Primer reporte de Escherichia coli diarreogénica en población pediátrica ambulatoria con diarrea atendida en la ciudad de La Plata, Argentina / First report of diarrheagenic Escherichia coli in pediatric outpatient population with diarrhea in La Plata, Argentina

Resumen Escherichia coli diarreogénica comprende un grupo heterogéneo de cepas que presentan diversos factores de virulencia y causan diferentes síndromes diarreicos. Los patotipos más estudiados son Escherichia coli enteropatogénica (EPEC), Escherichia coli enterotoxigé-nica (ETEC), Escherichia coli enteroagregativa (EAEC), Escherichia coli enteroinvasiva (EIEC) y Escherichia coli productora de toxina Shiga (STEC). El objetivo de este estudio fue estimar la frecuencia de infección de los diversos patotipos de E. coli diarreogénica en una población pediátrica ambulatoria con diarrea, atendida en el Hospital Sor María Ludovica de La Plata, Argentina, durante el período mayo-octubre de 2017. Los patotipos fueron detectados mediante la amplificación molecular de ocho genes de virulencia característicos. Se estudiaron las heces de 211 ninos (76% menores de 5 años). Se detectó infección con E. coli diarreogénica en el 12,3% (n = 26/211) de los niños con diarrea. Los patotipos identificados fueron EAEC, ETEC (todos lt positivos), EPEC y STEC (stx2 y eae positivos). El patotipo EAEC fue prevalente en todos los grupos etarios, mientras que los patotipos ETEC, EPEC y STEC solamente se observaron en niñnos menores de 5 anños. Este estudio constituye el primer reporte de detección por técnicas de amplificación molecular de Escherichia coli diarreogénica en una población pediátrica ambulatoria con diarrea, de la zona de La Plata. Se necesitan estudios más amplios que incluyan la caracterización de los aislamientos abarcando un mayor número de genes, controles asintomáticos, distintas épocas del ano y población de diversas áreas geográficas para esclarecer la relevancia de la infección por E. coli diarreogénica en niños de Argentina.

Abstract Diarrheagenic Escherichia coli is a heterogeneous group of strains that presents various virulence factors and causes different diarrheal syndromes. The most studied pat-hotypes are enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enteroaggregative Escherichia coli (EAEC), enteroinvasive Escherichia coli (EIEC) and Shiga toxin-producing Escherichia coli (STEC). The objective was to estimate the frequency of infec-tion of diarrheagenic E. coli pathotypes in children with diarrhea, attended at the Sor María Ludovica Hospital in La Plata, Argentina, during the period May-October 2017. E. coli pathotypes were detected by molecular amplification of eight characteristic virulence genes. The feces of 211 children (76% under 5 years) were studied. Infection with diarrheagenic E. coli was detected in 12.3% of the samples. The pathotypes were EAEC (10.43%), ETEC (1.42%, all of them positive for thermolabile toxin), EPEC (0.95%) and STEC (0.47%, positive for Shiga toxin 2). The EAEC pathotype was prevalent in children of all age groups, while ETEC, EPEC and STEC were only observed in children under 5 years of age. This study constitutes the first report of diarrheagenic Escherichia coli detection in an outpatient pediatric population with diarrhea from La Plata, using molecular amplification techniques. Broader future studies, including the charac-terization of the isolates with the largest number of genes, asymptomatic controls, different times of the year and population from different geographic areas will be necessary to clarify the relevance of diarrheagenic E. coli infection in children from Argentina.

Escherichia coli diarrogénicos, identificación de patotipos y fenotipos de resistencia antimicrobiana en aislados cubanos / Diarrheagenic Escherichia coli: identification of pathotypes and antimicrobial resistance phenotypes in Cuban isolates

Introducción: En los países en vías de desarrollo las enfermedades diarreicas agudas son causa frecuente de morbilidad y mortalidad. Entre las primeras causas se encuentra Escherichia coli diarrogénicos, que afecta a pacientes en edades extremas de la vida y con inmunodeficiencias. Objetivo: Identificar los patotipos de Escherichia coli diarrogénicos que más inciden y los fenotipos de resistencia antimicrobiana expresados por el patotipo predominante. Métodos: Se estudiaron 184 aislamientos procedentes de 15 centros provinciales de Higiene, Epidemiología y Microbiología de Cuba e Isla de la Juventud. La investigación se realizó desde julio de 2012 hasta febrero de 2014. La identificación de género, especie y patotipos fue realizada por métodos de diagnóstico convencional y molecular. La determinación de la susceptibilidad antimicrobiana se realizó por el método de Bauer y Kirby, y las normas del Clinical and Laboratory Institute Standards de 2013. Resultados: Se identificaron 108 (58 por ciento) Escherichia coli diarrogénicos. Los patotipos confirmados fueron: en la PCR múltiple 1, 5 (6 por ciento) de Escherichia coli enteropatogénico, 4 (4 por ciento) de enterotoxigénico y 0 (0 por ciento) de enterohemorrágico. La PCR múltiple 2 reveló 72 (82 por ciento) Escherichia coli enteroagregativo, que resultó el predominante en el estudio. La PCR 3 (simple) detectó 7 (8 por ciento) de enteroinvasivo. El 100 por ciento del patotipo predominante mostró resistencia, al menos a un antimicrobiano de los probados, un solo patron de resistencia a dos antimicrobianos, y nueve patrones de multirresistencia. Conclusiones: El estudio demuestra la importancia del uso de pruebas moleculares rápidas para la confirmación de los patotipos de E. coli diarrogénicos, los que provocan deshidratación ligera, complicaciones graves y la muerte. Se logra identificar los cuatro patotipos más frecuentes y E. coli enteroagregativo, el de mayor incidencia en la población estudiada. El patotipo predominante mostró altos porcentaje de resistencia antimicrobiana a betalactámicos y buena sensibilidad antimicrobiana a los aminoglucósidos y cefalosporinas de tercera generación. La investigación aporta conocimientos, no revelados en estudios anteriores con aislados cubanos, lo que es considerado de alto valor para los clínicos, pediatras y epidemiólogos del país(AU)

