福建省延平区及永安市致泻性大肠埃希菌监测分析

目的掌握福建省腹泻患者致泻性大肠埃希菌(diarrheagenic Escherichia coli,DEC)的流行特征,为防控腹泻病的流行和爆发提供依据。方法搜集2010-2015年延平区和永安市哨点医院腹泻病标本1 950份,接种于麦康凯(MaC)培养基,挑选平板上粉红色、光滑型菌落,采用常规分离培养和分子诊断技术相结合的方法分离鉴定致泻性大肠埃希菌,用SPSS 17.0对结果进行统计分析。结果致泻性大肠埃希菌共检出129株,总检出率为6.62%;EPEC检出65株,检出率为3.33%,其中aEPEC 61株,tEPEC4株;ETEC和EAEC均检出32株,检出率为1.64%;未检出EHEC和EIEC。男女DEC检出率差异无统计学意义(P0.05);将腹泻患者按照年龄分为5组,DEC检出率分别为7.03%、4.60%、3.70%、7.28%和6.21%,各组EPEC、ETEC和EAEC检出率差异无统计学意义(P0.05)。致泻性大肠埃希菌(DEC)检出率最高的月份为8月和9月;农村和城市DEC检出率差异无统计学意义(P0.05);两地区各类型DEC构成比差异无统计学意义(P0.05)。结论福建省DEC存在3种类型,以EPEC为主(其中aEPEC占绝对优势),8、9月是DEC高发月份,0~5岁婴幼儿组及成人组是DEC的高发人群,合理使用抗生素治疗DEC需要得到重视。     

山西省2015-2016年食源性疾病主动监测的病原学特征分析

目的 了解山西省食源性疾病主动监测中沙门菌、志贺菌、副溶血性弧菌、致泻性大肠埃希菌(包括粘附性大肠埃希菌EAEC、致病性大肠埃希菌EPEC、侵袭性大肠埃希菌EIEC、产毒性大肠埃希菌ETEC)的病原谱、耐药情况及分子分型。方法 对2015-2016年山西省食源性疾病主动监测病例中分离到的沙门菌、志贺菌、副溶血性弧菌、致泻性大肠埃希菌进行血清学分型、药物敏感性试验以及PFGE分型。结果 2015-2016年共采集腹泻病人标本2 505例,检出目标菌数157例,检出率为6.27%,其中致泻性大肠埃希菌82例(3.27%)、沙门菌51例(2.04%)、志贺菌14例(0.56%)、副溶血性弧菌10例(0.40%)。致泻性大肠埃希菌中,分离率最高的是EPEC。在对15种常见抗生素药敏实验中,致泻性大肠埃希菌对亚胺培南全部敏感(100%),对头孢他啶和甲氧苄啶\磺胺甲恶唑敏感率大于90%。沙门菌以肠炎沙门菌和鼠伤寒沙门菌2个血清型为主,沙门菌对亚胺培南全部敏感(100%),对头孢西丁和头孢他啶敏感率大于90%。副溶血性弧菌毒力基因全部为tdh阳性。结论 山西省2015-2016年食源性疾病主动监测中,检出率最高的是致泻性大肠埃希菌,其次为沙门菌,志贺菌,副溶血性弧菌。     

肠出血性大肠埃希菌感染的诊治

大肠埃希菌(E.coli)是人类和动物肠道内的正常菌群之一.肠出血性大肠埃希菌(enterohemorrhagic E.Coli,EHEC)是大肠埃希菌的一个亚型,分为157、26、111血清型,主要致病菌株为O157∶H7,可引起严重的腹泻、血便并出现溶血尿毒综合征(haemolytic uraemic syndrome,HUS),是近年来发现的严重危害人类健康的肠道传染病,因能引起人类的出血性肠炎而得名.     

