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1.
Rev. argent. microbiol ; 56(1): 3-3, Mar. 2024.
Article Dans Espagnol | LILACS-Express | LILACS | ID: biblio-1559278

Résumé

Resumen Escherichia coli diarreogénica abarca un grupo heterogéneo de patotipos o variantes patogénicas que comparten características fenotípicas con marcadas diferencias en genes de virulencia, sitios de colonización, patogenia, presentación clínica y epidemiología de la infección. Los patotipos más estudiados son E.coli productora de toxina Shiga (STEC), E.coli enterotoxigénica (ETEC), E.coli enteropatogénica (EPEC), E.coli enteroagregativa (EAEC) y E.coli enteroinvasiva (EIEC). El objetivo del estudio fue caracterizar los aislamientos de E.coli diarreogénica provenientes de población pediátrica ambulatoria con diarrea, atendida en dos hospitales públicos de Buenos Aires, Argentina. Los patotipos de E.coli diarreogénica se investigaron mediante la amplificación de fragmentos de genes de virulencia característicos: intimina (eae), toxina termolábil (lt), toxinas termoestables (stp, sth), antígeno plasmídico de invasiónH (ipaH), activador transcripcional R (aggR) y toxinas Shiga (stx1, stx2). La subtipificación molecular de aislamientos se realizó mediante PFGE (XbaI). E.coli diarreogénica fue detectada en el 14% (84/601) de los casos. El patotipo EAEC fue prevalente, mientras que ETEC, STEC, EPEC y EIEC fueron hallados en menor proporción. Los aislamientos de EAEC presentaron un alto grado de diversidad genética. Todos los patotipos fueron hallados en niños menores de 5años, mientras que solamente EAEC, EIEC y ETEC fueron detectados en población de mayor edad. Futuros estudios que incluyan la caracterización de aislamientos a partir de un mayor número de genes y población de otras áreas geográficas serán necesarios para determinar la relevancia de E.coli diarreogénica en Argentina.


Abstract Diarrheagenic Escherichia coli comprises a heterogeneous group of pathotypes or pathogenic variants that share phenotypic characteristics with marked differences in virulence genes, colonization sites, pathogenesis, clinical presentation, and epidemiology of infection. The most studied pathotypes are Shiga toxin-producing E.coli (STEC), enterotoxigenic E.coli (ETEC), enteropathogenic E.coli (EPEC), enteroaggregative E.coli (EAEC), and enteroinvasive E.coli (EIEC). The objective of the study was to characterize the isolates of diarrheagenic E.coli from an outpatient pediatric population with diarrhea attended in two public hospitals from Buenos Aires, Argentina. Diarrheagenic E.coli pathotypes were investigated by amplifying characteristic virulence gene fragments: intimin (eae), heat-labile toxin (lt), heat-stable toxins (stp, sth), invasion plasmid antigen H (ipaH), transcriptional activator R (aggR) and Shiga toxins (stx1, stx2). Molecular subtyping of isolates was performed using PFGE (XbaI). Diarrheagenic E.coli was detected in 14% (84/601) of cases. The EAEC pathotype was prevalent, while ETEC, STEC, EPEC and EIEC were found in a lower proportion. EAEC isolates exhibited a high degree of genetic diversity. All pathotypes were found in children under 5years of age, while only EAEC, EIEC and ETEC were detected in the older population. Future studies that include the characterization of isolates from a greater number of genes and populations from other geographical areas will be necessary to determine the relevance of diarrheagenic E.coli in Argentina.

