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1.
Nat Immunol ; 19(12): 1309-1318, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30397349

RESUMEN

The unique cell biology of Toll-like receptor 4 (TLR4) allows it to initiate two signal-transduction cascades: a signal dependent on the adaptors TIRAP (Mal) and MyD88 that begins at the cell surface and regulates proinflammatory cytokines, and a signal dependent on the adaptors TRAM and TRIF that begins in the endosomes and drives the production of type I interferons. Negative feedback circuits to limit TLR4 signals from both locations are necessary to balance the inflammatory response. We describe a negative feedback loop driven by autocrine-paracrine prostaglandin E2 (PGE2) and the PGE2 receptor EP4 that restricted TRIF-dependent signals and the induction of interferon-ß through the regulation of TLR4 trafficking. Inhibition of PGE2 production or antagonism of EP4 increased the rate at which TLR4 translocated to endosomes and amplified TRIF-dependent activation of the transcription factor IRF3 and caspase-8. This PGE2-driven mechanism restricted TLR4-TRIF signaling in vitro after infection of macrophages by the Gram-negative pathogens Escherichia coli or Citrobacter rodentium and protected mice against mortality induced by Salmonella enteritidis serovar Typhimurium. Thus, PGE2 restricted TLR4-TRIF signaling specifically in response to lipopolysaccharide.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/inmunología , Dinoprostona/inmunología , Inmunidad Innata/inmunología , Transducción de Señal/inmunología , Receptor Toll-Like 4/inmunología , Animales , Infecciones Bacterianas/inmunología , Retroalimentación Fisiológica/fisiología , Humanos , Lipopolisacáridos/inmunología , Lipopolisacáridos/toxicidad , Ratones , Ratones Endogámicos C57BL , Células THP-1
2.
Mol Microbiol ; 108(5): 536-550, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29509331

RESUMEN

Enteropathogenic Escherichia coli (EPEC) use a type 3 secretion system (T3SS) for injection of effectors into host cells and intestinal colonization. Here, we demonstrate that the multicargo chaperone CesT has two strictly conserved tyrosine phosphosites, Y152 and Y153 that regulate differential effector secretion in EPEC. Conservative substitution of both tyrosine residues to phenylalanine strongly attenuated EPEC type 3 effector injection into host cells, and limited Tir effector mediated intimate adherence during infection. EPEC expressing a CesT Y152F variant were deficient for NleA effector expression and exhibited significantly reduced translocation of NleA into host cells during infection. Other effectors were observed to be dependent on CesT Y152 for maximal translocation efficiency. Unexpectedly, EPEC expressing a CesT Y153F variant exhibited significantly enhanced effector translocation of many CesT-interacting effectors, further implicating phosphosites Y152 and Y153 in CesT functionality. A mouse infection model of intestinal disease using Citrobacter rodentium revealed that CesT tyrosine substitution variants displayed delayed colonization and were more rapidly cleared from the intestine. These data demonstrate genetically separable functions for tandem tyrosine phosphosites within CesT. Therefore, CesT via its C-terminal tyrosine phosphosites, has relevant roles beyond typical type III secretion chaperones that interact and stabilize effector proteins.


Asunto(s)
Escherichia coli Enteropatógena/patogenicidad , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/metabolismo , Chaperonas Moleculares/metabolismo , Organofosfatos/metabolismo , Polímeros/metabolismo , Factores de Virulencia/metabolismo , Animales , Modelos Animales de Enfermedad , Escherichia coli Enteropatógena/genética , Escherichia coli O157 , Proteínas de Escherichia coli/genética , Femenino , Células HeLa , Humanos , Enfermedades Intestinales/microbiología , Ratones , Ratones Endogámicos C57BL , Chaperonas Moleculares/genética , Tirosina/genética , Virulencia/genética , Factores de Virulencia/genética
3.
PLoS Pathog ; 9(6): e1003403, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23785281