肠道致病性大肠埃希氏菌(EPEC)和产肠毒素大肠埃希氏菌(ETEC)的噬菌体型别调查

<正> 1989年宋元堤等用何晓青分离的5株大肠埃希氏菌属分型噬菌体对从腹泻病人和动物分离的235株大肠埃希氏菌进行分型,可分为81个型。作者在1991年用该分型噬菌体对从腹泻病人和健康人分离的 160株ETEC进行分型,可分为17个噬菌体型。现将收集到的78株EPEC和270株ETEC进行分型的结果报告如下。     

炎症性肠病与肠道息肉感染致泻性大肠埃希菌实验室检测方法分析

目的 分析炎症性肠病(inflammatory bowel disease, IBD)患者和肠道息肉患者感染致泻性大肠埃希菌(diarrheagenic Escherichia coli, DEC)实验室检测方法，为该类疾病诊断提供实验室依据。方法 收集2019年1月1日至2020年12月31日我院消化内科130例IBD患者(IBD组)和79例肠道息肉患者(息肉组)的大便，常规方法培养分离大肠埃希菌，用VITEK Compact 2全自动细菌分析仪和VITEK MS全自动快速微生物质谱检测系统鉴定到种，血清学和分子生物学鉴定DEC分型。结果 大肠埃希菌分离率IBD组高于肠道息肉组(P=0.028)。肠道分离大肠埃希菌性别分布IBD组与息肉组比较，差异无统计学意义(P=0.216),年龄分布差异有统计学意义(P=0.023)。大肠埃希菌在麦康凯平板分解乳糖能力IBD组与息肉组比较，差异无统计学意义(P=0.112)。采用血清学和实时荧光PCR方法进行DEC分型鉴定，实时荧光PCR阳性14株，血清学阳性13株，血清学和实时荧光PCR分型同时阳性4株。血清学与实时荧光PCR法分型鉴定同时阴性...     

致泻大肠埃希菌在水源水中的分布与腹泻病关系的研究

目的探讨致泻大肠埃希菌在水源水中的分布与腹泻病之间的相互关系。方法腹泻病人粪便标本来自本市医院肠遭门诊，水源水为本市的主要饮用水源。标本经增菌，分离培养、纯培养、生化反应、噬菌体裂解、血清学试验等微生物学鉴定确定致泻大肠埃希菌的分布。结果定点、定时采集1080份水源水，检出致泻大肠埃希菌149株，分属23个血清型。EPEC中以O86：K61K62最为多见，O128：K67次之；EIEC中以O29：K分离菌株数最多，O28：K73次之；ETEC中以O8：K40K47最为常见，O6：K15次之；同一时期自1142份腹泻病人粪便标本中分离到致泻大肠埃希菌143株，分属23个血清型，EPEC中以O86：K61K62检出率最高，O142：K86次之，EIEC中以O29：k最为多见，O28：K73次之，ETEC中以O8：K40K7分离菌株数最多，O6：K15次之；先后自腹泻病人粪便和水源水中分离到7株产H2S致泻大肠埃希菌。结论比较同一时期自腹泻病人和水源水标本中检出的致泻大肠埃希菌，发现两者除极个别外，血清型分布几乎完全相同，两者分离的致泻大肠埃希菌EPEC、EIEC、ETEC中均是分别以O86：K61K62、O29：K08：L40K47血清型最为常见，表明腹泻病人感染致泻大肠埃希菌与水源水污染有密切关系。为制定相应的腹泻病防治对策提供了依据；产H2S致泻大肠埃希菌的发现，填补了致泻大肠埃希菌家族的一项空白。提示临床医生在腹泻病防治工作中，同时也要关注生化学变异的腹泻病原菌的检测。     

2019—2020年酒泉市致泻大肠埃希氏菌分子分型和耐药性分析

目的 了解2019—2020年甘肃省酒泉市腹泻病例粪便标本中致泻大肠埃希氏菌（DEC）的耐药情况、毒力基因型别以及时间、人群分布情况和分子分型特征,为DEC监测、暴发预警以及耐药抗生素规避使用提供依据。方法 收集2019—2020年酒泉市哨点医院送检的腹泻患者粪便标本,分离疑似致泻大肠埃希氏菌株,采用多重PCR和毛细管凝胶电泳相结合的方法进行毒力基因分型、MIC微量肉汤稀释法药敏试验及PFGE脉冲场凝胶电泳分子分型试验。结果腹泻患者粪便标本219份,检出致泻大肠埃希氏菌27株、检出率12.33%,其中肠聚集性埃希氏菌20株、占74.07%,肠致病性埃希氏菌4株、占14.81%,肠产毒性埃希氏菌3株、占11.11%;以夏季发病为主、占74.08%;人群普遍易感,以19岁～组和0岁～组人群为主,分别占44.44%和29.63%;对氨苄西林和四环素耐药分别占84.19%和74.07%,对萘啶酸、头孢唑啉和复方磺胺耐药分别占66.67%,66.67%和62.96%;27株致泻性大肠埃希氏菌分为27个型别。结论 酒泉市腹泻患者中致泻大肠埃希氏菌PFGE指纹图谱表现出多态性,感染型别以EAEC为主...     