2.
Malaysian Journal of Microbiology ; : 159-166, 2020.
Article Dans Anglais | WPRIM | ID: wpr-823245

Résumé

@#Aims: Pathogenic Escherichia coli is one of global concern because of their effect on public health. The aims of this study were to determine the prevalence of E. coli, i.e. enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorragic E. coli (EHEC), and enteroinvasive E. coli (EIEC) in ice-based beverages sold in street food vendors in Bogor and to determine virulence factor and quantity of labile toxin (LT), stable toxin (ST), intimin (EAE), shiga-like toxin1 (STX1), shiga-like toxin 2 (STX2), and plasmid invasion (INV). Methodology and results: Identification and quantification of pathogenic E. coli in ice-based beverages (n=85) were performed using real-time PCR (RT-PCR) assay adding propidium monoazide (PMA) prior to samples extraction. Extracted samples were analyzed using electrophoresis gel to define positive genome. The analyzed result showed 55.3% samples were positive genome and those samples were analyzed using RT-PCR to define virulence factor and determined concentration of bacteria. The result showed virulence factor of pathogenic on ice-based beverages (pudding with coconut milk ice, flavored ice, mix fruits ice, coconut ice, and orange ice) were only labile toxin (LT). The prevalence value was 8.2% with varied cycle threshold (Ct) numbers between 28.2 ± 0.3 to 32.8 ± 3.0 and the melting temperature (Tm) was 78.5 °C. The enterotoxigenic E. coli (ETEC) concentration in samples were 1.8101 -2.0102 cells/mL. Conclusion, significance and impact study: Iced-based beverage samples in Bogor contained 8.2% of ETEC. Based on the consumption data and the concentration of ETEC in iced-based beverages, the number of ETEC exposure in icebased beverages consumed by the consumer in Bogor (2.9103 -2.4104 cells) was lower than infection dose set by FDA. However, this result could be considered as an early warning of health problems.

3.
Pesqui. vet. bras ; 36(4): 253-257, tab
Article Dans Anglais | LILACS | ID: lil-787570

Résumé

The aim of this study was to assess the frequency and association of virulence factors of Escherichia (E.) coli isolated from weaned piglets with diarrhea and to correlate it with fecal consistency. A total of 152 rectal swabs were collected from 25-40 day-old piglets with diarrhea, in farms of Southern Brazil. Phenotypical and molecular techniques were used for bacterial isolation, characterization and classification of enterotoxigenic E. coli (ETEC) pathotypes. Statistical analysis was carried out to determine the frequency of virulence factors and virotypes, of fimbriae F4, F5, F6, F18, F41 and toxins LT, STa, STb and STx2e. Out of 456 E. coli isolates, 287 (62.9%) samples showed significant growth of E. coli. Among them, 194 (67.6%) samples showed at least one virulence factor, indicating that ETEC is an important etiological agent of diarrhea in weaned piglets. Higher frequencies were found of fimbria F4 and F18 and enterotoxins LT, STa and STb. Significant association was found to F4, LT, STa and STb; between F18 and STa and STx2e; between F5 and LT, STa and STb. The most frequent virotypes were F18-STa, F4-LT-STa-STb, F4-STa, F4-LT-STb and F18-STa-STx2e. Beta-hemolysis was observed in 47.4% of samples and there was significant association between hemolytic samples and virulence factors F4, F18, STa and STx2e. Regarding fecal consistency, there was significant association of liquid feces and F4 fimbria, STa toxin and virotypes F4-STa and F4-F5-LT-STa-STb. Since there was significant association of ETEC and liquid feces in nursery piglets, it is important to prioritize the sampling of liquid feces for the diagnosis etiologic cause of diarrhea.


O objetivo deste estudo foi avaliar a frequência e associação de fatores de virulência de Escherichia (E.) coli isoladas de leitões desmamados com diarreia e correlacioná-la com consistência fecal. Suabes retais foram coletados em leitões com 25-40 dias de idade com sinal clínico de diarreia, em granjas do Sul do Brasil, totalizando 456 amostras. Foram utilizadas técnicas fenotípicas e moleculares para isolamento bacteriano, caracterização e classificação de patotipos de E. coli enterotoxigênica (ETEC). A análise estatística foi realizada para determinar a frequência de fatores de virulência e virotipos, de fímbrias F4, F5, F6, F18, F41 e toxinas LT, STa, STB e STx2e. Duzentas e oitenta e sete (62,9%) amostras apresentaram crescimento significativo de E. coli. Entre os quais, 194 (67,6%) amostras apresentaram pelo menos um fator de virulência, indicando que ETEC é um importante agente etiológico de diarreia em leitões desmamados. As frequências mais elevadas foram encontradas para as fímbrias F4 e F18 e enterotoxinas LT, STa e STb. Associação significativa foi encontrada para F4, LT, STa e STb; entre F18 e STa e STx2e; entre F5 e LT, STa e STb. Os virotipos mais frequentes foram F18-STa, F4-LT-STa-STb, F4-STa, F4-LT-STb e F18-STa-STx2e. Beta-hemólise foi observada em 47,4% das amostras e houve associação significativa entre amostras hemolíticas e fatores de virulência F4, F18, STa e STx2e. Quanto consistência fecal, houve associação significativa de fezes líquidas e fímbria F4, toxina STa e virotipos F4-STa e F4-F5-LT-STa-STb. A associação significativa da ETEC e fezes líquidas em leitões de creche, é importante para priorizar a amostragem de fezes com essa consistência para no diagnóstico etiológico da diarreia.


