合肥地区动物源性大肠埃希菌的血清型分布与耐药性分析

目的了解安徽省合肥地区动物源性大肠埃希菌的血清型分布和耐药状况,以期筛选出菌苗株和指导临床合理用药。方法对46份疑似大肠埃希菌病病料进行细菌分离培养、生化编码鉴定和致病性测定。采用玻片凝集试验对分离到的46株致病性大肠埃希菌进行血清型鉴定。同时分别采用K-B纸片琼脂扩散法和双纸片增效法检测致病性大肠埃希菌的耐药性和ESBLs阳性菌株。结果46株致病性大肠埃希菌中,除7株细菌未能定型外,其余39株细菌分布于10个血清型,O127：K63血清型为优势血清型,占定型菌株的33．33％。46株致病性大肠埃希菌对21种抗菌药物均呈现不同程度的耐药性,15个ESBLs阳性菌株表现为多重耐药,对各种抗菌药物的耐药率均高于ESBLs阴性菌株。结论O127：K63血清型为优势血清型,可作为菌苗株。合肥地区动物源性大肠埃希菌耐药性较为严重,尤其是产ESBLs大肠埃希菌多重耐药更为突出。     

临沂市肉鸡致病性大肠埃希菌的分离鉴定及耐药性研究

目的查清临沂市肉鸡大肠埃希菌的优势血清型及耐药情况,为研制疫苗和科学防治本病提供依据。方法对病料进行细菌分离培养,应用形态学检查、生化试验、致病性试验和血清学试验对大肠埃希菌及其血清型进行鉴定,通过药敏试验研究其耐药性。结果从365份病料中,分离出大肠埃希菌311株,分离率为85.2%。优势血清型为O78、O1、O11、O18、O15和O2;对链霉素、氨苄西林、利福平、庆大霉素、恩诺沙星、环丙沙星和左氧氟沙星等药物表现出很高的耐药性,耐药率分别为98.0%、87.3%、86.0%、77.3%、73.4%、70.0%和64.6%,而对大观霉素、头孢噻呋、多黏菌素、氟苯尼考和痢菌净高敏。结论临沂市肉鸡大肠埃希菌的优势血清型有O78、O1、O11、O18、O15和O2,分离菌株对大部分抗菌药物产生耐药性。因此,治疗鸡大肠埃希菌病应通过药敏试验,合理地选择药物。     

山东省某地区奶牛源大肠埃希菌的血清型、耐药特性及分子特性

【目的】旨在对从山东省某地区4个健康奶牛养殖场分离到的大肠埃希菌进行优势血清型、耐药特性、Ⅰ类整合子基因盒携带情况以及系统进化群分析。【方法】采集194份来自山东省某地区4个规模化奶牛场奶牛新鲜粪便样品,进行大肠埃希菌分离和鉴定,利用常用大肠埃希菌诊断血清进行血清型鉴定;利用10%的绵羊血平板检测溶血性;利用K-B法检测对14种常规抗菌药物的敏感性;利用聚合酶链式反应(PCR)检测革兰阴性菌常见的6大类24种耐药基因、Ⅰ类整合子基因盒结构并对目的条带测序分析;利用细菌多位点序列分型(Multilocus sequence typing,MLST)技术分析大肠埃希菌的ST型并使用eBURST v3软件分析菌株之间的克隆关系。【结果】从194份新鲜粪便样品中分离到171株大肠埃希菌,其中主要为致病性(19.9%)和侵袭性大肠埃希菌(17.0%),优势血清型分别为O128:K67(12/171)和O143:K7(12/171)。另外,具有溶血性的大肠埃希菌阳性率为9.4%(16/171);药敏试验结果显示多重耐药菌株的比率为22.2%,其中对氨苄西林耐药率最高为33.9%,四环素次之,为24.0%;PCR检测耐药基因和整合子结果显示,59.1%的菌株携带β-内酰胺类耐药基因blaTEM,59.1%的菌株携带氨基糖苷类耐药基因ant(2′),未检测到四环素耐药基因tetA和tetB;Ⅰ类整合子的阳性率为4.1%(7/171),dfrA12-aadA2-sul1为优势基因盒结构(4/171);MLST将大肠埃希菌分为8种ST型,其中,ST155(10/171)和ST58(45/171)形成一个克隆复合物且没有发现新的ST型。【结论】本研究证实,从该地区规模化健康奶牛场新鲜粪便中分离到的大肠埃希菌优势血清型为O128:K67和O143:K7;少部分大肠埃希菌具有溶血性;仅对氨苄西林、四环素等具有较高的耐药率;优势基因盒结构为dfrA12-aadA2-sul1;MLST分型显示不同奶牛场分离出亲缘关系较近的菌株,其分布具有多态性,血清型与ST型之间无相关性。本研究表明源自表观健康的奶牛的大肠埃希菌存在多重耐药现象,具有食品公共卫生安全隐患,该研究对于提升规模化奶牛场奶制品的安全生产与质量评估具有一定的理论指导意义。     