RESUMEN

While phosphotyrosine modification is an established regulatory mechanism in eukaryotes, it is less well characterized in bacteria due to low prevalence. To gain insight into the extent and biological importance of tyrosine phosphorylation in Escherichia coli, we used immunoaffinity-based phosphotyrosine peptide enrichment combined with high resolution mass spectrometry analysis to comprehensively identify tyrosine phosphorylated proteins and accurately map phosphotyrosine sites. We identified a total of 512 unique phosphotyrosine sites on 342 proteins in E. coli K12 and the human pathogen enterohemorrhagic E. coli (EHEC) O157:H7, representing the largest phosphotyrosine proteome reported to date in bacteria. This large number of tyrosine phosphorylation sites allowed us to define five phosphotyrosine site motifs. Tyrosine phosphorylated proteins belong to various functional classes such as metabolism, gene expression and virulence. We demonstrate for the first time that proteins of a type III secretion system (T3SS), required for the attaching and effacing (A/E) lesion phenotype characteristic for intestinal colonization by certain EHEC strains, are tyrosine phosphorylated by bacterial kinases. Yet, A/E lesion and metabolic phenotypes were unaffected by the mutation of the two currently known tyrosine kinases, Etk and Wzc. Substantial residual tyrosine phosphorylation present in an etk wzc double mutant strongly indicated the presence of hitherto unknown tyrosine kinases in E. coli. We assess the functional importance of tyrosine phosphorylation and demonstrate that the phosphorylated tyrosine residue of the regulator SspA positively affects expression and secretion of T3SS proteins and formation of A/E lesions. Altogether, our study reveals that tyrosine phosphorylation in bacteria is more prevalent than previously recognized, and suggests the involvement of phosphotyrosine-mediated signaling in a broad range of cellular functions and virulence.


Asunto(s)
Escherichia coli Enteropatógena/metabolismo , Escherichia coli K12/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de la Membrana/metabolismo , Fosfotirosina/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Proteoma/metabolismo , Escherichia coli Enteropatógena/genética , Escherichia coli K12/genética , Proteínas de Escherichia coli/genética , Proteínas de la Membrana/genética , Fosfotirosina/genética , Proteínas Tirosina Quinasas/genética , Proteoma/genética , Transducción de Señal/fisiología
4.
J Infect Dis ; 210(12): 1909-19, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-25038258

RESUMEN

BACKGROUND: A Shiga toxin type 2a (Stx2a)-producing enteroaggregative Escherichia coli (EAEC) strain of serotype O104:H4 caused a large outbreak in 2011 in northern Europe. Pathogenic mechanisms for this strain are unclear. We hypothesized that EAEC genes encoded on the pAA virulence plasmid promoted the translocation of Stx2a across the intestinal mucosa. METHODS: We investigated the potential contribution of pAA by using mutants of Stx-EAEC strain C227-11, either cured of the pAA plasmid or deleted for individual known pAA-encoded virulence genes (ie, aggR, aggA, and sepA). The resulting mutants were tested for their ability to induce interleukin 8 (IL-8) secretion and translocation of Stx2a across a polarized colonic epithelial (T84 cell) monolayer. RESULTS: We found that deletion of aggR or aggA significantly reduced bacterial adherence and (independently) translocation of Stx2a across the T84-cell monolayer. Moreover, deletion of aggR, aggA, sepA, or the Stx2a-encoding phage from C227-11 resulted in reduced secretion of IL-8 from the infected monolayer. CONCLUSIONS: Our data suggest that the AggR-regulated aggregative adherence fimbriae I enhance inflammation and enable the outbreak strain to both adhere to epithelial cells and translocate Stx2a across the intestinal epithelium.


Asunto(s)
Células Epiteliales/metabolismo , Escherichia coli/metabolismo , Transporte de Proteínas , Toxina Shiga II/metabolismo , Adhesión Bacteriana , Línea Celular , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Eliminación de Gen , Genotipo , Alemania , Humanos , Interleucina-8/metabolismo , Plásmidos , Serogrupo , Transactivadores/genética , Transactivadores/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
5.
Occup Ther Health Care ; 29(4): 370-82, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26053328

RESUMEN

Today, more than ever, occupational therapists are engaged in close partnerships with community organizations and community settings such as service agencies, refugee and immigrant enclaves, and faith-based organizations, to name a few, for the purpose of engaging in scholarship of practice. However, we know little about the views of community partners regarding the development and sustainability of university-community partnerships. The purpose of this article is twofold: First, we will describe a pilot study in which we gathered qualitative data from community partners engaged in scholarship of practice with faculty and students, regarding their views about benefits of partnerships, challenges, and characteristics of sustainable partnerships. Second, based on this pilot study and extensive experience of the authors, we propose a revised version of a partnerships model available in the literature. We illustrate the model through examples of the authors' collective experiences developing and sustaining successful university-community partnerships.


