠埃希菌感染调查

[目的]应用多重PCR技术筛查自腹泻病人中分离的致泻大肠埃希菌,了解5种致泻大肠埃希菌的感染情况。[方法]用常规方法分离培养粪便标本中的大肠埃希菌,提取DNA,采用多重PCR扩增12对目的基因,电泳检测扩增产物,确定病原检出情况,并进行统计学分析。[结果]2007年河南省1534份标本中致泻大肠埃希菌检出率10.37%,其中EAEC(3.59%)居首位,其余依次检出EPEC(2.67%)、STEC(2.15%)、ETEC(1.63%)、EIEC(0.33%)。合并感染检出率0.78%,以ETEC合并感染居多。感染高峰在5月(19.85%),城市与农村的检出率差异无统计学意义,45～60岁组腹泻病人的检出率最高(17.00%)。[结论]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。致泻大肠埃希菌是河南省常见的腹泻病原。     

北京地区腹泻病患者致泻性大肠埃希菌感染类型及其流行特征

目的：了解北京地区腹泻人群中致泻性大肠埃希菌（DEC）毒力基因的分布及流行特征。方法对2012-2013年监测医院的腹泻患者粪便样本进行分离培养,再采用实时荧光PCR检测毒力基因。结果6370份粪便标本有253份阳性,共分离到DEC 262株,阳性检出率为4.0%（253/6370）,9份标本发现两种不同型别的DEC混合感染。肠致病性大肠埃希菌（EPEC）为42.8%,其中非典型EPEC占42.0%,典型EPEC占0.8%;肠产毒性大肠埃希菌（ETEC）为38.9%,其中耐热肠毒素基因st阳性占24.8%,不耐热型肠毒素基因lt阳性占9.9%,st和lt均阳性占4.2%;肠聚集性大肠埃希菌（EAEC）为15.3%;肠侵袭性大肠埃希菌（EIEC）为2.7%;检出1株产志贺毒素大肠埃希菌（STEC）,血清型为O26∶K60。ETEC感染具有明显的年龄分布特征;各型DEC全年均有检出,且呈季节性变化。结论北京地区腹泻病患者DEC感染类型以EPEC和ETEC为主,且EPEC分离株多为非典型,并存在混合感染,不同型别DEC感染具有年龄和季节性分布特征。     

感染性腹泻样本中致泻性大肠埃希菌的检测结果分析

致泻性大肠埃希氏菌可导致人、动物感染,引起食物中毒、尿道感染、肠道感染、脓毒症或脑膜炎症等。主要分为5类,即肠侵袭性大肠埃希菌（EIEC）、肠致病性大肠埃希菌（EPEC）、肠产肠毒素性大肠埃希菌（ETEC）、肠粘附性大肠埃希菌（EAEC）、肠出血性大肠埃希菌（EHEC）。为了解平罗县感染性腹泻样本中致泻性大肠埃希氏菌的感染情况,2011年4—12月对平罗县3家哨点医院收集到的感染性腹泻监测病例的粪便标本进行致泻性大肠埃希氏菌的检测和分析。     

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。     

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。     

社区腹泻患者感染致泻大肠埃希菌分布与耐药性分析

目的了解社区腹泻患者感染致泻大肠埃希菌(Diarrheagenic E.coli,DEC)的常见类型及耐药性,为制定有效治疗措施提供参考依据。方法收集医院2013年7-11月442例门诊腹泻患者粪便标本,采用针对肠致病性大肠埃希菌(EPEC)、非典型EPEC(ATEC)、肠产毒素性大肠埃希菌(ETEC)、肠凝聚性大肠埃希菌(EAEC)、肠侵袭性大肠埃希菌(EIEC)、产志贺毒素大肠埃希菌(STEC)6种类型DEC共11对致病基因(escV、bfpB、stx1、stx2、elt、estIa、estIb、invE、astA、aggR、pic)的特异性引物对分离得到的大肠埃希菌进行多重PCR测定;应用微量稀释法检测DEC对常用抗菌药物的敏感性。结果 442例门诊腹泻患者中130例分离到DEC,占29.4%,其中10例同时分离到两种致病菌,6例分离到同一种致病菌包括两种基因型;共分离到147株DEC,包括EAEC100株占68.0%、ETEC7株占4.8%、ATEC9株占6.1%、EIEC和STEC各1株,未分型29株占19.7%。结论社区DEC以EAEC最为常见,且出现ATEC感染;DEC对常用抗菌药物的耐药性因致病性不同而异,临床治疗需考虑DEC类型并加强耐药性监测。     