新生儿大肠埃希菌败血症耐药性分析

目的 探讨新生儿败血症的大肠埃希菌耐药情况,为早期诊断和合理治疗提供依据.方法 对2002年8月至2011年8月确诊的64例大肠埃希菌败血症新生儿的药敏结果进行回顾性分析,并对早、晚发型新生儿败血症的大肠埃希菌分离株耐药率进行比较.结果 64株大肠埃希菌分离株中,产ESBLs 29株,检出率为45.31％.其中晚发型败血症ESBLs检出率明显高于早发型(56.41％ vs 28.00％,P＜0.05).早、晚发型新生儿败血症的大肠埃希菌分离株均对亚胺培南、美罗培南、哌拉西林/他唑巴坦、头孢哌酮/舒巴坦耐药率较低,均小于26.00％;早、晚发型新生儿败血症的大肠埃希菌分离株对多种抗生素的耐药率不同,差异具有统计学意义(均P＜0.05).结论 新生儿早发型与晚发型败血症的大肠埃希菌分离株对药物的耐药率有差异,建议临床在抗感染治疗时,应根据药敏结果,合理使用抗菌药物.     

高校学生宿舍室内空气中产超广谱β-内酰胺酶大肠埃希菌分离株ERIC-PCR指纹图谱分析

【目的】了解大学生宿舍空气中产超广谱β-内酰胺酶(ESBLs)大肠埃希菌的检出率和分离株之间的遗传相似性, 为预防和控制传染病的传播提供依据。【方法】用FA-1型六级筛孔撞击式空气微生物采样器采集大学生宿舍内室内空气并分离鉴定其中的产ESBLs大肠埃希菌, 采用ERIC-PCR扩增基因组DNA, 形成聚类图谱, 分析分离株的相似性。【结果】从收集到的300份空气样品中分离鉴定出194株大肠埃希菌, 30株鉴定为超广谱β-内酰胺酶分离株, 检出率达15.46%; 产ESBLs大肠埃希菌ERIC-PCR指纹图谱条带相似性在50%?100%之间。【结论】大学生宿舍空气中存在着产ESBLs大肠埃希菌污染, 应加强对空气中大肠埃希菌耐药性监测。     

巴马小型猪大肠埃希菌的分离鉴定及耐药性试验

目的分离鉴定引起巴马小型猪腹泻的细菌并筛选出对其敏感的特效药物。方法通过常规细菌学检测、分子生物学鉴定、生化试验等方法对疑似细菌感染的巴马小型猪进行分析,同时选用呋喃妥因、美满霉素、庆大霉素等25种药物对分离的细菌进行药敏实验。结果通过以上实验判定巴马小型猪为大肠埃希菌感染引起的腹泻,血清型为O138;药敏试验分析结果表明,该菌株仅对青霉素、链霉素、头孢曲松和呋喃妥因4种药物敏感,对磷霉素、磺胺脒、左氟沙星等高度耐药。结论大肠埃希菌广泛存在耐药性,该研究结果为防治相关实验动物大肠埃希菌感染提供理论依据。     

