RESUMO
Escherichia coli strains are part of the normal biota of humans and animals; however, several clinical reports have implicated E. coli as the etiological agent of diarrhea in humans and companion animals. Thus, the aim of the present study was to know if companion dogs in the city of San Luis Potosi are colonized with virulent potentially harmful E. coli strains. Rectal swabs from 30 dogs, 13 with and 17 without diarrhea were analyzed. Phylogenetic and virulence genes analysis was performed to the E. coli isolates. Additionally, the Kirby-Bauer test was used to analyze the sensitivity to 32 different antimicrobials from 14 families. Eighty-five isolates were identified as E. coli and detected in 97% of healthy and diarrheic dog samples. E. coli isolates from healthy dogs carried several virulence genes, in contrast with those from diarrheic animals that presented only eaeA. In healthy dogs, phylogenetic analysis showed that 57% and 43% of E. coli isolates belonged to commensal (A and B1) and virulent (B2 and D) groups respectively. Meanwhile, diarrheic dogs showed that 69% of the isolates were identified as virulent B2 and D phylogroups. Moreover, E. coli resistant to ß-lactams, aminoglycosides, tetracycline, quinolones, and folate inhibitors were detected in both groups of dogs. The presence of E. coli with eaeA virulence gene in diarrheic dogs, suggest that these strains are associated with the animal´s condition. Finally, major attention must be drawn to the careful handling of dogs because of their capability to harbor and disseminate virulent E. coli strains.
Assuntos
Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/transmissão , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Animais de Estimação/microbiologia , Animais , Antibacterianos/farmacologia , Diarreia/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Cães , Escherichia coli/classificação , Humanos , Filogenia , Virulência/genética , Fatores de Virulência/genéticaRESUMO
Lactobacilli have been shown to promote health functions. In this study, we analyzed the mechanism by which four different strains of probiotics affected innate immunity, such as regulation of ROS, cytokines, phagocytosis, bactericidal activity, signaling by NF-κB pp65, and TLR2 activation. The production of ROS was dependent on the concentration and species of Lactobacillus. The results obtained from the tested strains (Lactobacillus rhamnosus GG, L. rhamnosus KLSD, L. helveticus IMAU70129, and L. casei IMAU60214) showed that strains induced early proinflammatory cytokines such as IL-8,TNF-α, IL-12p70, and IL-6. However, IL-1ß expression was induced only by L. helveticus and L. casei strains (after 24 h stimulation). Phagocytosis and bactericidal activity of macrophages against various pathogens, such as S. aureus, S. typhimurium, and E. coli, were increased by pretreatment with Lactobacillus. The nuclear translocation NF-κB pp65 and TLR2-dependent signaling were also increased by treatment with the probiotics. Taken together, the experiments demonstrate that probiotic strains of Lactobacillus exert early immunostimulatory effects that may be directly linked to the initial inflammation of the response of human macrophages.
Assuntos
Imunidade Inata , Inflamação , Lactobacillus/imunologia , Ativação de Macrófagos , Probióticos , Células Cultivadas , Citocinas/biossíntese , Citocinas/imunologia , Humanos , Interleucina-12/biossíntese , Interleucina-6/biossíntese , Interleucina-8/biossíntese , Lactobacillus/fisiologia , Lacticaseibacillus rhamnosus/imunologia , Lacticaseibacillus rhamnosus/fisiologia , NF-kappa B/metabolismo , Fagocitose , Transdução de Sinais , Fator de Necrose Tumoral alfa/biossínteseRESUMO
El presente artículo busca analizar cómo los médicos bogotanos entendieron la gripa como entidad patológica a comienzos del siglo XX. Para ello se examinan algunos de los recursos cognitivos que los galenos utilizaron para abordar y atender la epidemia de 1918 en la ciudad de Bogotá. En este abordaje, se puede vislumbrar cómo la epidemia de gripa se tornó en un fenómeno social de enorme complejidad y cómo su definición médica se forjó en un campo de debate enmarcado por los grandes cambios paradigmáticos que vivió la medicina de finales del siglo XIX.El texto explora algunos de los conceptos centrales que sirvieron de sustento para la comprensión etiopatológica de la gripa, presenta una descripción del saber clínico que se tenía acerca de la enfermedad y se detiene, de manera especial, en el debate que suscitó la identificación de un microorganismo específico como agente causal de la gripa.