Sujets)
Animaux , Diarrhée/étiologie , Escherichia coli entérotoxigène/isolement et purification , Escherichia coli entérotoxigène/pathogénicité , Facteurs de virulence/analyse , Suidae/microbiologie , Réaction de polymérisation en chaine multiplex/médecine vétérinaire
4.
Rev. bras. plantas med ; 18(1): 105-112, jan.-mar. 2016. tab
Article Dans Portugais | LILACS | ID: lil-780044

Résumé

RESUMO Este trabalho teve por objetivo avaliar o efeito bactericida in vitro de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica (ETEC). Dentre os óleos essenciais estudados, três foram extraídos in situ por arraste a vapor e treze foram adquiridos comercialmente. Todos os óleos foram analisados por CG-EM e CG-DIC. A atividade bactericida foi avaliada pelo método de microdiluição utilizando-se caldo triptona de soja e microplacas de poliestireno de 96 poços, com posterior plaqueamento das culturas em ágar triptona de soja. Os óleos essenciais de Cinnamomum cassia e de Thymus vulgaris apresentaram concentração mínima bactericida (CMB) de 0,12% e 0,25%, respectivamente. Já os óleos comerciais de Syzygium aromaticum e Origanum vulgare apresentaram ambos CMB de 0,50% e os óleos extraídos in situ de Cymbopogon citratus e Origanum vulgare apresentaram ambos CMB de 1,00%. Os dezesseis óleos essenciais apresentaram composição química qualitativa e quantitativa distintas. As análises químicas dos óleos essenciais de Cinnamomum cassia e de Thymus vulgaris tiveram a presença majoritária de E-cinamaldeído (84,52%) e timol (50,89%). Conclui-se que os óleos de C. cassia e T. vulgaris foram os mais eficazes na inibição do crescimento in vitro dessa bactéria, a qual possui diferentes níveis de sensibilidade dependendo da composição química do óleo.


ABSTRACT This study aimed to evaluate the bactericidal effect in vitro of sixteen essential oils on enterotoxigenic Escherichia coli (ETEC). Among the essential oils, three were extracted in situ by steam distillation and thirteen were purchased commercially. All oils were analyzed by GC-MS and GC-FID. The bactericidal activity was evaluated by the microdilution method using tryptone soy broth, and 96-well polystyrene microplates with subsequent plating of the cultures in tryptone soy agar. Cinnamomum cassia and Thymus vulgaris essential oils showed minimal bactericidal concentration (MBC) 0.12% and 0.25%, respectively. Both commercial oils of Syzygium aromaticum and Origanum vulgare showed MBC of 0.50% and the oils extracted in situ Origanum vulgare and Cymbopogon citratus showed both MBC of 1.00%. The sixteen essential oils pointed out distinct qualitative and quantitative chemical composition. Chemical analysis of Cinnamomum cassia and Thymus vulgaris oils had the predominant presence of E-cinnamaldehyde (84.52% ± 0.07%) and thymol (50.89% ± 0.31%). In conclusion, T. vulgaris and C. cassia oils were the most effective in inhibiting in vitro growth of this bacterium, which has different sensitivity levels depending on the chemical composition of the oil.


Sujets)
Huile essentielle/analyse , Chimie , Escherichia coli entérotoxigène/classification , Chromatographie en phase gazeuse/méthodes , Cinnamomum zeylanicum , Thymus (plante)/classification
5.
Journal of Bacteriology and Virology ; : 37-44, 2013.
Article Dans Coréen | WPRIM | ID: wpr-87593