Asunto(s)
Relaciones Comunidad-Institución , Conducta Cooperativa , Investigación sobre Servicios de Salud , Terapia Ocupacional , Características de la Residencia , Investigación Biomédica Traslacional , Universidades , Actitud , Humanos , Proyectos Piloto , Desarrollo de Programa
6.
BMC Microbiol ; 12: 231, 2012 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-23051860

RESUMEN

BACKGROUND: Enterohemorrhagic Escherichia coli (EHEC) colonizes the intestinal epithelium and causes attaching and effacing (A/E) lesions. Expression of virulence genes, particularly those from the locus of the enterocyte effacement (LEE) pathogenicity island is required for the formation of a type three secretion system, which induces A/E lesion formation. Like other horizontally acquired genetic elements, expression of the LEE is negatively regulated by H-NS. In the non-pathogenic Escherichia coli K-12 strain the stringent starvation protein A (SspA) inhibits accumulation of H-NS, and thereby allows de-repression of the H-NS regulon during the stationary phase of growth. However, the effect of SspA on the expression of H-NS-controlled virulence genes in EHEC is unknown. RESULTS: Here we assess the effect of SspA on virulence gene expression in EHEC. We show that transcription of virulence genes including those of the LEE is decreased in an sspA mutant, rendering the mutant strain defective in forming A/E lesions. A surface exposed pocket of SspA is functionally important for the regulation of the LEE and for the A/E phenotype. Increased expression of ler alleviates LEE expression in an sspA mutant, suggesting that the level of Ler in the mutant is insufficient to counteract H-NS-mediated repression. We demonstrate that the H-NS level is two-fold higher in an sspA mutant compared to wild type, and that the defects of the sspA mutant are suppressed by an hns null mutation, indicating that hns is epistatic to sspA in regulating H-NS repressed virulence genes. CONCLUSIONS: SspA positively regulates the expression of EHEC virulence factors by restricting the intracellular level of H-NS. Since SspA is conserved in many bacterial pathogens containing horizontally acquired pathogenicity islands controlled by H-NS, our study suggests a common mechanism whereby SspA potentially regulates the expression of virulence genes in these pathogens.


Asunto(s)
Escherichia coli Enterohemorrágica/genética , Proteínas de Escherichia coli/metabolismo , Proteínas Fimbrias/metabolismo , Regulación Bacteriana de la Expresión Génica , Islas Genómicas , Factores de Virulencia/biosíntesis , Proteínas de Escherichia coli/genética , Proteínas Fimbrias/genética , Transcripción Genética
7.
Mol Microbiol ; 73(3): 446-65, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19570135

RESUMEN

Colonization of the intestinal epithelium by enterohaemorrhagic Escherichia coli (EHEC) is characterized by an attaching and effacing (A/E) histopathology. The locus of enterocyte effacement (LEE) pathogenicity island encodes many genes required for the A/E phenotype including the global regulator of EHEC virulence gene expression, Ler. The LEE is subject to a complex regulatory network primarily targeting ler transcription. The RNA chaperone Hfq, implicated in post-transcriptional regulation, is an important virulence factor in many bacterial pathogens. Although post-transcriptional regulation of EHEC virulence genes is known to occur, a regulatory role of Hfq in EHEC virulence gene expression has yet to be defined. Here, we show that an hfq mutant expresses increased levels of LEE-encoded proteins prematurely, leading to earlier A/E lesion formation relative to wild type. Hfq indirectly affects LEE expression in exponential phase independent of Ler by negatively controlling levels of the regulators GrlA and GrlR through post-transcriptional regulation of the grlRA messenger. Moreover, Hfq negatively affects LEE expression in stationary phase independent of GrlA and GrlR. Altogether, Hfq plays an important role in co-ordinating the temporal expression of the LEE by controlling grlRA expression at the post-transcriptional level.


Asunto(s)
Escherichia coli Enterohemorrágica/genética , Proteínas de Escherichia coli/metabolismo , Islas Genómicas , Proteína de Factor 1 del Huésped/metabolismo , Fosfoproteínas/metabolismo , Escherichia coli Enterohemorrágica/metabolismo , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Proteína de Factor 1 del Huésped/genética , Fosfoproteínas/genética , Procesamiento Postranscripcional del ARN , ARN Bacteriano/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transactivadores/genética , Transactivadores/metabolismo
8.
J Surg Oncol ; 99(8): 500-4, 2009 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-19466740

RESUMEN

This article describes the Danish National Indicator Project that aims to document and improve the quality of care at national level. Specific clinical indicators, standards, and prognostic factors have been developed for eight diseases (e.g. lung cancer). It has been implemented in all clinical departments in Denmark. Participation is mandatory. Results related to lung cancer are presented and discussed. The experiences from 2000 to 2008 indicate that the quality of care related to the eight diseases improve over time and that that performance and outcome measurement will get paid in terms of quality improvement.