2007年上海市儿童社区获得性腹泻致病菌谱分析

为了解上海地区社区获得性腹泻儿童致病菌流行病学情况,对2007年度就诊于我院的2871例社区获得性腹泻患儿进行粪便弯曲菌、志贺菌、沙门菌,霍乱弧菌、副溶血性弧菌、致腹泻大肠埃希菌、气单胞菌、耶尔森菌进行培养分离、鉴定及部分菌株的血清分型。结果发现,弯曲菌在腹泻患儿粪便中的分离率为11.1%(172/1556),4月份感染率最高(P<0.001),多见于1～4岁儿童(P<0.05);其次是志贺菌,分离率为3.2%(91/2871),其中福氏志贺菌占63.7%;第3位是致腹泻大肠埃希菌,分离率为1.0%(30/2871),其中肠致病性大肠埃希菌占70.0%,以O55/K59血清型为主。沙门菌、气单胞菌分离率不超过0.5%,未检测到霍乱弧菌、副溶血性弧菌和耶尔森菌。本次调查显示,弯曲菌、志贺菌、致腹泻大肠埃希菌是目前上海地区儿童社区获得性腹泻的3种主要致病菌。弯曲菌感染率明显高于志贺菌及致腹泻大肠埃希菌,提示临床微生物室应将弯曲菌、致腹泻大肠埃希菌作为儿童社区获得性腹泻常规监测的病原微生物。     

重庆地区儿童感染患者11039株大肠埃希菌的临床分布及耐药性

目的分析2010-2015年重庆地区儿童感染的11 039株大肠埃希菌的临床分布特征及耐药性,为合理应用抗菌药物和预防控制医院感染提供依据。方法分析大肠埃希菌对19种抗菌药物的耐药性,采用BD Phoenix 100 MIC法结合K-B纸片扩散法进行药敏试验,按美国临床实验室标准化委员会(CLSI)标准判断结果。结果大肠埃希菌总检出率为13.53%;大肠埃希菌在呼吸病房和新生儿病房的检出率高于其他病房;以痰标本多见,占62.22%(6869/11039);大肠埃希菌对氨苄青霉素耐药率最高(90.33%),对美罗培南、亚胺培南的耐药率低,分别为0.81%和0.78%。ESBLs平均检出率为50.98%(5628/11039)。结论大肠埃希菌的耐药性呈上升趋势,呼吸病房和新生儿病房是预防控制的重点科室。     

大肠埃希菌的分型研究

目的分析上海某医院各科室分离大肠埃希菌的药敏状况和致病性,了解大肠埃希菌在该院流行情况。方法采用K-B琼脂法进行药敏试验,多重PCR技术进行基因分型。结果药敏结果显示该菌对多种常用抗生素具有耐药性,仅对阿米卡星等药物敏感。85株菌分为4个基因型,其中B2型25株,致病性最强;D型37株,致病性次之。菌株间亲缘关系表明可能存在院内流行。结论实验获得菌株具有较强耐药性和致病性,应当采取相应的措施预防院内感染的流行。     

大肠埃希菌和肺炎克雷伯菌超广谱β-内酰胺酶产生情况及变迁

目的：了解本院培养病原菌超广谱β-内酰胺酶的产生情况及变迁。方法：采用双纸片扩散法对临床分离的194株大肠埃希菌和115株肺炎克雷伯菌进行ESBLs检测。结果：ESBLs总检出率为32.4%,其中大肠埃希菌为34%,肺炎克雷伯菌为30%,1998～2000年,不同年度两菌ESBLs总检出率分别为30.2%、25.4%、38.5%,大肠埃希菌分别为28%、26%、43%。肺炎克雷伯菌分别为33%、24%、29%。经卡方检验,不同年度ESBLs检出率差异无显著性。结论：本院培养的大肠埃希菌和肺炎克雷伯菌ESBLs检出率高,对临床分离的肠杆菌属细菌进行ESBLs检测是非常必要的。     

Relationship between O-serogroup and presence of pathogenic factor genes in Escherichia coli

A total of 383 isolates of serogroup-based enteropathogenic and enteroinvasive Escherichia coli (310 strains of EPEC and 73 strains of EIEC) were examined for the presence of corresponding pathogenic genes. The serogroup-based EPEC consisted of 232 strains isolated from diarrhea patients and of 78 strains from healthy carriers. The gene encoding intimin, eaeA, was detected in 42 of the 232 EPEC strains from patients (18.1%) and 9 of the 78 strains from carriers (11.5%). The difference was not significant. The bfp gene on the EAF plasmid was detected in 7 of the 42 eaeA-positive EPEC strains from patients but was not detected in the 9 strains from carriers. In serogroup-based EIEC, a chromosomal ipaH gene encoding one of the invasive plasmid antigens was detected in 4 of the 60 strains from patients (6%) but not in the 13 strains from carriers. The 4 ipaH-positive strains possessed the invasive plasmid. These results suggested that the serogroup-based diagnosis of EPEC and EIEC is not sufficient for identifying strains carrying the eaeA or ipaH gene.     