Assuntos
Humanos , Surtos de Doenças , MedicinaRESUMO
Colombia tiene una escasa experiencia en identificar prioridades de investigación en salud. En el año 2004 se inició un proyecto para identificar prioridades de investigación en salud, entendiendo por tales las que resultan de un ejercicio ordenado de ponderación basado en una valoración juiciosa de problemáticas sanitarias cuya respuesta y/o solución puede lograrse en gran parte por medio de conocimientos y procesos de investigación. Como referentes del proyecto se tuvieron en cuenta algunos de los métodos de priorización utilizados y recomendados en el ámbito internacional, entre ellos la matriz combinada del Global Forum for Health Resarch. Se pusieron en práctica dos trayectos metodológicos principales: por una parte, diseño y aplicación de un método para ponderar u ordenar, de manera cualitativa y cuantitativa, las problemáticas de investigación en salud; por otra parte, construcción de consensos con investigadores y representantes de comunidades científicas. Para identificar las problemáticas de salud predominantes se realizaron dos reuniones nacionales, dos reuniones regionales y un foro virtual. Una vez identificadas las problemáticas de salud predominantes, con su respectiva estimación de carga de enfermedad, estas se valoraron por políticos y decisores y se calificaron por investigadores de ciencias básicas, ciencias clínicas y salud pública, en términos del aporte del conocimiento requerido para afrontar, controlar o resolver tales problemáticas. Se obtuvieron unas prioridades de investigación en salud por áreas globales: enfermedades crónicas, enfermedades infecciosas emergentes, Tuberculosis/Lepra, infección nosocomial e infecciones de transmisión sexual/VIH/SIDA.
Colombia lacks experience in identifying health research priorities. A project for idenifying health research priorities was begun in 2004 (meaning those arising from weighting and ordering health and disease problems which could be mainly resolved by research and knowledge). The Global Forum for Health Research combined matrix method, and other methods, was used as reference for developing projects and putting two main methodological paths into practice: designing and applying a method for qualitatively and quantitatively weighting and ordering health research problems and building consensus with researchers and scientific community representatives. Two national meetings, two regional meetings and a virtual forum were held for identifying predominant health problems. Once the predominant health problems had been identified (with the respective estimation of disease load), then they were evaluated by politicians and decision-makers and rated by basic science, clinical science and public health researchers in terms of making a contribution towards knowledge for facing, controlling or resolving such problems. Some health research priorities were obtained (by areas and others being overall priorities): chronic diseases, emergent infectious diseases, tuberculosis/leprosy, nosocomial infection and sexually transmitted diseases/HIV/AIDS.
Assuntos
Pesquisa sobre Serviços de Saúde , Pesquisa , ColômbiaRESUMO
Muestra la ruta de lectura que acompanã a los españoles en su llegada al Nuevo Continente. Contene los antecedentes de la medicina que se conocía y praticaba en Europa. Conta etapas históricas hasta llegar a la actualidad. Desde la medicina, hay en este tratado una visión del hombre, de la sociedad y de la cultura en un recorrido por más de cinco centurias.
Assuntos
História da Medicina , Médicos/história , ColômbiaRESUMO
Muestra la ruta de lectura que acompanã a los españoles en su llegada al Nuevo Continente. Contene los antecedentes de la medicina que se conocía y praticaba en Europa. Conta etapas históricas hasta llegar a la actualidad. Desde la medicina, hay en este tratado una visión del hombre, de la sociedad y de la cultura en un recorrido por más de cinco centurias(AU)
Assuntos
História da Medicina , Médicos/história , ColômbiaRESUMO
Enteroaggregative Escherichia coli (EAEC) is an emergent bacterial pathogen. The first studies in developing countries with EAEC strains, showed that this bacterium was associated with persistent diarrhea. However, new studies showed that EAEC may be associated also with acute diarrhea, with both nosocomial and community outbreaks worldwide, and as an important pathogen of diarrheal disease in human immunodeficiency virus-infected adults. EAEC strains are recognized by their characteristic aggregative adherence or "stacked-brick" pattern to epithelial cells. Although the pathogenesis of EAEC infection is not well understood, cellular changes observed in animal models and in vitro assays, suggested that the alterations in the intestinal mucosa during EAEC infection are associated with adherence factors and toxins production. The damage has been associated with the release of inflammatory mediators, which may contribute also to the intestinal illness. The dissemination of the high pathogenicity island from Yersinia pestis evolutionary group to EAEC has been show; different studies suggest that it may contribute to the virulence of EAEC strains. Molecular methods to investigate the presence of plasmid and chromosomal EAEC-associated virulence markers, have been used for the characterization and epidemiological studies of EAEC strains. Although the clinical and epidemiological importance of EAEC have been demonstrated in different studies, Escherichia coli strains with adherent agreggative phenotype are commonly isolated from healthy children and environmental sources. This support the necessity to study virulence factors no related with the cells adherence pattern, that show the specific EAEC pathogenic clones associated whit intestinal disease.