Introduction: Acute diarrheal disease is a frequent cause of morbidity and mortality in developing countries. One of the leading causes is diarrheagenic Escherichia coli, which affects patients at extreme ages and with immunodeficiencies. Objective: Identify the most active pathotypes of diarrheagenic Escherichia coli and the antimicrobial resistance phenotypes expressed by the prevailing pathotype. Methods: A study was conducted from July 2012 to February 2014 of 184 isolates obtained from 15 provincial Hygiene, Epidemiology and Microbiology Centers in Cuba and the Isle of Youth. Identification of the genus, species and pathotypes was based on conventional and molecular diagnostic methods. Determination of antimicrobial susceptibility was performed by the Bauer-Kirby method in compliance with guidelines from the Clinical and Laboratory Standards Institute of 2013. Results: A total 108 (58 percent) diarrheagenic Escherichia coli were identified. The following pathotypes were confirmed: Multiplex PCR 1 revealed 5 (6 percent) enteropathogenic, 4 (4 percent) enterotoxigenic and 0 (0 percent ) enterohemorrhagic Escherichia coli. Multiplex PCR 2 found 72 (82 percent) enteroaggregative Escherichia coli, which was the prevailing type in the study. PCR 3 (simple) detected 7 (8 percent) enteroinvasive Escherichia coli. 100 percent of the prevailing pathotype displayed resistance to at least one of the antimicrobials tested, a single resistance pattern to two antimicrobials, and nine multiresistance patterns. Conclusions: The study showed the importance of the use of rapid molecular tests to confirm diarrheagenic E. coli pathotypes, which cause mild dehydration, serious complications and death. Identification could be done of the four most common pathotypes and enteroaggregative E. coli, the one with the highest incidence in the study population. The prevailing pathotype displayed high percentages of antimicrobial resistance to beta-lactams and good antimicrobial sensitivity to third-generation cephalosporins and aminoglycosides. The study contributed knowledge not revealed by previous research about Cuban isolates. Such information is considered to be highly valuable for clinicians, pediatricians and epidemiologists in the country(AU)

Presence and antibiotic resistance of diarrheagenic Escherichia coli in ready-to-eat salads / Монголын Анагаах Ухаан

Introduction@#Foodborne diseases are a major public health concern worldwide. The report, which estimates the burden of foodborne diseases – states that each year as many as 600 million, or almost 1 in 10 people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including 125 000 children under the age of 5 years. The 20.3% of diarrhea and 27.5% of die caused by contaminated foods are diarrheagenic Escherichia coli (DEC).@*Aim@#To identify of DEC and determine their antibiotic resistance from ready-to-eat salads@*Material and Methods@#A total of 40 bagged salad mix samples were collected from food markets in Ulaanbaatar, Mongolia. Escherichia coli (E.coli) strains were determined on the basis of MNS 6308:2012 standard and confirmed by polymerase chain reaction (PCR) in samples. DEC was identified using multiplex PCR. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method.@*Results@#Our results showed the presence of E. coli in 19 samples (47.5%). DEC isolates identified by multiplex PCR were defined as follows: the presence of eae and bfp for EPEC, the presence of lt for ETEC, the presence of ipaH for EIEC, the presence of stx1 and stx2 for EHEC, the presence of aap and aggR for EAEC, and the presence of daaE for DAEC. The multiplex PCR assays detected EHEC 6 (31.6%), EPEC 5 (26.3%), EIEC 1 (5.3%). EAEC and ETEC were not detected in samples. The E.coli isolates were 73.7% resistant to chloramphenicol as the first choice of treatment of diarrhea and high resistance (68.4-94.7%) to the cephalosporins. In our country, cephalosporins are widely used in medical practice for the treatment of infectious diseases.@*Conclusion@#In this study, about half of ready-to-eat salads are contaminated with E. coli. The three types (EHEC, EPEC, EIEC) of DEC pathotypes were identified in the ready-to-eat salads and high prevalent of antimicrobial resistance. Future research is required to track the contamination sources and develop appropriate steps that should be taken by industry and retailers to reduce microbial contamination in ready-to-eat salads.

Detection of Enterobacteriaceae, antimicrobial susceptibility, and virulence genes of Escherichia coli in canaries (Serinus canaria) in northeastern Brazil / Detecção de enterobactérias, sensibilidade antimicrobiana e genes de virulência de Escherichia coli em canários belgas (Serinus canaria) da região Nordeste do Brasil

This study aimed to verify the presence of members from the Enterobacteriaceae family and determine antimicrobial susceptibility profiles of the isolates in canaries bred in northeastern Brazil; in addition, the presence of diarrheagenic Escherichia coli (DEC) and avian pathogenic Escherichia coli (APEC) was also verified in these birds. Samples were collected during an exhibition organized by the Brazilian Ornithological Federation in July 2015 in Fortaleza, Brazil. A total of 88 fecal samples were collected and submitted to pre-enrichment step using buffered peptone water, followed by enrichment with the following broths: brain-heart infusion, Rappaport-Vassiliadis, and Selenite-Cystine. Subsequently, aliquots were streaked on MacConkey, brilliant green and salmonella-shigella agar plates. Colonies were selected according to morphological characteristics and submitted to biochemical identification and antimicrobial susceptibility tests with disk-diffusion technique. E. coli strains were evaluated for the presence of eight DEC genes and five APEC genes through conventional polymerase chain reaction (PCR) screening. The most frequent species observed were Pantoea agglomerans (25%), Serratia liquefaciens (12.5%), and Enterobacter aerogenes (9.1%). A single rough strain of Salmonella enterica subsp. enterica was identified in one sample (1.1%). High resistance rates to amoxicillin (78.7%) and ampicillin (75.4%) were identified. Polymyxin B (9.8%), gentamycin (6.6%), and enrofloxacin (6.6%) were the most efficient antibiotics. The total number of multidrug-resistant strains (isolates resistant to more than three antimicrobial classes) was 23 (37.7%). Four E. coli strains were tested for the virulence genes, and two were positive for APEC virulence genes: one strain was positive for iutA and the other for hlyF. In conclusion, canaries in northeastern Brazil participating in exhibitions may present Salmonella spp., Escherichia coli and other enterobacteria in the intestinal microbiota with antimicrobial resistance. These results indicate that, although the E. coli strains recovered from canaries in this study have some virulence genes, they still do not fulfill all the requirements to be considered APEC.(AU)