Résumé

Of total 1,438 specimens of patients with diarrhea in Seoul, 2011, 217 samples (15%) were found pathogenic Escherichia coli that included 192 strains (89%) of enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). The highest isolation rate for ETEC and EAEC was found in August and September. Sixty two pathogenic E. coli strains (34 ETEC and 28 EAEC strains) were selected from 175 strains (94 ETEC and 81 EAEC strains) isolated in August and September. Of 94 strains characterized for ETEC phenotype, 76 (81%) expressed heat-stable toxin (ST) only. Antimicrobial susceptibility test was carried out by using sixteen types of antibiotics. A high level of antimicrobial resistance to tetracycline (57%), ampicillin and ticarcillin (54%) was observed among EAEC isolates while the highest resistance rate of ETEC was found for nalidixic acid (47%), followed by tetracycline (32%). As to the antimicrobial susceptibility test, EAEC showed the complicated multi-drug resistant patterns in which the resistance was higher than ETEC. Pulsed-field gel electrophoresis (PFGE) was carried out to examine the genetic relatedness among ETEC and EAEC isolates. Except for 11 strains, 51 strains were divided by eight pulsotypes. In PFGE analysis, isolates from foodborne disease outbreaks in August and September 2011 showed close relation.


Sujets)
Humains , Ampicilline , Antibactériens , Diarrhée , Épidémies de maladies , Électrophorèse en champ pulsé , Escherichia coli entérotoxigène , Escherichia coli , Maladies d'origine alimentaire , Acide nalidixique , Phénotype , Tétracycline , Ticarcilline
6.
Braz. j. microbiol ; 43(3): 969-980, July-Sept. 2012. graf, tab
Article Dans Anglais | LILACS | ID: lil-656661

Résumé

Enterotoxigenic Escherichia coli (ETEC) strains are leading causes of childhood diarrhea in developing countries. Adhesion is the first step in pathogenesis of ETEC infections and ETEC pili designated colonization factor antigens (CFAs) are believed to be important in the biofim formation, colonization and host cell adhesions. As a first step, we have determined the biofilm capability of ETEC expressing various types of pili (CFA/I, CfaE-R181A mutant/ CfaE tip mutant, CFA/II and CS2). Further, enzyme-linked immunosorbent assay (ELISA) assay were developed to compare the binding specificity of CFA/I, CFA/II (CS1 - CS3) and CS2 of ETEC, using extracted pili and piliated bacteria. CFA/II strain (E24377a) as well as extracted pili exhibited significantly higher binding both in biofilm and ELISA assays compared to non piliated wild type E24377a, CFA/I and CS2 strains. This indicates that co-expression of two or more CS2 in same strain is more efficient in increasing adherence. Significant decrease in binding specificity of DH5αF'lacIq/∆cotD (CS2) strain and MC4100/pEU2124 (CfaE-R181A) mutant strain indicated the important contribution of tip proteins in adherence assays. However, CS2 tip mutant strain (DH5αF'lacIq/pEU5881) showed that this specific residue may not be important as adhesions in these strains. In summary, our data suggest that pili, their minor subunits are important for biofilm formation and adherence mechanisms. Overall, the functional reactivity of strains co expressing various antigens, particularly minor subunit antigen observed in this study suggest that fewer antibodies may be required to elicit immunity to ETEC expressing a wider array of related pili.


Sujets)
Enfant , Adhésines bactériennes , Diarrhée du nourrisson , Infections à Escherichia coli , Escherichia coli entérotoxigène/enzymologie , Escherichia coli entérotoxigène/isolement et purification , Techniques immunoenzymatiques , Méthodes , Sensibilité et spécificité , Virulence
7.
Article Dans Anglais | IMSEAR | ID: sea-163770

Résumé

Escherichia coli isolates from different samples of droppings collected from the different farms of broiler and local poultry were characterized to confirm the virulence. E. coli isolates recovered from different farms were examined for presence of genes encoding patho groups such as shiga like toxin producing Escherichia coli (STEC), (stx1/stx2) by Duplex PCR and then analysed the PCR Amplicons by AGE. The three and four isolates of E. coli recovered from local and boiler poultry were STEC because of presence of the stx1 and stx2 genes. Presence of stx1 and stx2 genes clearly indicated these as prime cause of pathogenecity. Further, demonstration of STEC in poultry becomes a public health concern, as poultry are potential reservoir of such agents, which may cause extra intestinal diseases like haemolytic uremic syndrome and thrombocytopenic purpurea by stx1 &2 and these toxins kill vascular endothelial cells.