Assuntos
Doenças Transmissíveis Emergentes/microbiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Adulto , Animais , Aderência Bacteriana , Proteínas de Bactérias/fisiologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Células Cultivadas/microbiologia , Criança , Doenças Transmissíveis Emergentes/epidemiologia , Diarreia/microbiologia , Surtos de Doenças , Células Epiteliais/microbiologia , Escherichia coli/classificação , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Genes Bacterianos , Ilhas Genômicas/genética , Vida Livre de Germes , Saúde Global , Humanos , Mucosa Intestinal/microbiologia , Técnicas de Cultura de Órgãos , Plasmídeos/genética , Sus scrofa/microbiologia , Virulência , Yersinia pestis/genéticaRESUMO
Escherichia coli O157:H7 is a foodborne pathogenic bacterium that can reside undetected in the gastrointestinal tract of cattle because colonization by this bacterium is asymptomatic. Recent research has indicated that swine can carry and transmit this pathogen as well. The development of more advanced and sensitive detection techniques has improved the limit of detection and increased sensitivity for this important pathogen. This study was undertaken to determine the prevalence of E. coli O157 in cattle and swine in Mexico with the more sensitive detection technique of immunomagnetic bead separation. Samples (n = 60 per farm) were taken from four cattle and four swine farms (n = 240 cattle samples, n = 240 swine samples) located throughout central Mexico in October 2001. The prevalence of E. coli O157 was found to be only 1.25% on cattle farms and 2.1% on swine farms. The prevalence in cattle in this study is lower than that reported in the United States and could be related to the lower reported prevalence of E. coli O157 in humans in Mexico. However, further research is needed to verify prevalence throughout other regions of Mexico, as well as prevalence during other seasons of the year.
Assuntos
Doenças dos Bovinos/epidemiologia , Infecções por Escherichia coli/veterinária , Escherichia coli O157/isolamento & purificação , Doenças dos Suínos/epidemiologia , Animais , Bovinos , Infecções por Escherichia coli/epidemiologia , Feminino , Contaminação de Alimentos/prevenção & controle , Separação Imunomagnética/veterinária , Masculino , México/epidemiologia , Prevalência , SuínosRESUMO
Se examina la forma como se han entendido las acciones de promoción y prevención, estableciendo que si bien estas acciones han adquirido importancia y visibilidad, aun existe confusión frente a la especificidad de cada una de ellas. se elabora una comparación entre las lógicas que guían la promoción de la salud y la prevención de la enfermedad, con el fin de aclarar sus rasgos distintivos y proponer, desde su diferencia, la articulación de las acciones en una política de salud integral. Por último, se reflexiona sobre las dificultades y los obstáculos que existen para asumir la especificidad de la promoción de la salud en el modelo de atención predominante en Colombia.
Assuntos
Sistemas de Saúde , Prevenção Primária , Promoção da Saúde , ColômbiaRESUMO
In this study, the presence and pathogenic characteristics of Escherichia coli strains in pozol, an acid-fermented maize beverage consumed in South-eastern Mexico, were determined. Seventy-three E. coli strains were isolated at early and late times (6 and 48 h) during the pozol fermentation process, when pH values of the doughs were 6.7-4.7 (6 h) and 4.7-3.7 (48 h). Serotypes that belong to diarrheagenic E. coli serogroups O18, O88, O8, O11, O20, O173 were identified. HEp-2 cell adherence in vitro assays showed localized, diffuse and aggregative adherence patterns among some of these strains. A DNA colony hybridization analysis with different probes showed the presence of virulence genes related to diarrheal pathogenesis. Thirty-three percent of the E. coli strains were tetracycline-resistant and 95% had a 20 kb plasmid. The presence and survival of potentially pathogenic E. coli in acid-fermented pozol suggest that such foods may be a potential source of foodborne outbreaks.
Assuntos
Escherichia coli/crescimento & desenvolvimento , Escherichia coli/fisiologia , Zea mays/microbiologia , Aderência Bacteriana/fisiologia , Bebidas/microbiologia , Linhagem Celular , Contagem de Colônia Microbiana , Diarreia/microbiologia , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla , Escherichia coli/genética , Escherichia coli/patogenicidade , Fermentação , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Sorotipagem , VirulênciaRESUMO
Pet toxin is a serine protease from enteroaggregative Escherichia coli which has been described as causing enterotoxic and cytotoxic effects. In this paper we show that Pet produces spectrin and fodrin (nonerythroid spectrin) disruption. Using purified erythrocyte membranes treated with Pet toxin, we observed degradation of alpha- and beta-spectrin chains; this effect was dose and time dependent, and a 120-kDa protein fraction was observed as a breakdown product. Spectrin degradation and production of the 120-kDa subproduct were confirmed using specific antibodies against the alpha- and beta-spectrin chains. The same degradation effect was observed in alpha-fodrin from epithelial HEp-2 cells, both in purified cell membranes and in cultured cells which had been held in suspension for 36 h; these effects were confirmed using antifodrin rabbit antibodies. The spectrin and fodrin degradation caused by Pet is related to the Pet serine protease motif. Fluorescence and light microscopy of HEp-2 Pet-treated cells showed morphological alterations, which were associated with irregular distribution of fodrin in situ. Spectrin and fodrin degradation by Pet toxin were inhibited by anti-Pet antibodies and by phenylmethylsulfonyl fluoride. A site-directed Pet mutant, which had been shown to abolish the enterotoxic and cytotoxic effects of Pet, was unable to degrade spectrin in erythrocyte membranes or purified spectrin or fodrin in epithelial cell assays. This is a new system of cellular damage identified in bacterial toxins which includes the internalization of the protease, induction of some unknown intermediate signaling steps, and finally the fodrin degradation to destroy the cell.