2018-2019年北京市丰台区腹泻病例感染致泻大肠埃希菌PFGE分子分型

目的了解北京市丰台区腹泻病例致泻大肠埃希菌(Diarrheagenic Escherichia coli,DEC)分布与分子分型特征,为DEC分子流行病学调查提供数据。方法对2018-2019年腹泻病例便标本多病原菌分离鉴定,采用脉冲场凝胶电泳法(Pulsed field gel electrophoresis,PFGE)对分离株进行分子分型和聚类分析。结果从954份粪便标本共分离98株DEC(10.5%,98/954),仍是腹泻病例的主要致病菌之一,其基因型以产毒性大肠埃希菌(Enterotoxigenic Escherichia coli,ETEC)为主(54.1%),其次为致病性大肠埃希(Enteropathogenic Escherichia coli,EPEC)(29.6%)和聚集性大肠埃希氏菌(Enteroaggregative Escherichia coli,EAEC)(16.3%)。菌株分子分型带型呈多态性,53株ETEC有3组菌株具有完全一致带型,可分为32种带型;26株EPEC分为23带型、16株EAEC分为14带型,带型间相似度较低。结论 DEC基因型以ETEC为主。通过PFGE分子分型提示ETEC可能存在同源菌株的持续感染,长期持续监测和分子分型,对防控和溯源具有重要意义。     

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。     

安徽省临床分离致泻性大肠埃希菌主要流行基因型及同源性分析

目的 了解安徽地区临床分离致泻性大肠埃希菌(DEC)的耐药状况、基因同源性及主要基因型.方法 采用微量肉汤稀释法进行药物敏感性试验,采用多位点序列分型(MLST)和脉冲场凝胶电泳(PFGE)分型进行基因型检测和同源性分析.结果 268株DEC中,57.1％为多重耐药菌,其中肠聚集性大肠埃希菌(EAEC)118株,肠毒素...     

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。     

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.     

Molecular Epidemiology of Diarrhoeagenic Escherichia ColiAssociated with Sporadic Cases and Outbreaks of Diarrhoea between 2000 and 2001 in India

Diarrhoeal infection caused by Escherichia coli is common in India with occasional outbreaks. However, association of different pathotypes of diarrhoeagenic E. coli (DEC) with the disease and its phenotypic and genotypic characteristics are not fully demonstrated. In this study, E. coli strains from sporadic cases and outbreaks of diarrhoea during 2000-2001 were confirmed as DEC by polymerase chain reaction (PCR) targeting the specific virulence genes. DEC represented by enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAggEC) were mostly belonged to O serogroups 25, 86a, 114 and 146. The gene astA was frequently detected among ETEC and EAggEC than EPEC. After initial screening of 200 DEC strains with serology and antibiotic susceptibility test, 32 strains representing ETEC, EPEC, and EAggEC isolated from different areas of India were included in the pulsed-field gel electrophoresis (PFGE) analysis. Using the PFGE results, the hierarchical representation of different linkage levels between the DEC strains were determined by unweighed pair-group arithmetic mean (UPGAMA) method. Except for few strains, clonotyping by PFGE revealed no correlation between pathotypes and serogroups as well as the place of isolation of the DEC strains. The prevailing clonal diversity among the different categories of DEC strains suggests that the pathotypes of DEC belonged to diverse clones.     

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。     

Susceptibility to antimicrobial agents of enteroaggregative Escherichia coli strains isolated from children with diarrhea

Enteroaggregative Escherichia coli (EAEC) are responsible for infant's persistent secretory diarrhea, traveler's diarrhea and outbreaks. Since isolated all over the world EAEC strains show a low to high level of resistance to antimicrobial agents, the aim of the study was to determine antimicrobial susceptibility and beta-lactamases extended spectrum (ESBL) production in vitro among 55 enteroaggregative E. coli strains isolated from children with diarrhea. Among the 17 antimicrobial agents tested, most of them showed good in vitro activity against EAEC isolates examined, apart from ampicylin and piperacylin (about 30% resistant EAEC strains). Three of 55 examined EAEC isolates were ESBL--producing strains. Because of the presence of ESBL--producing as well as resistant to antimicrobial agents EAEC isolates among enteroaggregative E. coli strains examined, treatment with antibiotics should be undertaken according to antibiogram.     

Enteroaggregative Escherichia coli related to uropathogenic clonal group A

Enteroaggregative Escherichia coli (EAEC) are heterogeneous, diarrheagenic E. coli. Of EAEC strains from Nigeria, 10 independent antimicrobial-resistant isolates belonged to the multilocus sequence type 69 clonal complex, to which uropathogenic E. coli clonal group A belongs. This finding suggests a recent common ancestor for these distinct groups of pathogenic E. coli.     

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。