8.
Rev. argent. microbiol ; 44(2): 85-88, jun. 2012. tab
Article Dans Espagnol | LILACS | ID: lil-657616

Résumé

El objetivo del trabajo fue caracterizar mediante PCR 47 aislamientos de Escheríchia coli recuperados de 32 cerdos con diagnóstico clínico de diarrea posdestete (DPD) y de 3 cerdos con enfermedad de los edemas (ED). Sobre 44 aislamientos provenientes de cerdos con DPD, 42 (95,5 %) fueron caracterizados como E. coli enterotoxigénicos (ETEC) y 2 (4,5 %) como E. coli productores de toxina Shiga (STEC). Catorce aislamientos de ETEC (33,3 %) fueron positivos para los genes estl/estlI/fedA. El genotipo más complejo fue eltA/estll/east1/faeG/aidA. Los aislamientos provenientes de cerdos con ED se clasificaron como STEC porcinos y fueron portadores de stxJaidA. Once aislamientos (25 %) fueron portadores del gen que codifica la expresión de la adhesina AIDA-I. Sin embargo, en ningún aislamiento se detectaron los genes que codifican la expresión de las adhesinas F5, F6, F41, de intimina y de "Paa". La prevención de la DPD y de la ED podría realizarse mediante el desarrollo de vacunas que generen anticuerpos contra las adhesinas de las cepas de E. coli prevalentes en la Argentina.


The purpose of this work was to characterize 47 Escherichia coli strains isolated from 32 pigs diagnosed with postweaning diarrhea and tree pigs with edema disease by PCR. Forty two (95.5 %) of the strains isolated from diarrheic pigs were characterized as enterotoxigenic E. coli (ETEC) and 2 (4.5 %) as Shiga toxin-producing E. coli (STEC). Fourteen (33.3 %) ETEC strains were positive for est/estll/fedA genes. The most complex genotype was eltA/estl/faeG/aidA. Strains isolated from pigs with ED were classified as porcine STEC and were stxjaidA carriers. Eleven (25 %) strains carried the gene encoding adhesln protein AIDA-I. However, genes coding for F5, F6, F41, intimin and Paa were not detected. The development of vaccines generating antibodies against prevalent E. coli adhesins in Argentina could be useful for the prevention of PWD and ED.


Sujets)
Animaux , Diarrhée/médecine vétérinaire , Maladie de l'oedème/microbiologie , Escherichia coli entérotoxigène/génétique , Infections à Escherichia coli/médecine vétérinaire , Protéines Escherichia coli/génétique , Gènes bactériens , Escherichia coli producteur de Shiga-toxine/génétique , Maladies des porcs/microbiologie , Adhésines d'Escherichia coli/génétique , Argentine/épidémiologie , Épidémies de maladies , Diarrhée/épidémiologie , Diarrhée/microbiologie , Maladie de l'oedème/épidémiologie , Escherichia coli entérotoxigène/isolement et purification , Entérotoxines/génétique , Infections à Escherichia coli/épidémiologie , Infections à Escherichia coli/microbiologie , Génotype , Sus scrofa , Suidae , Escherichia coli producteur de Shiga-toxine/isolement et purification , Maladies des porcs/épidémiologie , Sevrage
9.
Article Dans Anglais | IMSEAR | ID: sea-135747