Assuntos
Toxinas Bacterianas/toxicidade , Proteínas de Transporte/metabolismo , Membrana Celular/efeitos dos fármacos , Enterotoxinas/toxicidade , Proteínas de Escherichia coli , Escherichia coli/patogenicidade , Proteínas dos Microfilamentos/metabolismo , Serina Endopeptidases/toxicidade , Sequência de Aminoácidos , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/isolamento & purificação , Linhagem Celular , Enterotoxinas/química , Enterotoxinas/isolamento & purificação , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Membrana Eritrocítica/efeitos dos fármacos , Escherichia coli/enzimologia , Infecções por Escherichia coli/fisiopatologia , Humanos , Dados de Sequência Molecular , Coelhos , Serina Endopeptidases/química , Serina Endopeptidases/isolamento & purificação , Espectrina/metabolismoRESUMO
Se examinan las propuestas de reforma a la Ley 100 de 1993, presentadas en el Foro Regional sobre Seguridad Social en Salud, llevado a cabo en Bogotá a comienzos de 1999. Con base en 53 documentos se describen los tipos de propuestas, las tendencias que subyacen a las mismas y algunas de las confluencias y divergencias que se encuentran entre diversos actores del Sistema de Seguridad Social. Los temas más frecuentes, en los cuales se inscribían las propuestas, fueron los mecanismos de control estatal, el régimen subsidiado, los planes de beneficios, el sistema de información y la participación social. Se presenta un esquema de análisis de los principales problemas que son reconocidos por actores del Sistema de Seguridad Social en Salud, y se remarca la necesidad de escenarios de debate donde se esclarezcan las bases para garantizar el derecho que tenemos a una integra seguridad social.
Assuntos
Previdência Social , Sistemas de Saúde , Reforma dos Serviços de Saúde , Legislação , Política de Saúde , ColômbiaRESUMO
The pathogenic mechanisms of enteroaggregative Escherichia coli (EAggEC) infection are not fully elucidated. In this work we show that an ammonium sulfate precipitate of culture supernatant of EAggEC strain 049766 increased the potential difference (PD) and the short-circuit current (Isc) in rat jejunal preparations mounted in Ussing chambers. The precipitate contained two major proteins of 108 and 116 kDa, which were partially copurified by chromatography in DEAE-cellulose. This chromatographic fraction (peak I) increased jejunal PD and Isc in a dose-dependent manner, accompanied by a decrease in tissue electrical resistance. These effects were inhibited by incubation of peak I at 75 degreesC for 15 min or for 1 h with proteinase K at 37 degreesC. Rabbit polyclonal antibodies against peak I containing both the 108- and 116-kDa proteins inhibited the enterotoxic effect. Specific polyclonal antibodies raised against the 108-kDa but not against the 116-kDa protein inhibited the enterotoxic effect, suggesting that the 108-kDa protein is the active toxic species. Moreover, another EAggEC strain (065126) producing the 116-kDa protein but not the 108-kDa protein had no effect on rat jejunal mucosa in the Ussing chamber. The >100-kDa fraction derived from prototype EAggEC strain 042, which also expressed both 108- and 116-kDa proteins, also produced an enterotoxic effect on rat jejunal preparations in Ussing chambers; however, the same strain cured of its 65-MDa adherence plasmid did not. A subclone derived from the 65-MDa plasmid expressing the 108-kDa toxin (and not the 116-kDa protein) elicited rises in Isc. Tissue exposed to any preparation containing the 108-kDa toxin exhibited similar histopathologic changes, characterized by increased mucus release, exfoliation of cells, and development of crypt abscesses. Our data suggest that some EAggEC strains produce a ca. 108-kDa enterotoxin/cytotoxin which is encoded on the large virulence plasmid.