Verotoxin-producing Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) isolated from healthy cattle in Spain

AIMS: To determine the prevalence and characteristics of verotoxigenic Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) in healthy cattle. METHODS AND RESULTS: Faecal samples from 412 healthy cattle were screened for the presence of VTEC, EPEC and NTEC. Four isolates from each sample were studied. VTEC, EPEC and NTEC were isolated in 8.7%, 8.2% and 9.9% of the animals, respectively. VTEC and NTEC were isolated more frequently from calves and heifers than from adults. Seventy (4.2%), 69 (4.2%) and 74 (4.5%) of the 1648 E. coli isolates were VTEC, EPEC and NTEC, respectively. Seventeen (24.3%) of the VTEC strains were eae-positive. Thirty-six (51.4%) of VTEC strains belonged to E. coli serogroups associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. The serogroups most prevalent among the EPEC strains were O10, O26, O71, O145 and O156. CONCLUSIONS: Healthy cattle are a reservoir of VTEC, EPEC and NTEC. SIGNIFICANCE AND IMPACT OF THE STUDY: Although most of the VTEC strains were eae-negative, a high percentage of VTEC strains belonged to serogroups associated with severe disease in humans.     

Characterization of tccP2 carried by atypical enteropathogenic Escherichia coli

Atypical enteropathogenic Escherichia coli (EPEC) comprise an important group of paediatric pathogens. Atypical EPEC have reservoirs in farm and domestic animals where they can be either commensal or pathogenic; serogroup O26 is dominant in humans and animals. Central to intestinal colonization by EPEC is the translocation of the type III secretion system effector Tir into enterocytes, which following phosphorylation (Tir-Yp) recruits Nck to activate the N-WASP actin signalling cascade. The authors have recently shown that typical EPEC strains, belonging to the EPEC-2 lineage, carry a tir gene encoding Tir-Yp and can also use the alternative TccP2 actin-signalling cascade. The aim of this study was to determine if tccP2 is found in atypical EPEC isolated from human and farm animals. tccP2 was found at a frequency of 41% in non-O26 EPEC isolates and in 82.3% of the O26 strains. TccP2 of human and animal strains show high level of sequence identity. It is shown that most strains carry a tir gene encoding Tir-Yp. In addition the authors identified two new variants of tir genes in EPEC O104:H12 and NT:H19 strains.     

Isolation and characterization of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) from calves and lambs with diarrhoea in India

AIMS: To determine the prevalence and molecular characteristics of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) in calves and lambs with diarrhoea in India. METHODS AND RESULTS: Faecal samples originating from 391 calves and 101 lambs which had diarrhoea were screened for presence of E. coli. A total number of 309 (249 bovine and 60 ovine) E. coli strains were isolated. A total of 113 bovine and 15 ovine strains were subjected to multiplex polymerase chain reaction (m-PCR) for detection of stx1, stx2, eaeA and EHEC hlyA genes. STEC and EPEC belonging to different serogpoups were detected in 9.73% of calves studied. Six per cent and 26.66% of lambs studied were carrying STEC and EPEC, respectively. Majority of the STEC serogroups isolated in this study did not belong to those which have been identified earlier to be associated mainly with diarrhoea and enteritis in cattle and sheep outside India. The most frequent serogroup among bovine and ovine EPEC was O26 (40%). One of the most important STEC serogroup O157, known for certain life-threatening infections in humans, was isolated from both bovine and ovine faecal samples. CONCLUSIONS: A high percentage of STEC and EPEC belonging to different serogroups are prevalent in calves and lambs with diarrhoea in India and could be the cause of disease in them. SIGNIFICANCE AND IMPACT OF THE STUDY: The study reports, for the first time, the isolation and characterization of STEC and EPEC serogroups associated with diarrhoea in calves and lambs in India. Many STEC and EPEC strains belonged to serogoups known for certain life-threatening diseases in humans.     