O objetivo deste trabalho foi verificar a presença de enterobactérias e determinar o perfil de sensibilidade aos antimicrobianos dos isolados oriundos de canários belgas criados em cativeiro do Nordeste do Brasil, adicionalmente verificou-se a presença de Escherichia coli diarreiogênicas (DEC) e E. coli patogênica aviária (APEC) nesses animais. A colheita das amostras ocorreu durante uma exposição de canários belgas organizada pela Federação Ornitológica do Brasil (FOB), em julho de 2015, na cidade de Fortaleza, Ceará, Brasil. Um total de 88 amostras de fezes foram coletadas e submetidas a pré-enriquecimento utilizando água peptonada, caldo de enriquecimento Brain Heart Infusion, Rappaport-Vassiliadis e Selenito-Cistina. Fez-se triagem em placas de ágar MacConkey, Verde Brilhante e ágar Salmonella Shigella. As colônias foram selecionadas e submetidas à identificação bioquímica e susceptibilidade antimicrobiana. Estirpes de Escherichia coli foram avaliadas quanto a presença de 8 genes de virulência de DEC e cinco de APEC por reação em cadeia da polimerase convencional (PCR). As enterobactérias encontradas com maior frequência foram Pantoea agglomerans (25%), Serratia liquefaciens (12,5%) e Enterobacter aerogenes (9,1%). Uma única estirpe de Salmonella enterica subsp. enterica (rugosa) esteve presente em um dos isolados (1,1%). Altos percentuais de resistência foram encontrados para dois antibióticos: amoxicilina (78,7%) e ampicilina (75,4%). Polimixina B (9,8%), gentamicina (6,8%) e enrofloxacina (6,5%) foram os antibióticos com melhor eficiência. O total de estirpes multirresistentes (a mais de três classes de antimicrobianos) foi de 23 (37,7%). Das quatro estirpes de E. coli isoladas, duas foram positivas para os genes de APEC, sendo uma estipe para o gene iss e outra para os genes iutA e hlyF. Portanto, canários belgas criados em cativeiro no Brasil que participam de exposições podem apresentar Salmonella spp., Escherichia coli e outras enterobactérias em sua microbiota intestinal com resistência antimicrobiana. Estes resultados indicam que as estirpes de E. coli isoladas de canário belga no presente estudo apresentam alguns, mas não todos, genes de virulência para serem caracterizadas como E. coli patogênica para aves (APEC).(AU)

Detection of Diarrheagenic Escherichia coli in Bovine Meat in the Northern Region of Paraná State, Brazil

Abstract Ground bovine meat is commonly consumed by the population of Brazil. However, it constitutes an excellent medium for the multiplication of microorganisms due to available nutrients and handling practices prior to consumption. Here, we examined 100 samples of ground beef for the presence of diarrheagenic Escherichia coli (DEC) pathotypes by PCR, and characterized isolates by analyzing their adherence to HEp-2 cells, serotype, antimicrobial susceptibility, and phylogeny. Enteroaggregative E. coli was detected in five (5%) meat samples, Shiga toxin-producing E. coli in three (3%), and atypical enteropathogenic E. coli in two (2%). According to the phylogeny, six isolates (60%) were classified in group A, two (20%) in group B1, and two (20%) in group E. The detected serotypes were O3:H2, O93:H9, O93:H46, O105ab:H7, O152:H8, O156:H10, and O175:H7. The antimicrobial susceptibility testing showed that one sample (10%) was resistant to ampicillin, two (20%) to sulfamethoxazole-trimethoprim, and two (20%) to cephalothin. Based on these results, bovine ground meat for human consumption can serve as a reservoir of DEC, which emphasizes the importance of appropriate hygienic-sanitary conditions during handling at every stage from slaughter to table.

Real-time multiplex polymerase chain reaction with high-resolution melting-curve analysis for the diagnosis of enteric infections associated with diarrheagenic Escherichia coli

Introduction: Although diarrheagenic Escherichia coli (DEC) strains are important bacterial causative agents of diarrhoea, they are not routinely sought as stool pathogens in clinical laboratories as conventional microbiological testing are unable to distinguish between normal flora and pathogenic strains of E. coli. This study was undertaken to determine the prevalence of DEC pathotypes amongst children with and without diarrhoea and to detect specific virulent genes present in different DEC pathotypes, using real-time multiplex polymerase chain reaction (PCR) with high-resolution melting (HRM) technology. Materials and Methods: Stool samples were obtained from cases and controls. Using a set of conventional biochemical tests, E. coli strains were identified. Further, these isolates were subjected to multiplex PCR system for the detection of virulence genes of different pathotypes of DEC. Real-time multiplex PCR was performed for the detection of specific virulent genes of DEC pathotypes, using Rotor-Gene Q instrument (Qiagen) having High-resolution Melt analyser using Type-it HRM PCR kit (Qiagen) containing EvaGreen fluorescent intercalating dye. Results: In this study, we had successfully standardised two multiplex PCR assays which were found to be effective for direct detection of enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC). A total of 42 DEC strains were detected at an overall rate of 19.3% (n = 42), from the total 217 E. coli isolates recovered from the cases (n = 39, 17.9%) and control (n = 3, 3.8%) groups. Amongst the 42 DEC pathotypes (39 from cases and 3 from controls), EPEC (10%), EAEC (8.82%), ETEC (2.94%) and EIEC (1.18%) were found in children with diarrhoea (cases) and in children without diarrhoea (control) only EAEC (2.13%) and EPEC (4.26%) were detected. Age distribution, gender variation, seasonal variation and clinical features were also analysed Conclusion: This study helped evaluate the prevalence of DEC amongst children (<18 years of age) with and without diarrhoea using multiplex real-time PCR with HRM analysis.