Résumé

Background & objectives: Diverse mechanisms have been identified in enteric bacteria for their adaptation and survival against multiple classes of antimicrobial agents. Resistance of bacteria to the most effective fluoroquinolones have increasingly been reported in many countries. We have identified that most of the enterotoxigenic Escherichia coli (ETEC) were resistant to several antimicrobials in a diarrhoea outbreak at Ahmedabad during 2000. The present study was done to identify several genes responsible for antimicrobial resistance and mobile genetic elements in the ETEC strains. Methods: Seventeen ETEC strains isolated from diarrhoeal patients were included in this study. The antimicrobial resistance was confirmed by conventional disc diffusion method. PCR and DNA sequencing were performed for the identification of mutation in the quinolone resistance-determining regions (QRDRs). Efflux pump was tested by inhibiting the proton-motive force. DNA hybridization assay was made for the detection of integrase genes and the resistance gene cassettes were identified by direct sequencing of the PCR amplicons. Results: Majority of the ETEC had GyrA mutations at codons 83 and 87 and in ParC at codon 80. Six strains had an additional mutation in ParC at codon 108 and two had at position 84. Plasmid-borne qnr gene alleles that encode quinolone resistance were not detected but the newly described aac(6’)-Ib-cr gene encoding a fluoroquinolne-modifying enzyme was detected in 64.7 per cent of the ETEC. Class 1 (intI1) and class 2 (intI2) integrons were detected in six (35.3%) and three (17.6%) strains, respectively. Four strains (23.5%) had both the classes of integrons. Sequence analysis revealed presence of dfrA17, aadA1, aadA5 in class 1, and dfrA1, sat1, aadA1 in class 2 integrons. In addition, the other resistance genes such as tet gene alleles (94.1%), catAI (70.6%), strA (58.8%), blaTEM-1(35.2%), and aphA1-Ia (29.4%) were detected in most of the strains. Interpretation & conclusions: Innate gene mutations and acquisition of multidrug resistance genes through mobile genetic elements might have contributed to the emergence of multidrug resistance (MDR) in ETEC. This study reinforces the necessity of utilizing molecular techniques in the epidemiological studies to understand the nature of resistance responsible for antimicrobial resistance in different species of pathogenic bacteria.


Sujets)
Antibactériens/pharmacologie , DNA gyrase/effets des médicaments et des substances chimiques , DNA gyrase/génétique , DNA topoisomerase IV/effets des médicaments et des substances chimiques , DNA topoisomerase IV/génétique , ADN bactérien/analyse , ADN bactérien/génétique , Diarrhée/traitement médicamenteux , Diarrhée/épidémiologie , Diarrhée/microbiologie , Épidémies de maladies , Multirésistance bactérienne aux médicaments/effets des médicaments et des substances chimiques , Multirésistance bactérienne aux médicaments/génétique , Escherichia coli entérotoxigène/génétique , Escherichia coli entérotoxigène/isolement et purification , Escherichia coli entérotoxigène/pathogénicité , Escherichia coli/classification , Escherichia coli/effets des médicaments et des substances chimiques , Escherichia coli/génétique , Escherichia coli/isolement et purification , Infections à Escherichia coli/traitement médicamenteux , Infections à Escherichia coli/épidémiologie , Infections à Escherichia coli/génétique , Infections à Escherichia coli/microbiologie , Fluoroquinolones/pharmacologie , Gènes MDR/génétique , Humains , Inde/épidémiologie , Intégrons/génétique , Tests de sensibilité microbienne , Mutation/effets des médicaments et des substances chimiques , Mutation/génétique , Quinolinone/pharmacologie
10.
Article Dans Anglais | IMSEAR | ID: sea-135370

Résumé

It was shown earlier that immune responses against cholera toxin (CT) as well as Vibrio cholerae lipopolysaccharide (LPS) or whole bacterial cells (WC) were protective and that these different antibody specificities co-operated synergistically for protection against experimental cholera. Similarly, antibodies against the heat-labile toxin (LT) and major colonization factors (CFs) of enterotoxingenic Escherichia coli (ETEC) co-operated synergistically for protection against LT-producing ETEC expressing homologous CFs. Studies in humans revealed that repeated oral antigen administration was optimal in inducing intestinal immune responses. Based on these findings oral inactivated vaccines consisting of toxin antigen and whole cells, i.e. the licensed recombinant cholera B subunit (rCTB)-WC cholera vaccine Dukoral®, and candidate ETEC vaccines have been developed. In different trials the rCTB-WC cholera vaccine has provided very high (85-100%) short term protection, which was significantly higher than that induced by the WC component alone, whereas rCTB-WC and WC alone provided comparable (50-60%), long term protection. An oral ETEC vaccine consisting of rCTB and formalin-inactivated E. coli bacteria expressing major CFs was shown to be safe and immunogenic in adults and children in different countries. The vaccine also induced significant protection against non-mild ETEC diarrhoea, i.e. diarrhoea interfering with daily activity in American travellers but not against ETEC diarrhoea in young children in Egypt. Against this background, a modified ETEC vaccine consisting of recombinant E. coli strains overexpressing the major CFs and a more LT like hybrid toxoid (LCTBA) has been developed. This vaccine will be tested soon alone and together with a mucosal adjuvant, i.e. dmLT, in clinical trials.