Distribution of class 1 integrons among enteropathogenic Escherichia coli

The aim of this study was to investigate the incidence of and resistance gene content of class 1 integrons among enteropathogenic Escherichia coli (EPEC) and non-EPEC and to investigate intraspecies genetic diversity of EPEC strains isolated from children with diarrhea in Iran. Twenty-eight EPEC and 16 non-EPEC strains isolated from children with diarrhea were tested for the presence of a class 1 integron associated integrase gene (int1). Sequence analysis was performed to identify the resistance gene content of integrons. Genetic diversity and cluster analysis of EPEC isolates were also investigated using enterobacterial repetitive intergenic concensus-polymerase chain reaction (ERIC-PCR) fingerprinting. Twenty-three (82%) EPEC isolates and 11 (68.7%) non-EPEC isolates harbored the int1 gene specific to the conserved integrase region of class 1 integrons. Sequence analysis revealed the dominance of dfrA and aadA gene cassettes among the isolates of both groups. ERIC-PCR fingerprinting of EPEC isolates revealed a high diversity among these isolates. The widespread distribution of 2 resistance gene families (dfrA and aadA) among both groups of EPEC and non-EPEC isolates indicates the significance of integrons in antibiotic resistance transfer among these bacteria. Furthermore, clonal diversity of EPEC isolates harbouring a class 1 integron also suggests the circulation of these mobile elements among a diverse population of EPEC in this country.     

Serovars of multi-antibiotic resistant Escherichia coli from the freshwater environs of Calcutta, India

For a period of one year (March 1987 to February 1988), the incidence of Escherichia coli was determined in water, sediment and plankton collected from two sampling sites in a freshwater lake extensively used by humans and animals. Densities of E. coli associated with plankton was the lowest while sediments, especially at site 2, harbored high densities of the organism. Correlation coefficients revealed that the density of E. coli in water samples was linearly correlated to temperature, pH of water, sediment and humidity. Stepwise multiple regression analysis, however, showed that sediment temperature was the dominant variable which could explain 27% of the observed variation in the numbers of E. coli in the overlying waters (p = less than 0.001). Of the 150 environmental E. coli strains which were characterized, 31 (20.7%) were found to belong to the classic enteropathogenic E. coli (EPEC) serogroups. Seven of the serogroups among the environmental EPEC strains were also encountered from EPEC strains isolated from human cases during a concurrent clinical study. None of the 150 environmental strains were enterotoxigenic or enteroinvasive but 4 strains possessed HEp-2 cell adhesive factor. With the exception of one, all the EPEC strains isolated were multi-drug resistant. From this study, it was evident that the lake is an important source of infection of EPEC and other related diarrheagenic E. coli.     

Development of an enzyme-labeled oligonucleotide probe for detecting the Escherichia coli attaching and effacing A gene.

Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic Escherichia coli (EHEC) can produce attaching and effacing (AE) lesions on intestinal epithelium in vitro and in vivo. A gene necessary to cause the AE lesion has been identified and designated Escherichia coli attaching and effacing A (eaeA) gene. In this study, an alkaline phosphatase (ALP)-conjugated oligonucleotide probe for the eaeA gene was developed and used to detect the eaeA gene among 163 strains of classical EPEC and 25 strains of EHEC O157. The prevalence rates of eaeA gene in the strains of classical EPEC and EHEC O157 were 51.5 and 100%, respectively. The eaeA-positive rate (60.0%) in strains of class I EPEC serogroups (O26, O55, O86, O111, O119, O125, O126, O127, O128ab, and O142) was significantly higher than that (22.9%) in strains of the class II EPEC serogroups (O18, O44, O114) (P<0.01). A total of 109 eaeA-positive classical EPEC and EHEC O157 were positive for fluorescent actin staining (FAS) assay, whereas 79 eaeA-negative classical EPEC were negative. Both the sensitivity and specificity of the eaeA probe versus the FAS assay positivity were 100%. Thus, use of the ALP-conjugated oligonucleotide probe for the eaeA gene would be specific and reliable in identifying the adherence capability of EPEC and EHEC.     

