Analysis of the Virulence of an Atypical Enteropathogenic Escherichia coli Strain In Vitro and In Vivo and the Influence of Type Three Secretion System

Atypical enteropathogenic Escherichia coli (aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytes in vitro (Caco-2 cells) and in vivo (rabbit ileal loops) and to translocate the rat intestinal mucosa in vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potential in vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasion in vitro and in vivo and to bacterial translocation to extraintestinal sites

Os livros brancos da defesa da República Popular da China 1998-2010

Este estudo é uma análise da evolução das perceções de (in)segurança da República Popular da China (RPC), através da aferição quantitativa e qualitativa de expressões idiomáticas caracterizadoras da evolução do sistema internacional, as quais foram selecionadas e associadas a tais perceções, e que constam das sete edições do Livro Branco da Defesa publicadas pelo Conselho de Estado entre 1998 e 2010. Procura-se através de um enquadramento conceptual e metodológico derivado da análise crítica do discurso baseado nas teorias de Michel Foucault e de Norman Fairclough, bem como do da perceção de ameaças por parte dos Estados no sistema internacional formulado por Robert Jervis, identificar e justificar variações nas perceções de (in)segurança da RPC entre 1998 e 2010, concluindo-se que estas refletem uma visão de natureza essencialmente realista estrutural e Lockeana quanto à evolução do sistema internacional

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Dilemas éticos en el ejercicio de la psicología: resultados de una investigación

El presente trabajo arroja los resultados de una investigación que relevó el posicionamiento de psicólogos de la ciudad de Mar del Plata respecto de las normas deontológicas que regulan su ejercicio profesional. En particular en aquellos temas en que los profesionales se enfrentan a situaciones de difícil resolución, como lo son las relaciones extraterapéuticas y el abuso de menores

Dilemas éticos en el ejercicio de la psicología: resultados de una investigación

El presente trabajo arroja los resultados de una investigación que relevó el posicionamiento de psicólogos de la ciudad de Mar del Plata respecto de las normas deontológicas que regulan su ejercicio profesional. En particular en aquellos temas en que los profesionales se enfrentan a situaciones de difícil resolución, como lo son las relaciones extraterapéuticas y el abuso de menores

A new method for producing highly concentrated non-aqueous dispersions of silver nanoparticles and the evaluation of their bactericidal activity

Different preparation methods of silver nanoparticles (AgNP) are well described in the literature, most of them in aqueous medium. Aqueous dispersions of AgNP normally have a limited capacity to tolerate high nanosilver concentrations. However, AgNP production in non-aqueous medium is still scarce although its exploitation for example, as coating for hydrophobic surfaces, would be of a huge importance in many technological applications. in this work, we report the chemical preparation of highly concentrated non-aqueous AgNP dispersions obtained by reduction of silver cation, from two distinct salt sources (AgNO3 and AgBF4), by 1-butanol in the presence of a biocompatible poly(ether-block-amide) copolymer, named PEBA. the highest concentration reached was around 5 mM, when it used AgBF4 as silver source and 4 % (w/w) of a PEBA solution in 1-butanol. This AgNP concentration is notably higher than the values reported in aqueous medium. the AgNP formation was attested by UV-Vis spectroscopic analysis, which showed the characteristic strong plasmon band at 420 nm. the X-ray diffraction patterns confirmed the formation of a crystalline fcc silver metallic phase with particle diameters ranging from 5 to 10 nm accordingly to transmission electron microscopy examination. It was also observed that the AgNP dimensions are dependent on the PEBA and silver salt concentrations. the AgNP dispersions presented a very high antimicrobial activity against E. coli and S. aureus microorganisms, even in low concentration, attested by the Kirby-Bauer method.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Lab Mat Hibridos, Inst Ciencias Ambientais Quim & Farmaceut, BR-09913030 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cirurgia, Lab Transplante Expt Orgaos, BR-09913030 São Paulo, BrazilUniversidade Federal de São Paulo, Lab Mat Hibridos, Inst Ciencias Ambientais Quim & Farmaceut, BR-09913030 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cirurgia, Lab Transplante Expt Orgaos, BR-09913030 São Paulo, BrazilCNPq: 483878/2011-1Web of Scienc

MICROCIRCULATORY EVALUATION in SEPSIS: A DIFFICULT TASK

Microcirculatory dysfunction plays a pivotal role in the pathogenesis of severe sepsis and septic shock; hence, microcirculation blood flow monitoring has gained increasing attention. However, microcirculatory imaging is still investigational in human sepsis and has not yet been incorporated into routine clinical practice for several reasons, including the difficult interpretation of microcirculation imaging data, difficulty to draw a parallel between sublingual microcirculation imaging and organ microcirculation dysfunction, as well as the absence of microvessel dysfunction parameters defining sequential microcirculatory changes from the early to late stages of the disease, which could aid in the context of therapeutic approaches and of prognostic parameters. the purpose of this review was to bridge the experimental abdominal organ microvascular derangement kinetics and clinical aspects of microcirculatory findings in the early phase of severe sepsis/septic shock.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Surg, BR-04039032 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Surg, BR-04039032 São Paulo, BrazilWeb of Scienc

Ozonated Mineral Oil: Preparation, Characterization and Evaluation of the Microbicidal Activity

<p>The ozonation of vegetable oils has been studied, since the produced ointments have antibacterial and fungicidal activities. However, the ozonation of mineral oils has not been reported in the literature yet, opening an interesting field for examination. In this work, we have shown the ozonation of a commercial mineral oil (Nujol). The main goal was to produce oils containing free ozone, so that this gas could act as antimicrobial agent. It was found that in Nujol, ozone remains for at least 40 days and in the sample ozonized for 15 h its concentration was 7.5 mg mL⁻¹. Neat Nujol showed no antimicrobial activity against the tested microorganisms, however, when ozonated it showed antimicrobial activity against <i>Enterococcus faecalis, Staphylococcus aureus</i> and <i>Escherichia coli</i>.</p

<i>Escherichia albertii</i>, a novel human enteropathogen, colonizes rat enterocytes and translocates to extra-intestinal sites

<div><p>Diarrhea is the second leading cause of death of children up to five years old in the developing countries. Among the etiological diarrheal agents are atypical enteropathogenic <i>Escherichia coli</i> (aEPEC), one of the diarrheagenic <i>E</i>. <i>coli</i> pathotypes that affects children and adults, even in developed countries. Currently, genotypic and biochemical approaches have helped to demonstrate that some strains classified as aEPEC are actually <i>E</i>. <i>albertii</i>, a recently recognized human enteropathogen. Studies on particular strains are necessary to explore their virulence potential in order to further understand the underlying mechanisms of <i>E</i>. <i>albertii</i> infections. Here we demonstrated for the first time that infection of fragments of rat intestinal mucosa is a useful tool to study the initial steps of <i>E</i>. <i>albertii</i> colonization. We also observed that an <i>E</i>. <i>albertii</i> strain can translocate from the intestinal lumen to Mesenteric Lymph Nodes and liver in a rat model. Based on our finding of bacterial translocation, we investigated how <i>E</i>. <i>albertii</i> might cross the intestinal epithelium by performing infections of M-like cells <i>in vitro</i> to identify the potential <i>in vivo</i> translocation route. Altogether, our approaches allowed us to draft a general <i>E</i>. <i>albertii</i> infection route from the colonization till the bacterial spreading <i>in vivo</i>.</p></div

Bacterial strains.

<p>Bacterial strains.</p