Antimicrobial susceptibility and diarrheagenic diagnosis of Escherichia coli and Salmonella enterica isolated from feral pigeons (Columba livia) captured in Fortaleza, Brazil / Isolamento, sensibilidade antimicrobiana e diagnóstico de cepas diarreiogênicas de Escherichia coli e Salmonella enterica isoladas de pombos urbanos (Columba livia) capturados em Fortaleza, Brasil

This study aimed to isolate Escherichia coli and Salmonella enterica from captured feral pigeons in Fortaleza, Brazil, and, in addition to evaluate the antimicrobial susceptibility profiles and diagnose diarrheagenic E. coli strains. Pigeons were captured in four public locations in Fortaleza with three techniques. Individual cloacal swab samples were collected and submitted to bacterial isolation, biochemical identification and antimicrobial susceptibility test. Disk diffusion technique was used with twelve antibiotics. E. coli strains were submitted to DNA extraction followed by PCR to diagnose five diarrheagenic pathotypes. A total of 124 birds were captured. One bird was positive for Salmonella enterica (0.81%) and 121 (97.58%) were positive for E. coli. Among these, 110 isolates were submitted to antimicrobial susceptibility test and 28.18% (31/110) presented resistance to at least one antibiotic. Resistance to azithromycin was the most frequent (21.82%), followed by tetracycline (10.91%) and sulfamethoxazole with trimethoprim (8.9%). Multidrug resistance, calculated as a resistance to at least 3 antimicrobial classes, was identified in 3.64% (4/110) of strains. The maximum number of antimicrobial classes to which one strain was resistant was seven. Results demonstrated nine different resistance profiles and the most frequent was tetracycline and sulfamethoxazole with trimethoprim (4 strains), followed by chloramphenicol, azithromycin, tetracycline and sulfamethoxazole with trimethoprim (3 strains). Amoxicillin with clavulanic acid and tobramycin presented lowest levels of antimicrobial resistance, to which none of the tested strains were resistant. A single strain was positive for the eltB gene, which is a diagnostic tool to identify the Enterotoxigenic E. coli (ETEC) pathotype. None of the other investigated genes (stx1, stx2, estA, eaeA, ipaH, aatA and aaiC) were identified. The single isolate of S. enterica was a rough strain of Salmonella enterica subsp. enterica, but serotype identification was not possible. However, this isolate presented resistance to amoxicillin, amoxicillin with clavulanic acid, tetracycline and sulfamethoxazole with trimethoprim. Therefore, captured feral pigeons of Fortaleza presented a low prevalence of S. enterica and diarrheagenic E. coli. Considering the investigated pathogens, our results suggest a good health status and a low public health risk. However, important antimicrobial resistance profiles were identified.(AU)

O objetivo deste estudo foi isolar cepas de Escherichia coli e Salmonella enterica de pombos urbanos capturados em Fortaleza, Brasil, e avaliar os perfis de resistência antimicrobiana dos isolados, bem como diagnosticar patotipos diarreiogênicos de E. coli. Pombos foram capturados em quatro locais públicos de Fortaleza utilizando três técnicas. Amostras individuais de suabes cloacais foram coletadas e submetidas a isolamento bacteriano, seguido de identificação bioquímica e teste de susceptibilidade a antimicrobianos. A técnica de disco difusão foi utilizada para avaliar resistência antimicrobiana a doze antibióticos. Cepas de E. coli foram submetidas à extração de DNA seguido de PCR para o diagnóstico de cinco patotipos diarreiogênicos. Um total de 124 aves foram capturadas, a partir das quais em uma houve isolamento de Salmonella enterica (0,81%) e em 121 (97,58%) houve isolamento de E. coli. Destas, 110 isolados foram submetidos a teste de suscetibilidade a antimicrobianos e 28,18% (31/110) apresentaram resistência a pelo menos um antibiótico. Resistência a azitromicina foi a mais frequente (21,82%), seguida por tetraciclina (10,91%) e sulfametoxazol com trimetoprim (8,9%). Resistência a múltiplas drogas foi identificada em 3,64% (4/110) dos isolados e o número máximo de antibióticos aos quais uma única cepa foi resistente foi sete. Resultados demonstraram nove diferentes perfis de resistência e o mais frequente foi tetraciclina e sulfametoxazol com trimetoprim (4 cepas), seguido por cloranfenicol, azitromicina, tetraciclina e sulfametoxazol com trimetoprim (3 cepas). Amoxicilina com ácido clavulânico e tobramicina foram os antibióticos com menor resistência antimicrobiana, aos quais nenhuma cepa apresentou resistência. Uma única cepa foi positiva para o gene eltB que é usado para diagnóstico do patotipo E. coli enterotoxigênica (ETEC), enquanto que os demais genes investigados (stx1, stx2, estA, eaeA, ipaH, aatA e aaiC) não foram identificados. A única cepa de S. enterica isolada foi identificada como uma cepa rugosa de Salmonella enterica subsp. enterica e, portanto, a identificação do sorotipo não foi possível. Entretanto, este isolado apresentou resistência a amoxicilina, amoxicilina com ácido clavulânico, tetraciclina e sulfametoxazol com trimetoprim. Portanto, pombos urbanos capturados em Fortaleza apresentaram baixa prevalência de cepas de S. enterica e E. coli diarreiogênicas. Considerando os patógenos investigados, os resultados encontrados sugerem um bom status sanitário destas aves e um baixo risco à saúde pública. Entretanto, importantes perfis de resistência antimicrobiana foram identificados.(AU)

Identificação molecular de Escherichia coli diarreiogênica na Bacia Hidrográfica do Rio Xopotó na região do Alto Rio Doce / Molecular identification of diarrheagenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Brazil