多重PCR方法检测EHEC和EPEC毒力基因

目的 建立简易实用的检测EHEC和EPEC多种毒力基因的方法。方法 应用多重PCR同时检测大肠埃希菌菌株的stx1、stx2、EPEC和EHEC共同的eaeA(eaeA-gen）等靶基因;用常规PCR检测EHEC O157特异的eaeA(eaeA-O157）基因,以区分EHEC和EPEC的eaeA基因。结果 对分别分离自美国和我国江苏的EHEC O157菌株以MPCR检测,stx1、stx2和eaeA-gen基因均阳性,同时常规PCR扩增eaeA-O157也阳性。在8株分离自杭州的志贺毒素阴性的大肠埃希菌O157菌株中,stx1、stx2和eaeA-O157基因均阴性,仅2株扩增出EPEC eaeA基因。在28株EPEC血清型、12株ETEC血清型、12株EIEC血清型大肠埃希菌菌株中,stx1和stx2基因均阴性;3株EPEC血清型菌株eaeA-gen基因阳性。结论 MPCR技术可同时检测菌株的stx1、stx2和eaeA基因,可为EHEC和EPEC感染的诊断及流行病学调查,提供一种简便、实用、经济的技术手段。     

长春地区致儿童腹泻大肠埃希菌的分离鉴定与耐药分析

目的了解长春地区致儿童细菌性腹泻的病原菌类型、病原学特征和抗生素耐药模式,为临床合理用药提供参考。方法采集2019年长春市儿童医院和长春中医药大学附属医院儿童腹泻样品50份,进行16s rDNA扩增子高通量测序分析和大肠埃希菌的分离鉴定;E-test法测定细菌的耐药谱与抗生素最小抑菌浓度;ERIC-PCR检测细菌的同源性,并测定13种毒力基因,进行系统分群和血清型鉴定。结果通过16S rDNA扩增子组学测序分析,排除志贺菌、沙门菌等感染的可能,确定致儿童腹泻粪便样品中大肠埃希菌为优势病原菌。分离获得110株大肠埃希菌,系统进化分群以A群、B2群和D群为主。检测到O抗原血清型23种,其中优势血清型为O119,检出13株大肠埃希菌EAST1基因PCR阳性,7株eae基因PCR阳性,其中1株同时携带EAST1基因和eae基因。分离株对21种抗生素的耐药率为4.3%～68.1%,多药耐药菌菌株比例高达63.8%。49.3%的菌株为ESBL表型,喹诺酮类抗生素的耐药率约为50%,阿米卡星和碳青霉烯类抗生素耐药率较低(5.8%和4.3%)。结论长春地区致泻性大肠埃希菌是引起儿童腹泻的重要病原菌之一,存在非典型肠致病性大肠埃希菌和肠集聚性大肠埃希菌的流行。目前临床常用的β-内酰胺类和喹诺酮类抗生素已不能达到良好的治疗效果,ESBL菌株对12种抗生素有较高的耐药水平,儿童感染性腹泻大肠埃希菌的耐药形势严峻,应进一步加强耐药性监测与抗生素应用管理。     

江苏省某监测点家畜来源肠致病性大肠埃希菌分离株分子特征分析

目的 分析江苏省某监测点家畜来源肠致病性大肠埃希菌分离株分子特征,进而评估其潜在的致病性,为感染性腹泻的监测与防控提供依据。方法 采用全基因组测序技术对江苏省某监测点分离的家畜来源的37株肠致病性大肠埃希菌(EPEC)菌株进行特征性分析。结果 本地家畜来源的EPEC均为非典型EPEC(aEPEC),其血清型多样,携带多种与腹泻相关的毒力基因,有9种ST型且具有区域性流行特征,eae基因包含有5种亚型,β1为优势亚型,其在腹泻病人中也最为常见。结论 aEPEC对公众健康构成潜在威胁,应在感染性腹泻的监测工作中,加强对家畜粪便及养殖环境的监测。     