Sujets)
Animaux , Choléra/prévention et contrôle , Vaccins anticholériques/immunologie , Escherichia coli entérotoxigène/pathogénicité , Infections à Escherichia coli/microbiologie , Infections à Escherichia coli/prévention et contrôle , Vaccins anti-Escherichia coli/immunologie , Humains , Vibrio cholerae/pathogénicité , Facteurs de virulence/immunologie
11.
Korean Journal of Clinical Microbiology ; : 186-192, 2009.
Article Dans Coréen | WPRIM | ID: wpr-209053

Résumé

BACKGROUND: The incidence of infectious diarrheal disease in Korea has decreased over the past decade, but traveler's diarrhea (TD) is increasing in frequency. We therefore investigated the distribution of the causative agents of TD. METHODS: A total of 132 rectal swab specimens were acquired from TD patients who entered the country via Gimhae International Airport. The specimens were screened for 12 bacterial pathogens by real-time PCR, and target pathogens were isolated from the PCR positive specimens using conventional microbiological isolation methods. RESULTS: A total of 93 specimens (70.5%) showed positive PCR screening results, and of these specimens, nine species and 50 isolates (37.9%), including Vibrio parahaemolyticus (18 isolates) and ETEC (17 isolates), were isolated. No specimens were PCR positive for Listeria monocytogenes or Campylobacter jejuni, and no pathogenic Bacillus cereus were isolated. CONCLUSION: Even though viruses and EAEC were not included as target pathogens, the high isolation rate of these pathogens in this study provides indirect evidence that most cases of pathogen-negative TD are caused by undetected bacterial agents. Furthermore, our study results confirm the effectiveness of real-time PCR-based screening methods. This study is the first report in Korea to demonstrate that ETEC and V. parahaemolyticus are the major causative pathogens of TD, and this knowledge can be used to help treat and prevent TD.


Sujets)
Humains , Aéroports , Bacillus cereus , Campylobacter jejuni , Diarrhée , Dysenterie , Escherichia coli entérotoxigène , Incidence , Corée , Listeria monocytogenes , Dépistage de masse , Réaction de polymérisation en chaîne , Réaction de polymérisation en chaine en temps réel , Vibrio parahaemolyticus
12.
Journal of Chongqing Medical University ; (12)2007.
Article Dans Chinois | WPRIM | ID: wpr-578439

Résumé

Objective:To clone and express colonization factor antigen Ⅰ(CFA/Ⅰ) of enterotoxigenic Escherichia coli (ETEC) in E.coli DH5?. Methods:CFA/Ⅰ gene was cloned by PCR from H10407 and recombined to a expression vector pBV220.This vector was designated pBV220- CFA/Ⅰand transformed into E.coli DH5?. The product was tested by SDS-PAGE and immunogenesis test. Results:The CFA/Ⅰ gene could be expressed in E.coli and contained strong immunogenesis by immune test. Conclusion:This study paved the way for using ETEC CFA/Ⅰ recombinant as a vaccine candidate in future.

13.
Infection and Chemotherapy ; : 30-38, 2006.
Article Dans Anglais | WPRIM | ID: wpr-722140

Résumé

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) has been well known pathogen as a cause of travelers' diarrhea. Nowadays, however, ETEC is also increasingly recognized as the cause of foodborne or waterborne outbreaks. We investigated an outbreak of a high school in Gwangju metropolitan city to trace the source of infection and the mode of transmission of ETEC. MATERIALS AND METHODS: All symptomatic persons were interviewed and filled out the questionnaires. We surveyed their clinical symptoms and the foods that they ate. We checked the facilities of the school, dinning room and water supply system. Microbiologic examination were carried out on above symptomatic persons and many environmental specimens. All gathered samples were examined in Gwangju city Health & Environment Research Institute. ETEC isolates were submitted to Korea Center for Disease Control and Prevention (KCDC) for Pulsed-field gel electrophoresis (PFGE). We also requested water quality analysis of water samples to Waterworks Research Institute. RESULTS: The 39 students and one sibling who visited and ate school meal showed symptoms. All staffs and cooks showed no symptom. Among 51 stool specimens, ETEC was isolated from 19 (18: students, 1:cook). ETEC was also isolated from specimens from a purifier and a water tap of the dinning room and water tank (underground water). In PFGE test, isolates from 18 persons showed identical pattern, but the PFGE patterns from water were different. Isolates of water samples showed different PFGE patterns even within the same sample. Investigation of the water distribution system revealed that contaminated underground water had been supplied to the dinning room and students of the school were exposed to it. CONCLUSION: This is the outbreak of ETEC infection occurred in a high school. Besides students, ETEC was also isolated from water samples. Considering some epidemiologic features, we suspect the mode of transmission may be waterborne despite the inconsistent PFGE results.