RESUMO Esta pesquisa científica teve como principal objetivo identificar patótipos de Escherichia coli diarreiogênica nas águas superficiais da Bacia Hidrográfica do Rio Xopotó, na região do Alto Rio Doce, Minas Gerais. Os estudos referentes às estirpes diarreiogênicas de E. coli no meio ambiente no Brasil são escassos. A bacia hidrográfica escolhida para o estudo sofre intensa degradação ambiental devido ao lançamento de esgoto in natura em seus corpos d'água e às atividades antrópicas, como a agropecuária. As coletas de água nos 13 pontos amostrais foram realizadas em duas épocas do ano de 2015 (abril e julho). Para identificação dos genes de E. coli diarreiogênica, utilizou-se o método de reação em cadeia da polimerase (PCR). A bacia hidrográfica apresentou contaminação diarreiogênica de patótipos E. coli produtora de toxina Shiga (STEC), E. coli enteropatogênica (EPEC) e E. coli enterotoxigênica (ETEC), tal ocorrência foi constante em ambas as campanhas. Os genes de virulência observados foram: na STEC, toxina Shiga (Stx1), responsável por causar doenças renais graves, como a síndrome hemolítico-urêmica (SHU); já a EPEC apresentou somente o gene virulento eae, característico do subgrupo atípico (aEPEC); a ETEC apresentou toxinas termolábeis (LT). A presença desses patótipos representa potencial risco de doenças diarreiogênicas na população que utiliza os recursos hídricos, particularmente idosos e crianças, e evidencia o comprometimento da qualidade microbiológica dos cursos d'água constituintes da Bacia Hidrográfica do Rio Xopotó, decorrente principalmente da ausência de estações de tratamento de esgoto (ETEs).

ABSTRACT The main purpose of this scientific research was to identify pathotypes of diarrheogenic Escherichia coli in the watershed of Xopotó River, in Alto do Rio Doce, Minas Gerais region, Brazil. The studies referring to the stirps diarrheagenics of E. coli in the environment in Brazil are scarce. The watershed chosen for the study suffers intense environmental degradation due the release of raw sewage into their water bodies and human activities, such as agriculture. The water collecting at 13 sampling points were held in two periods of the year 2015 (April and July). For the identification of the genes of diarrheagenic E. coli, the method of reaction polymerase chain (PCR) was used. The watershed presented pathogenic contamination of pathotypes Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC) such a constant occurrence in both campaigns. The virulence genes observed were: STEC, Shiga toxin (Stx1), responsible for causing severe kidney disease as hemolytic-uremic syndrome (HUS). Besides that, EPEC presented only the virulent gene eae, characteristic of the atypical subgroup (aEPEC), as well as thermolabile toxins (LT). The presence of these pathotypes represents potential risk of diarrheagenic diseases in the population that uses the water resources, particularly the elderly and children, and demonstrates the commitment of the microbiological quality of constituents watercourses of the watershed of Xopotó River, mainly because the lack of sewage treatment facilities.

Monitoring of diarrheagenic Escherichia coli infections in patients in Guangdong Province during 2013 to 2016 / 中华微生物学和免疫学杂志

Objective To investigate the infection status, serotype distribution, drug sensitivity and molecular characteristics of diarrheagenic Escherichia coli (DEC) in patients with diarrhea in Guangdong Province. Methods Fecal samples were collected, cultured and isolated by traditional methods. Suspected Escherichia coli isolates were confirmed by multiplex PCR used for detecting specific virulence genes and bio-chemical methods. Positive strains were serotyped, characterized for drug sensitivity and analyzed by pulsed-field gel electrophoresis ( PFGE). Results The total positive rate of DEC in patients with diarrhea was 6.26%. The positive rates of enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enterohemorrhagic Escherichia coli (EHEC), enteroadherent Escherichia coli (EAEC) and en-teroinvasive Escherichia coli (EIEC) were 2. 47% , 1. 54% , 1. 32% , 0. 62% and 0. 09% , respectively, with infections primarily in children aged 0-<7 years. The total seropositive rate was 52. 54% , with EHEC accounting for 15. 00% . DEC showed high sensitivity to imipenem, ciprofloxacin, ceftazidime and cefo-taxime. The multidrug resistance rate of DEC was 58. 45% , with EPEC being the most serious for multidrug resistance. PFGE results showed that ETEC, EHEC, EPEC and EAEC had a high degree of polymorphism. Conclusion EPEC is the predominant type of DEC circulating in Guangdong Province. Third-generation cephalosporins are the first drugs of choice for treating infections in children. Ciprofloxacin can be used to treat adults. The problem of multiple drug resistance of DEC is severe and efforts to monitor DEC infections and drug resistance should be strengthened.

A case-control study on diarrheagenic E .coli infection in children / 中华传染病杂志

Objective To understand the regional epidemiology and antibiotic resistance pattern of diarrheagenic E .coli infection in children ,and to clarify the pathogenic association between diarrheagenic E .coli infection and childhood diarrhea .Methods Totally 680 diarrheal children in the outpatient setting and 680 non-diarrheal control children were enrolled prospectively .The stool samples were collected and the potential enteric pathogens were detected .Minimal inhibitory concentration (MIC) method was used to determine the antimicrobial susceptibility for diarrheagenic E .coli isolates .Results The isolation rates of diarrheagenic E .coli in diarrhea group and control group were 15 .6％ and 13 .1％ ,respecitvely ,and diarrheagenic E .coli was the most commonly detected enteric bacteria .Multivariate logistic regression analysis adjusted for age suggested no clinical association between diarrhea and infection with enteropathogenic E .coli (EPEC) (aOR=1 .2 ,95％ CI:0 .8-1 .8) ,enteroadhesive E .coli (EAEC) (aOR=1 .1 ,95％ CI:0 .7 -1 .6) and enterotoxigenic E .coli (ETEC) (aOR= 1 .8 ,95％ CI:0 .5 -6 .2) . Among 199 diarrheagenic E .coli strains ,the rates of resistance to ampicillin ,tetracycline ,trimethoprim-sulfamethoxazole ,azithromycin ,and ceftriaxone were 63 .8％ ,55 .8％ ,48 .2％ ,34 .2％ and 26 .6％ , respectively ,while the rates of resistance to ciprofloxacin , amoxicillin-clavulanate and cefoxitin were 4 .5％ ,1 .5％ and 0 .5％ ,respectively .Conclusions Diarrheagenic E .coli is the most common enteric bacteria detected in the stool samples from children with and without diarrhea in this study . The pathogenic role of infections with EPEC ,EAEC and ETEC in childhood diarrhea is not determined .EHEC and EIEC are rarely detected and further studies are needed to clarify the pathogenic association between infection with EHEC ,EIEC and childhood diarrhea .

Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)

ABSTRACT Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli.