Molecular characterization of diarrheagenic Escherichia coli from Libya

Diarrheagenic Escherichia coli (DEC) are important enteric pathogens that cause a wide variety of gastrointestinal diseases, particularly in children. Escherichia coli isolates cultured from 243 diarrheal stool samples obtained from Libyan children and 50 water samples were screened by polymerase chain reaction (PCR) for genes characteristic of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorrhagic E. coli (EHEC), and enteroinvasive E. coli (EIEC). The DEC were detected in 21 (8.6%) children with diarrhea; 10 (4.1%) cases were identified as EAEC, 3 (1.2%) as EPEC, and 8 (3.3%) were ETEC; EHEC, and EIEC were not detected. All DEC were grouped phylogenetically by PCR with the majority (> 70%) identified as phylogenetic groups A and B1. The EAEC isolates were also tested for eight genes associated with virulence using PCR. Multi-virulence (≥ 3 virulence factors) was found in 50% of EAEC isolates. Isolated EAEC possessed different virulence traits and belonged to different phylogenetic groups indicating their heterogeneity.     

Diarrheagenic Escherichia coli isolated from stools of sporadic cases of diarrheal illness in Osaka City,Japan between 1997 and 2000: prevalence of enteroaggregative E. coli heat-stable enterotoxin 1 gene-possessing E. coli

Diarrheagenic Escherichia coli (DEC) represents an elusive target, since they are not easily distinguished from fecal coliforms. To clarify if DEC are prevalent among sporadic cases of diarrheal illness in Osaka City, Japan, diarrheal specimens were examined for E. coli that were enterohemorrhagic (EHEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC), or enteroaggregative (EAggEC). EAST1EC, a strain of E. coli that does not possess any diarrheagenic characteristics except the EAggEC heat-stable toxin 1 (EAST1) gene, was also included as a possible DEC. A total of 924 specimens were examined between July 1997 and March 2000. DEC and Salmonella were isolated from 7.3% (67/924) and 6.8% (63/924) of specimens, respectively. DEC was therefore as prevalent as Salmonella among sporadic cases. The 67 strains were composed of 17 EPEC (26%), 10 EHEC (15%), four ETEC (6%), 13 EAggEC (20%), and 23 EAST1EC (35%), including two strains of EAST1EC O166:H15. Although PCR and tissue culture adhesion tests were useful to detect DEC, the effectiveness of serotyping was limited: only 40 strains (17.5%) out of 229 isolates that had been assumed to be enterovirulent on the basis of their O antigen were recognized to be diarrheagenic. In conclusion, not only EHEC but also the other subgroups of DEC, including EAST1EC, seem to play an important role in causing sporadic diarrheal illnesses. Methods to detect and unified criteria to identify various kinds of DEC are strongly desired.     

Examination of diarrheal stools in Hat Yai City, South Thailand, for Escherichia coli O157 and other diarrheagenic Escherichia coli using immunomagnetic separation and PCR method

A total of 493 stool samples from diarrheal patients in Songklanagarind Hospital, in southern Thailand, were examined for Escherichia coli O157 by the culture method combined with an immunomagnetic separation (IMS) technique. E. coli O157 was not found, although the IMS-based method could detect 10(2)-10(3) CFU of artificially inoculated O157/g of stool samples. Polymerase chain reaction was also used for the detection and identification of diarrheagenic E coli from 530 stool samples. The target genes were eae for enteropathogenic E. coli (EPEC), stx for enterohemorrhagic E. coli (EHEC), elt and est for enterotoxigenic E. coli (ETEC), ipaH for enteroinvasive E. coli (EIEC), and aggR for enteroaggregative E. coli (EAggEC). Fifty-eight diarrheagenic E. coli strains were detected in 55 stool samples (10%) from 32 children and 23 adults. These included 31 EAggEC strains (5.8%), 13 ETEC strains (2.5%), 13 EPEC strains (2.5%), and one EIEC strain (0.2%). EHEC was not detected. The diarrheagenic E. coli strains were found mainly in children under 2 years of age (24 of 32 children). EAggEC strains and ETEC strains were susceptible to several antibiotics whereas the EPEC strains exhibited resistance to these antibiotics.     

