Pet dogs potential transmitters of pathogenic Escherichia coli with resistance to antimicrobials.

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.

Probiotic Lactobacillus Strains Stimulate the Inflammatory Response and Activate Human Macrophages.

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.

Pet serine protease from enteroaggregative Escherichia coli stimulates the inflammatory response activating human macrophages.

BACKGROUND: Pet is a toxin from the family of Serine Protease Autotransporters of Enterobacteriaceae which was initially identified in Enteroaggregative Escherichia coli strains. This protease exhibits enterotoxin properties, damages the cell cytoskeleton and induces intestinal epithelium alterations, which are associated with a severe inflammatory process. An in-vitro study was conducted to evaluate the effect of Pet on the migration of human peripheral blood monocytes-derived macrophages and its participation in the activation of the early inflammatory response and cytokine expression. RESULTS: In the macrophage migration activation assay, Pet produced a similar effect to that induced by opsonized zymosan (ZAS). Regarding the cytokine expression, an increase of IL-8, TNF-α (pro-inflammatory) and IL-10 (anti-inflammatory) was identified. In addition to the above results, the nuclear translocation of NF-kB pp65 was also identified. These events are probably related to the inflammatory response identified in the histological examination of intestine rat samples inoculated with Pet during a ligated loop assay. CONCLUSION: The results showed that Pet participates as an immunostimulant molecule for macrophages, which activates both their mobility and cytokine expression. These observations suggest that the toxin participates in the inflammatory process that is observed during the host infection by EAEC Pet producing.

Las ideas médicas sobre la epidemia de gripa de 1918 en Bogotá / Medical ideas in the 1918 flu epidemic

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.

Prioridades de investigación en salud en Colombia: perspectiva de los investigadores / Health research priorities in Colombia from the researchers' point of view

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.

Historia de la medicina en Colombia / Historia de la medicina en Colombia / History of medicine in Colombia

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.

Historia de la medicina en Colombia / Historia de la medicina en Colombia / History of medicine in Colombia

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)

Phenotypic characterization of ipaH+ Escherichia coli strains associated with yolk sac infection.

Seventy-six Escherichia coli serotypes possessing the ipaH gene typical of enteroinvasive E. coli (EIEC) strains were characterized. Biochemical identification of our strains shows positive reactions for lactose fermentation (100% of strains), lysine decarboxylase (98.7% of strains) and motility (67.1% of strains), properties that do not correspond with those described to the EIEC group. The serotypes agree with an initial classification. In this, some common O antigens identified among ipaH+ strains were O2 (n=20), OR (n=11) and non-determined O? (n=10). The O2:NM serotype was the most common. Sixty-six percent (n=50) of the ipaH+ E. coli strains were colicin producers, of them, 26 (34%) produced Col V and other colicins, 13 (17%) produced colicins other than Col V, and 11 (14.5%) produced Col V only. Trimethoprim/Sulfa (72%), ampicillin (64.5%), enrofloxacin (55.3%), and ciprofloxacin (47.4%) were the major antimicrobial resistance frequencies observed. Twenty-five different multiresistance patterns were observed, where sixty-six strains (86.8%) were included. A MIC test showed that most of the strains were sensitive to low gentamicin and kanamycin concentrations, whereas most of the strains were resistant to tetracycline. An invasiveness assay showed that the predominant alterations caused to HEp-2 cells were changes in shape and staining, and in most of the specimens, a partial monolayer detachment was also seen. Fifteen strains invaded more than 30% of the monolayer cells, causing the formation of intercellular bridges or filipoidal-like protrusions. The results suggest the existence of specific clone complexes derived from EIEC strains adapted to the avian host. To our knowledge, this is the first study that demonstrates the presence of extraintestinal invasive E. coli (ExIEC) strains.

Detección precoz de la colonización de catéteres venosos tunelizados en pacientes en una unidad de hemodiálisis. Eficacia del sellado con antibiótico para erradicar dicha colonización / Early detection of the colonization of tunnelised venous catheters in patients in a haemodialysis unit. Efficacy of antibiotic sealing to eradicate the colonisation

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Enteroaggregative Escherichia coli an emergent pathogen with different virulence properties.

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.

Prevalence of Escherichia coli O157 in cattle and swine in central Mexico.

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.

Serotyping and virulence genes detection in Escherichia coli isolated from fertile and infertile eggs, dead-in-shell embryos, and chickens with yolk sac infection.

Escherichia coli is a common avian pathogen mainly associated with extraintestinal infections such as yolk sac infection (YSI). The aim of this study was to determine the serotypes and the presence of some virulence genes of E. coli strains isolated from different samples in a vertically integrated poultry operation in Mexico. Two hundred sixty-seven E. coli isolates from different samples were serotyped using rabbit serum against the 175 somatic (O) and 56 flagellar (H) antigens of the typing schema. Virulence genes were determined by colony blot hybridization, using DNA probes for st, eae, agg1, agg2, bfp, lt, cdt, slt, and ipaH diarrhea-associated virulence factors. The serogroup of 85% of the strains was determined; O19 (12%), 084 (9%), 08 (6%), and 078 (5%) were the most common. Using the complete antigenic formula (O and H), O19:NM (n = 31) was the serotype most frequently isolated from dead-in-shell embryos and in broilers that had died on the fourth, fifth, sixth, and seventh days after hatch. One hundred ten strains (41.2%) hybridized with one or more of the used probes. Of these, ipaH (72%), eae (30%), and cdt (27%) were the most common. Considering the origin of the respective isolates, 40% of the broiler farm strains were positive for at least one probe. Results show that some avian E. coli strains isolated in Mexico are included in avian pathogenic E. coli serotypes not previously reported, suggesting that they could be specific for this geographic area. The wide distribution of the ipaH gene among nonmotile strains suggests that this invasiveness trait could be important in YSI pathogenesis. On the other hand, some other genes could contribute to E. coli virulence during YSI.

Promoción y prevención en el sistema de salud / Promotion and prevention in Colombiaïs health system

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.