Placental and colostral transfer of antibodies reactive with enteropathogenic Escherichia coli intimins α, ß, or γ / Transferência placentária e colostral de anticorpos reativos a Escherichia coli enteropatogênica com expressão das intiminas α, ß, or γ

Abstract Objective: Intimins are protein adhesins of enteropathogenic Escherichia coli and enterohemorrhagic E. coli capable of inducing attachment and effacement lesions in enterocytes. Anti-intimin antibodies are important for the protection from enteropathogenic E. coli and enterohemorrhagic E. coli infections because these antibodies inhibit bacterial adhesion and impair the initial step of the pathogenesis. We studied the transfer of maternal anti-intimin antibodies from healthy Brazilian mothers to their newborns through the placenta and colostrum. Methods: Serum immunoglobulin G and secretory immunoglobulin A antibodies against conserved and variable regions of intimins α, β, and γ were analyzed using an enzyme linked-immunosorbent assay in the blood and colostrum from 45 healthy women as well as cord blood serum samples from their newborns. Results: The concentrations of antibodies reactive with α intimin were significantly lower than those of anti-γ and anti-conserved intimin antibodies in the colostrum samples. IgG serum antibodies reactive with all the subtypes of intimins were transferred to the newborns, but the concentrations of anti-conserved intimin serum antibodies were significantly higher in mothers and newborns than concentrations of antibodies against variable regions. The patterns of IgG transfer from mothers to newborns were similar for all anti-intimin antibodies. These values are similar to the percentage transference of total IgG. Conclusions: Anti-intimin antibodies are transferred from mothers to newborns through the placenta, and reinforce the protection provided by breastfeeding against diarrheagenic E. coli infections.

Resumo Objetivo: As intiminas são adesinas proteicas de Escherichia coli enteropatogênicas (EPEC) e enterro-hemorrágicas (EHEC) capazes de induzir as lesões attaching and effacing nos enterócitos. Anticorpos anti-intiminas são importantes para a proteção contra infecções por EPEC e EHEC porque esses anticorpos inibem a adesão bacteriana e impedem o passo inicial do mecanismo patogênico dessas bactérias. Nós estudamos a transferência de anticorpos maternos anti-intiminas de mães brasileiras saudáveis para os seus recém-nascidos através da placenta e do colostro. Métodos: Anticorpos séricos da classe IgG e secretórios da classe IgA (SIgA) reativos com as porções conservada (cons) e variáveis das intiminas α (vα), β (vβ) e γ (vγ) foram analisados pelo teste de ELISA no sangue e no colostro de 45 parturientes saudáveis e no sangue de cordão umbilical dos seus respectivos recém-nascidos. Resultados: As concentrações de anticorpos reativos com intimina vα foram significativamente mais baixas que as dos anticorpos anti-vγ e anti-cons nas amostras de colostro. Anticorpos IgG séricos reativos com todas as intiminas foram transferidos para os recém-nascidos, mas as concentrações de anti-cons foram significativamente mais altas tanto nas mães como nos recém-nascidos do que os anticorpos reativos com as regiões variáveis das intiminas. O padrão de transferência de IgG das mães para os recém-nascidos foi muito semelhante para todos os anticorpos anti-intiminas. Os valores de porcentagem de transferência foram semelhantes à transferência de IgG total. Conclusões: Anticorpos anti-intimina são transferidos das mães para os recém-nascidos pela placenta e corroboram a proteção contra infecções por Escherichia coli diarreiogênicas (DEC) conferida pelo aleitamento materno.

Detección molecular de Escherichia coli diarreogénica en pacientes pediátricos con síndrome diarreico agudo en Paraguay / Molecular detection of diarrheogenic Escherichia coli in pediatric patients with acute diarrheal syndrome in Paraguay

La Escherichia coli diarreogénica (ECD) se ha clasificado con base en criterios clínicos, epidemiológicos y moleculares en cinco grupos, cada uno con factores de virulencia específicos. El objetivo fue determinar la prevalencia de ECD en pacientes pediátricos con enfermedad diarreica aguda del Laboratorio Central de Salud Publica en el periodo 2012- 2015. Se procesaron muestras de heces con síndrome diarreico agudo, provenientes de pacientes pediátricos, en los cuales se buscó algún gen de virulencia ECD utilizando métodos convencionales de siembra y screening molecular, mediante PCR múltiple con cebadores diseñados específicamente para amplificar los genes de virulencia elt, est, eae, stx, ipaH y aggR. Del total de muestras analizadas, 13% (180/1379) de las muestras presentó algún factor de virulencia compatible con algún patotipo ECD con mayor predominio en niños de 1 a 3 años. La frecuencia de los distintos patotipos fue la siguiente: 61 (34%) ETEC, 40 (22%) EAEC, 41 (23%) EPEC, 27 (15%) EIEC, 7 (4%) STEC y 3 (2%) ETEC/EAEC, 1 (0.5%) ETEC/EAEC/EIEC. El porcentaje de E. coli diarreogénicas detectado tiene similitud con lo reportado en otros países de la región, lo que nos indica que estos patógenos son parte importante de la etiología de la enfermedad diarreica aguda infecciosa en la población infantil en nuestro país. Se debe destacar que para el diagnóstico de las diferentes categorías ECD, es necesario disponer de un procedimiento diagnóstico específico dirigido a la detección de los factores de virulencia utilizando métodos moleculares o métodos inmunológicos.

Diarrheagenic Escherichia coli (DEC) has been classified based on clinical, epidemiological and molecular criteria in five groups, each with specific virulence factors. The objective was to determine the prevalence of DEC in pediatric patients with acute diarrheal disease of the Central Laboratory of Public Health in the 2012-2015 period. A total of 1447 fecal samples of acute diarrheal syndrome from pediatric patients were processed in which a DEC virulence gene was searched using conventional screening and molecular screening methods with multiple PCR primers specifically designed to amplify virulence genes, st, lt, eae, stx, ipaH and aggR. From the total of analyzed samples, 13% (180/1379) of the samples presented some virulence factor compatible with a DEC pathogen type with greater predominance in children from 1 to 3 years. The frequency of the different pathogen types was as follows: 61 (34%) ETEC, 40 (22%) EAEC, 41 (23%) EPEC, 27 (15%) EIEC, 7 (4%) STEC and 3 (2% ETEC/EAEC, 1 (0.5%) ETEC/EAEC/EIEC. The percentage of DEC detected is similar to that reported in other countries of the region, which indicates that these pathogens are an important part of the etiology of acute infectious diarrheal disease in children in our country. It should be noted that for the diagnosis of different DEC categories, it is necessary to have a specific diagnostic procedure aimed at the detection of virulence factors using molecular methods or immunodiagnostic methods.