Impact of vitamin A on selected gastrointestinal pathogen infections and associated diarrheal episodes among children in Mexico City, Mexico

BACKGROUND: The overall effect of vitamin A supplementation on diarrheal disease in community trials may result from its effect on specific diarrheal pathogens. METHODS: We conducted a placebo-controlled, double-blind trial of the prophylactic effect of vitamin A on gastrointestinal pathogen infections and clinical symptoms among 188 children in Mexico City, Mexico, from January 1998 to May 1999. Children 6-15 months of age were randomly assigned to receive either a vitamin A supplement (for children <12 months of age, 20,000 international units [IU] of retinol; for children > or =12 months of age, 45,000 IU of retinol) every 2 months or a placebo and were followed for up to 15 months. Stool samples, collected semimonthly, were screened for enteropathogenic Escherichia coli (EPEC), enterotoxigenic E. coli (ETEC), Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), and Giardia lamblia. RESULTS: Vitamin A supplementation reduced the prevalence of EPEC infections (rate ratio [RR], 0.52 [95% confidence interval {CI}, 0.23-0.86]) and led to shorter durations of both EPEC and ETEC infections. Supplementation also reduced the prevalence of EPEC-associated diarrhea (RR, 0.41 [95% CI, 0.16-1.00]), EPEC-associated fever (RR, 0.15 [95% CI, 0.02-0.98]), and G. lamblia-associated fever (RR, 0.27 [95% CI, 0.13-0.80]). Finally, children who received vitamin A supplementation had shorter durations of EPEC-associated diarrhea than did children who did not receive supplementation but had longer durations of G. lamblia-associated diarrhea. CONCLUSIONS: These results suggest that the effect of vitamin A supplementation on clinical outcomes may be pathogen dependent.     

Etiology of acute diarrhea in children and adults in Tunis, Tunisia, with emphasis on diarrheagenic Escherichia coli: prevalence, phenotyping, and molecular epidemiology

A total of 271 stool specimens were collected from children (diarrheagenic, n = 115 and control, n = 54) and adults (diarrheagenic, n = 73 and control, n = 29) from Tunis, Tunisia, and processed to detect bacterial enteropathogens, parasites, and viruses. Diarrheagenic Escherichia coli (DEC) were identified by their virulence genes (polymerase chain reaction) and adherence patterns (tissue culture assays). The most frequently isolated enteric pathogens from diarrheagenic children were enterotoxigenic E. coli (ETEC, 32.3%), enteroaggregative E. coli (EAEC, 11.3%), enteroinvasive E. coli (EIEC, (11.3%), adenovirus (10.4%), enterohemorrhagic E. coli (EHEC, 10.4%), and Salmonella spp. (9.5%). For children in the control group, ETEC (37%), EAEC (15%), EHEC (11.1%), and typical enteropathogenic E. coli (EPEC, 11.1%) were the most common enteric pathogens. In adults in the diarrheagenic group, Salmonella spp. (34.2%), ETEC (12.3%), adenovirus (7%), and Shigella spp. (4%) were the most common enteric pathogens. In adults in the control group, ETEC (31%) was the most common enteric pathogen. Multiple pathogens were recovered from 22% of the diarrheagenic children and 7% of the diarrheagenic adults. Escherichia coli strains showed high resistance rates to tetracycline, streptomycin, and beta-lactams. The most frequent combinations were ETEC-rotavirus and ETEC-adenovirus. Pulsed-field gel electrophoresis for DEC indicated a large number of DEC clones (five major clones) persistent in the community reservoir for a considerable period of time that caused diarrhea in the population. This suggests the confluence of small epidemics by clonally related DEC strains circulating in this region.     

High prevalence of enteroinvasive Escherichia coli isolated in a remote region of northern coastal Ecuador

Enteroinvasive Escherichia coli (EIEC) causes dysentery; however, it is less widely reported than other etiological agents in studies of diarrhea worldwide. Between August 2003 and July 2005, stool samples were collected in case-control studies in 22 rural communities in northwestern Ecuador. Infection was assessed by PCR specific for LT and STa genes of enterotoxigenic E. coli (ETEC), the bfp gene of enteropathogenic E. coli (EPEC), and the ipaH gene of both enteroinvasive E. coli and Shigellae. The pathogenic E. coli most frequently identified were EIEC (3.2 cases/100 persons) and Shigellae (1.5 cases/100 persons), followed by ETEC (1.3 cases/100 persons), and EPEC (0.9 case/100 persons). EIEC exhibited similar risk-factor relationships with other pathotypes analyzed but different age-specific infection rates. EIEC was the predominant diarrheagenic bacteria isolated in our community-based study, a unique observation compared with other regions of the world.     