Sujets)
Humains , Académies et instituts , Diarrhée , Épidémies de maladies , Électrophorèse en champ pulsé , Escherichia coli entérotoxigène , Nappe phréatique , Corée , Repas , Fratrie , Eau , Qualité de l'eau , Alimentation en eau , Enquêtes et questionnaires
14.
Infection and Chemotherapy ; : 30-38, 2006.
Article Dans Anglais | WPRIM | ID: wpr-721635

Résumé

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) has been well known pathogen as a cause of travelers' diarrhea. Nowadays, however, ETEC is also increasingly recognized as the cause of foodborne or waterborne outbreaks. We investigated an outbreak of a high school in Gwangju metropolitan city to trace the source of infection and the mode of transmission of ETEC. MATERIALS AND METHODS: All symptomatic persons were interviewed and filled out the questionnaires. We surveyed their clinical symptoms and the foods that they ate. We checked the facilities of the school, dinning room and water supply system. Microbiologic examination were carried out on above symptomatic persons and many environmental specimens. All gathered samples were examined in Gwangju city Health & Environment Research Institute. ETEC isolates were submitted to Korea Center for Disease Control and Prevention (KCDC) for Pulsed-field gel electrophoresis (PFGE). We also requested water quality analysis of water samples to Waterworks Research Institute. RESULTS: The 39 students and one sibling who visited and ate school meal showed symptoms. All staffs and cooks showed no symptom. Among 51 stool specimens, ETEC was isolated from 19 (18: students, 1:cook). ETEC was also isolated from specimens from a purifier and a water tap of the dinning room and water tank (underground water). In PFGE test, isolates from 18 persons showed identical pattern, but the PFGE patterns from water were different. Isolates of water samples showed different PFGE patterns even within the same sample. Investigation of the water distribution system revealed that contaminated underground water had been supplied to the dinning room and students of the school were exposed to it. CONCLUSION: This is the outbreak of ETEC infection occurred in a high school. Besides students, ETEC was also isolated from water samples. Considering some epidemiologic features, we suspect the mode of transmission may be waterborne despite the inconsistent PFGE results.


Sujets)
Humains , Académies et instituts , Diarrhée , Épidémies de maladies , Électrophorèse en champ pulsé , Escherichia coli entérotoxigène , Nappe phréatique , Corée , Repas , Fratrie , Eau , Qualité de l'eau , Alimentation en eau , Enquêtes et questionnaires
15.
Ciênc. rural ; 26(2): 247-250, maio-ago. 1996. tab
Article Dans Anglais | LILACS | ID: lil-622998

Résumé

Prevalence of Escherichia coli in foods of animal origin from the city of Pelotas, Brazil, was determined. The ocurrence of enterotoxigenic (ETEC) and classic enteropathogenic (EPEC) serogroups among E. coli isolates was determined. E. coli was isolated from 68% of the food samples surveyed. Of 36 food samples tested, 11(30%) and 24(66%) were positive for EPEC and ETEC strains respectively. However, of 187 E. coli isolates tested, 30(16%) were EPEC compared to 75(40%) which were ETEC. The antibiotic resistance pattern revealed that the isolates were highly sensitive to all antibiotics tested.


Foi determinada a prevalência de Escherichia coli em alimentos de origem animal na cidade de Pelotas, RS. Determinou-se a ocorrência de cepas enterotoxigênicas (ETEC) e enteropatogênicas clássicas (EPEC) entre os isolamentos de E. coli. Em 86% das amostras de alimentos analisadas foi detectada a presença de E. coli. De 36 amostras de alimentos testadas, 11(30%) e 24(66%) foram positivas para EPEC e ETEC, respectivamente. Entre os 187 isolamentos de E. coli testados. 30(16%) pertenciam a sorogrupos de EPEC e 75(40%) foram positivos para ETEC. O perfil de resistência à antibióticos revelou que os isolados foram altamente sensíveis a todos os antibióticos testados.

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