Perfil de susceptibilidade antimicrobiana e identificação de patotipos diarreiogênicos entre amostras de Escherichia coli isoladas de alimentos / Antimicrobial susceptibility profile and identification of pathotypes diarrheagenic between Escherichia coli strains isolated from food

O presente estudo objetivou avaliar o perfil de susceptibilidade antimicrobiana e a ocorrência de patotipos diarreiogênicos (E. coli entoropatogênica/EPEC, E. coli enterotoxigênica/ETEC, E. coli produtora de shiga toxina/STEC, E. coli enteroinvasiva/EIEC e E. coli enteroagregativa/EAEC) em amostras de Escherichia coli, isoladas de diversos alimentos destinados ao consumo humano e naqueles envolvidos em surtos de Doença de Transmissão Alimentar (DTA), em Minas Gerais, Brasil. O perfil de susceptibilidade antimicrobiana das amostras de E. coli foi avaliado por meio da técnica de Concentração Mínima Inibitória e os patotipos de E. coli diarreiogênica pela Reação em Cadeia de Polimerase, utilizando-se os marcadores de virulência eae, bfpA, eltB, estA, st1, stx1, stx2, ipaH e aatA. Dentre as 220 amostras de E. coli analisadas, 60 (27,3%) apresentaram-se resistentes ou com resistência intermediária. Entre estas, oito (13,3%) foram consideradas multirresistentes. Os fármacos amicacina e gentamicina foram os mais eficazes, diferentemente da ampicilina, que apresentou o maior percentual de amostras resistentes (10,9%). Não foram identificados os patotipos de EPEC, STEC, EIEC e EAEC. Duas amostras de E. coli (0,9%), isoladas de um salgado (pão de queijo) e de uma refeição mista (galinhada), foram classificadas como ETEC. Ambas albergavam os marcadores de virulência eltB, estA e st1. Estas foram caracterizadas como pertencentes sorotipos O9:H10 e O9:H33. Conclui-se que entre as amostras de E. coli, isoladas de alimentos destinados ao consumo humano em Minas Gerais e naqueles envolvidos em surtos de DTA, existem de amostras consideradas multirresistentes e diarreiogênicas.

This study aimed to evaluate the profile of antimicrobial susceptibility and the occurrence of diarrheagenic pathotypes (E. colientoropatogênic/EPEC, E. coli enterotoxigenic/ETEC, E. coli producing shiga toxin/STEC, E. coli enteroinvasive/EIEC and E. colienteroaggregative/EAEC) in Escherichia coli isolated from different foods intended for human consumption and those involved in foodborne disease outbreaks, in Minas Gerais, Brazil. The antimicrobial susceptibility of strains of E. coli was evaluated by the Minimum Inhibitory Concentration technique and pathotypes of E. coli diarrheagenic by polymerase chain reaction, using the virulence markers eae, bfpA, eltB, st1, stx1, stx2, ipaH and aatA. Among the 220 strains of E. coli analyzed, 60 (27.3%) were resistant or intermediate resistance. Among these, eight (13.3%) were considered multiresistant. The amikacin and gentamicin drugs were the most effective, unlike ampicillin, which had the highest percentage of resistant strains (10.9%). Pathotypes of EPEC, STEC, EIEC and EAEC were not identified. Two strains of E. coli (0.9%) isolated from a salty (cheese bread) and a mixed meal (chicken meal) were classified as ETEC. Both harbored the virulence markers eltB, estA and st1. These were characterized as serotypes O9:H10 and O9:H33. We conclude that among samples of E. coli, isolated from foods for human consumption in Minas Gerais and those involved in outbreaks of DTA, there are samples considered multiresistant and diarrheogenic.

Surveillance of diarrheagenic Escherichia coli infection in Yanping and Yongan, Fujian Province, China / 中国人兽共患病学报

We investigated the epidemiological characteristics of diarrheagenic Escherichia coli (E.coli) infection in Fujian Province,providing reference for the prevention and control of diarrhea epidemic and outbreak.Yanping and Yongan areas were selected as surveillance sites from year 2010 to 2015,where 1 950 samples were collected from the sentinel hospitals,and then samples were isolated and cultured on MacConkey agar plates.Suspected strains were identified by routine and molecular diag nosis technique methods.Results were analyzed by SPSS 17.0 software package.A total of 129 strains of diarrheagenic E.coli were isolated with a total detection rate of 6.62％.The detection rates of enteropathogenic E.coli(EPEC),enterotoxigenic E.coli(ETEC) and enteroadhesive E.coli(EAEC) were 3.33％,1.64％ and 1.64％ respectively (including 61 strains of atypical EPEC,4 strains of typical EPEC,and 32 strains of ETEC and EAEC for each),while EHEC and EIEC were not found.There was no significant difference between the detection rates of male and female.All the patients were divided into five groups according to the age,and there were no significant differences between the detection rates of EPEC,EAEC and ETEC in the 5 groups.The detection rates were the highest in August and September.There was no significant difference between the detection rates of rural area and uban area.There was also no significant difference between the composition ratio of diarrheagenic E.coli (DEC) in the two surveillance sites.In conclusion,there were three kinds of DEC in Fujian Province,and EPEC was the dominant.August and September were the months with the highest detection rates.Children age less than five and adult aged 20 59 years were the high risk groups with DEC infection.More attention should be attached on the rational treatment by antibiotic for DEC.

Flooding adds pathogenic Escherichia coli strains to the water sources in southern Khyber Pakhtunkhwa, Pakistan.