Frequency and characteristics of diarrhoeagenic Escherichia coli strains isolated from children with and without diarrhoea in Rio de Janeiro, Brazil

The frequency of diarrhoeagenic Escherichia coli (DEC) strains was investigated in 253 children up to 3 years old, with (patient group, PG, 199 children) and without (control group, CG, 54 children) diarrhoea, living in Rio de Janeiro, Brazil. DEC strains were detected in 70 (27.6%) children, including 54 (27.1%) with diarrhoea and 16 (29.6%) without diarrhoea. Enteroaggregative E. coli (EAEC) was the most frequent DEC category, accounting for 14.6% of the isolates in the PG and for 11.1% in the CG. E. coli strains carrying enteropathogenic E. coli (EPEC) virulence markers showed higher incidence in the CG (12.9%) than in the PG (8.0%). E. coli strains belonging to non-classical EPEC groups that carried eae only or eae and bfpA, designated as attaching-effacing E. coli (AEEC) were the most frequent (79.1%). Simultaneous presence of multiple EPEC virulence factors (EAF/eae/bfpA) were only detected among strains isolated from the PG. Enterotoxigenic E. coli (ETEC) strains were isolated from 5.5% of the children in the CG and from 3.5% of those in the PG. Most of the ETEC isolates were LT-probe positive (70%) and none carried both LT-I and ST-I probe sequences. One enteroinvasive E. coli (EIEC) strain was recovered from a child with diarrhoea. No stx-probe positive E. coli strains were detected. Overall, DEC strains were not found to be significantly associated with diarrhoea (p>0.05). However, the higher incidence of EAEC, the most frequent DEC category, among children with diarrhoea, suggests a potential role of EAEC as an important enteric pathogen in the community investigated.     

Asymptomatic infections by diarrheagenic Escherichia coli in children from Misiones, Argentina, during the first twenty months of their lives

Diarrheagenics Escherichia coli are the major agents involved in diarrheal disease in developing countries. The aim of this study was to evaluate the time of appearance of the first asymptomatic infection by the different categories of diarrheagenic E. coli in 44 children since their birth and during the first 20 months of their lives. In all of the children studied, we detected at least one category of diarrheagenic E. coli through the 20 months of the study. 510 diarrheagenic E. coli (33.5%) were obtained from the 1,524 samples collected from the 44 children during the time of the study (31.4% EAggEC, 28.8% EPEC, 27.1% DAEC, and 12.7% ETEC). Neither EHEC nor EIEC were identified. The median age for diarrheagenic E. coli colonization was 7.5 months. The mean weaning period was 12.8 months and the mean age for introduction of mixed feeding (breast fed supplemented) was 3.8 months. A significantly lower incidence of diarrheal disease and asymptomatic infections was recorded among the exclusively breast-fed rather than in the supplemented and non breast-fed infants. For ETEC, EPEC and EAggEC the introduction of weaning foods and complete termination of breast-feeding were associated with an increase of asymptomatic infections.     

Outbreak caused by Escherichia coli in Chalco,Mexico

OBJECTIVE: To identify the etiologic agent responsible for a disease outbreak following an overflow of sewage water in Valle de Chalco, Mexico. MATERIAL AND METHODS: A retrospective cross-sectional study was carried out. Rectal samples were collected from the population of Chalco valley, who suffered from diarrhea and vomiting during a natural disaster that took place on May 31, 2000. The Instituto de Diagnóstico y Referencia Epidemiológicos (Epidemic Reference and Diagnosis Institute, InDRE, Ministry of Health), received 1521 rectal swab samples from diarrhea cases, to test for E. coli strains. Statistical analysis was performed to find a difference of proportions between cases and non-cases (chi-squared test). ETEC, EIEC, EPEC and EHEC pathogenic E. coli groups were hybridized by colony blot. RESULTS: Strains isolated were ETEC (62.2%), EIEC (0.84%), EPEC (0.84%), and EHEC non-O157:H7 (0.08%); there was no hybridization in 36.02% of E. coli strains. Other isolated microorganisms were Salmonella spp (0.45%) and Shigella spp (0.06%). CONCLUSIONS: Enterotoxigenic E. coli was the most likely etiologic agent. Sanitary control strategies should be targeted to preventing outbreaks caused by this pathogenic agent. The English version of this paper is available at: http://www.insp.mx/salud/index.html.