Vero cytotoxin production and HeLa cell adherence of enteropathogenic Escherichia coli of infantile diarrhoea in Iran

A total of 70 enteropathogenic Escherichia coli (EPEC) strains belonging to 11 serogroups, isolated from infantile diarrhoea in Tehran, Iran, were tested for the production of verocytotoxin (VT), enterotoxin, and also for their adherence to HeLa cells. In total 55 (78.5%) strains were either VT (32 strains) or enterotoxin (23 strains) producers, and of these 8 strains produced both VT and enterotoxins. 57 (81.4%) strains showed either Localized (LA) or Diffuse adherence (DA) or both types of adhesion (LA/DA) on HeLa cells, with strains showing LA/DA in the same preparations being dominant (32 strains), followed by those showing LA (14 strains) and DA (11 strains). Among adherent EPEC, 26 (37.1%) strains belonging to the serogroups 020, 086, 0119, 0125, 0126, 0127 and 0128 also produced VT. These findings suggest that production of VT and enterotoxin is an important factor in the pathogenesis of EPEC diarrhoea in Iran and that the combination of adherence and production of toxins is a common feature of EPEC strains which cause diarrhoea in this country.     

Identification of two new intimin types in atypical enteropathogenic Escherichia coli.

Stool specimens of patients with diarrhea or other gastrointestinal alterations who were admitted to Xeral-Calde Hospital (Lugo, Spain) were analyzed for the prevalence of typical and atypical enteropathogenic Escherichia coli (EPEC). Atypical EPEC strains (eae+ bfp-) were detected in 105 (5.2%) of 2015 patients, whereas typical EPEC strains (eae+ bfp+) were identified in only five (0.2%) patients. Atypical EPEC strains were (after Salmonella) the second most frequently recovered enteropathogenic bacteria. In this study, 110 EPEC strains were characterized. The strains belonged to 43 O serogroups and 69 O:H serotypes, including 44 new serotypes not previously reported among human EPEC. However, 29% were of one of three serogroups (O26, O51, and O145) and 33% belonged to eight serotypes (O10:H-, O26:H11, O26:H-, O51:H49, O123:H19, O128:H2, O145:H28, and O145:H-). Only 14 (13%) could be assigned to classical EPEC serotypes. Fifteen intimin types, namely, alpha1 (6 strains), alpha2 (4 strains), beta1 (34 strains), xiR/b2 (6 strains), gamma1 (13 strains), gamma2/q (16 strains), delta/k (5 strains), epsilon1 (9 strains), nuR/e2 (5 strains), zeta (6 strains), iota1 (1 strain), muR/iota2 (1 strain), nuB (1 strain), xiB (1 strain), and o (2 strains), were detected among the 110 EPEC strains, but none of the strains was positive for intimin types mu1, mu2, lambda, or muB. In addition, in atypical EPEC strains of serotypes O10:H-, O84:H-, and O129:H-, two new intimin genes (eae-nuB and eae-o) were identified. These genes showed less than 95% nucleotide sequence identity with existing intimin types. Phylogenetic analysis revealed six groups of closely related intimin genes: (i) alpha1, alpha2, zeta, nuB, and o; (ii) iota1 and muR/iota2; (iii) beta1, xiR/beta2B, delta/beta2O, and kappa; (iv) epsilon1, xiB, eta1,eta2, and nuR/epsilon2; (v) gamma1, muB, gamma2, and theta; and (vi) lambda. These results indicate that atypical EPEC strains belonging to large number of serotypes and with different intimin types might be frequently isolated from human clinical stool samples in Spain.     

Prevalence of diarrheagenic Escherichia coli in children with diarrhea in Salvador, Bahia, Brazil

We report the frequency of the different diarrheagenic Escherichia coli (DEC) categories isolated from children with acute endemic diarrhea in Salvador, Bahia. The E. coli isolates were investigated by colony blot hybridization with the following genes probes: eae, EAF, bfpA, Stx1, Stx2, ST-Ih, ST-Ip, LT-I, LT-II, INV, and EAEC, as virulence markers to distinguish typical and atypical EPEC, EHEC/STEC, ETEC, EIEC, and EAEC. Seven of the eight categories of DEC were detected. The most frequently isolated was atypical EPEC (10.1%) followed by ETEC (7.5%), and EAEC (4.2%). EHEC, STEC, EIEC, and typical EPEC were each detected once. The strains of ETEC, EAEC, and atypical EPEC belonged to a wide variety of serotypes. The serotypes of the others categories were O26:H11 (EHEC), O21:H21 (STEC), O142:H34 (typical EPEC), and O:H55 (EIEC). We also present the clinical manifestations and other pathogenic species observed in children with DEC. This is the first report of EHEC and STEC in Salvador, and one of the first in Brazil.