Purpose: Seasonal rains in Pakistan result in heavy floods across the country, whereby faecal contaminants will be added to the water bodies and cause numerous food‑borne outbreaks. The present study was aimed to determine the prevalence of diarrheagenic Escherichia coli (DEC) strains in the water sources. Materials and Methods: Two hundred water samples collected during (2011–2012) were processed for the isolation of E. coli (EC) strains. EC strains were further analysed for antibiotic susceptibility patterns, and pathogroups‑specific virulence factors stx1, stx2, stx2c, eae, tir, hlyA, bfpA, estA and eltA were detected using multiplex polymerase chain reaction. Results: Thirty‑three percent of the water samples were contaminated with EC pathotypes. Fifty percent (33/66) of the DEC pathotypes were identified as enterotoxigenic EC (ETEC). Seventy‑two percent (13/18) of the enteropathogenic EC (EPEC) strains were identified as typical EPEC and 28% (5/18) as atypical EPEC. Eleven percent (7/66) of the Shiga toxin EC (STEC) isolates carried a combination of stx1 and stx2 genes. Summer was found as a peak season with 47% (31/66) for EC pathogroups’ activities. Eighty‑nine percent of the strains showed resistance against tetracycline. Conclusion: ETEC and EPEC are the primary causes of water contamination in southern regions of Khyber Pakhtunkhwa province, Pakistan. Firm adherence to the prescribed drugs can decrease trends in antibiotic resistance.

Pathogenic detection of infectious diarrhea in patients in a district of Beijing from 2011 to 2013 / 中国感染控制杂志

Objective To analyze the distribution and pulsed-field gel electrophoresis (PFGE)of pathogenic bacteria causing infectious diarrhea in a district of Beijing from 2011 to 2013,and provide basis for tracing infection sources.Methods A total of 1 179 stool specimens of infectious diarrhea from patients in a diarrhea outpatient department from January 2011 to December 2013 were collected,all isolated pathogens were identified by serotyping and PFGE analysis.Results 330 enteric pathogens were isolated from 1 179 specimens,the top 4 bacteria were Shi-gella spp .(28.18%,n=93),Salmonella spp .(20.91 %,n=69),Vibrio parahaemolyticus (13.33%,n =44),and diarrheagenic Escherichia coli (3.33%,n = 11 ).18 Shigella sonnei isolates were identified as 8 PFGE patterns, clustering similarity was close to 88%;69 Salmonella spp .strains belonged to 18 serotypes and 41 PFGE patterns, Salmonella senftenberg and Salmonella enteritidis had dominant patterns;no dominant PFGE patterns were obviously identified among 23 strains ofVibrio parahaemolyticus .Conclusion The serotypes and PFGE patterns of pathogenic bacteria in infectious diarrhea in past three years showed a wide distribution characteristics,the dominant PFGE patterns of Salmonella spp .and Shigella spp .need to be paid more attention,and outbreak of infectious diarrhea caused by Salmonella spp .and Shigella spp .should be alerted.

Clinical and etiologic features of diarrheagenic Escherichia coli-associated diarrhea in children / 中华传染病杂志

Objective To investigate the pathotypes,epidemiological characteristics and antimicrobial resistance of diarrheagenic Escherichia coli (DEC) in children with acute bacterial diarrhea in Shanghai.Methods A total of 2 071 outpatient children with probable acute bacterial diarrhea referred to the enteric clinic of Children's Hospital of Fudan University during June 2012 to June 2014 were enrolled in our study.The stool samples were processed for routine microbiologic and biochemistry tests to identify enteric bacteria,including enteropathogenic Escherichia coli (EPEC),enterotoxigenic Escherichia coli (ETEC),enteroinvasive Escherichia coli (EIEC) and enterohemorrhagic Escherichia coli (EHEC).Kirby-Bauer method was used to identify the antibiotic sensitivity.Difference of means between groups was compared by chi-square test.Results Of 2 071 enrolled children,DEC were identified in 145 (7.0 ％)cases.148 strains were isolated with three of mix infection strains.All DEC isolates in this study included 106 (71.6％) EPEC,24 (16.2％) ETEC,16(10.8％) EIEC and 2(1.4％) EHEC.The median ages of diarrheal children with DEC infections were 14 months (range:3 months to 13 years) and 62.8％ of them were ＜2 years.Among 125 DEC isolates tested for antimicrobial susceptibility,the rates of resistance to ampicillin,trimethoprim-sulfamethoxazole,cefotaxime,cefepime,gentamicin,ceftazidime,amoxicillinclavulanate,ciprofloxacin,and ofloxacin in a descending order were 55.2％,35.2％,28.0％,27.2％,23.2％,8.8％,5.6％,4.0％ and 4.0％,respectively.Resistance rates of EIEC to cefotaxime,cefepime and ceftazidime were 50.0％,43.8％ and 25.0％,respectively,which were higher than those of EPEC,ETEC and EHEC.Conclusion DEC is the important enteric bacteria that causes bacterial diarrhea in children in this study.

Study of a multiplex PCR method for the detection of three Diarrheagenic Escherichia coli / 国际检验医学杂志

Objective To establish a multiplex polymerase chain reaction (PCR) method for rapid detection of three kinds of di‐arrheagenic Escherichia coli(EPEC ,EIEC ,EHEC)simultaneously .Methods The eae gene of EPEC ,ipaH gene of EIEC and stx1 gene of EHEC were selected to design primers ;the reaction system and condition were adjusted to optimize the multiplex PCR sys‐tem .Results The target gene fragments were amplified correctly with these primers .The three target bacteria could be detected at the same time by multiplex PCR .Conclusion A rapid multiplex PCR system were successfully established for detection of three di‐arrheagenic Escherichia coli ,and this system could be suitable for rapid screening in food safety .

Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing / 中华流行病学杂志

Objective To understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing. Methods Stool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program,during 2012-2013. DNA was examined by real-time PCR. Results 253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection,were isolated from 9 specimens. Different pathotypes would show the following profiles:42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical;38.9% for enterotoxigenic E. coli(ETEC)including 24.8%st positive,9.9%lt positive and 4.2%st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli(EIEC);one strain STEC with serotype O26 ∶ K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation. Conclusion DEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC,with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.