Asunto(s)
Programas Nacionales de Salud/normas , Indicadores de Calidad de la Atención de Salud/organización & administración , Gestión de la Calidad Total/organización & administración , Auditoría Clínica , Dinamarca , Implementación de Plan de Salud , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Programas Nacionales de Salud/estadística & datos numéricos , Indicadores de Calidad de la Atención de Salud/estadística & datos numéricos , Sistema de Registros , Análisis de Supervivencia , Gestión de la Calidad Total/estadística & datos numéricos
9.
Front Microbiol ; 10: 1824, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31456767

RESUMEN

An O104:H4 Shiga toxin (Stx)-producing enteroaggregative Escherichia coli (EAEC) strain caused a large outbreak of bloody diarrhea and the hemolytic uremic syndrome in 2011. We previously developed an ampicillin (Amp)-treated C57BL/6 mouse model to measure morbidity (weight loss) and mortality of mice orally infected with the prototype Stx-EAEC strain C227-11. Here, we hypothesized that mice fed C227-11 cured of the pAA plasmid or deleted for individual genes on that plasmid would display reduced virulence compared to animals given the wild-type (wt) strain. C227-11 cured of the pAA plasmid or deleted for the known pAA-encoded virulence genes aggR, aggA, sepA, or aar were fed to Amp-treated C57BL/6 mice at doses of 1010-1011CFU. Infected animals were then either monitored for morbidity and lethality for 28 days or euthanized to determine intestinal pathology and colonization levels at selected times. The pAA-cured, aggR, and aggA mutants of strain C227-11 all showed reduced colonization at various intestinal sites. However, the aggR mutant was the only mutant attenuated for virulence as it showed both reduced morbidity and mortality. The aar mutant showed increased expression of the aggregative adherence fimbriae (AAF) and caused greater systemic effects in infected mice when compared to the C227-11 wt strain. However, unexpectedly, both the aggA and aar mutants displayed increased weight loss compared to wt. The sepA mutant did not exhibit altered morbidity or mortality in the Amp-treated mouse model compared to wt. Our data suggest that the increased morbidity due to the aar mutant could possibly be via an effect on expression of an as yet unknown virulence-associated factor under AggR control.

10.
J Bacteriol ; 190(3): 1084-96, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18039766

RESUMEN

The bacterial stringent response serves as a paradigm for understanding global regulatory processes. It can be triggered by nutrient downshifts or starvation and is characterized by a rapid RelA-dependent increase in the alarmone (p)ppGpp. One hallmark of the response is the switch from maximum-growth-promoting to biosynthesis-related gene expression. However, the global transcription patterns accompanying the stringent response in Escherichia coli have not been analyzed comprehensively. Here, we present a time series of gene expression profiles for two serine hydroxymate-treated cultures: (i) MG1655, a wild-type E. coli K-12 strain, and (ii) an isogenic relADelta251 derivative defective in the stringent response. The stringent response in MG1655 develops in a hierarchical manner, ultimately involving almost 500 differentially expressed genes, while the relADelta251 mutant response is both delayed and limited in scope. We show that in addition to the down-regulation of stable RNA-encoding genes, flagellar and chemotaxis gene expression is also under stringent control. Reduced transcription of these systems, as well as metabolic and transporter-encoding genes, constitutes much of the down-regulated expression pattern. Conversely, a significantly larger number of genes are up-regulated. Under the conditions used, induction of amino acid biosynthetic genes is limited to the leader sequences of attenuator-regulated operons. Instead, up-regulated genes with known functions, including both regulators (e.g., rpoE, rpoH, and rpoS) and effectors, are largely involved in stress responses. However, one-half of the up-regulated genes have unknown functions. How these results are correlated with the various effects of (p)ppGpp (in particular, RNA polymerase redistribution) is discussed.


Asunto(s)
Escherichia coli K12/genética , Proteínas de Escherichia coli/metabolismo , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica , Serina/análogos & derivados , Transcripción Genética , Escherichia coli K12/crecimiento & desarrollo , Escherichia coli K12/metabolismo , Escherichia coli K12/fisiología , Proteínas de Escherichia coli/genética , Respuesta al Choque Térmico , Ligasas/genética , Serina/farmacología
11.
Can J Diet Pract Res ; 69(4): 203-7, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19063811

RESUMEN

PURPOSE: An n-3 polyunsaturated fatty acid (PUFA) supplement was incorporated into three food products previously determined to be preferred by cancer patients, and overall acceptability of these foods was evaluated. METHODS: Preliminary testing was performed; an internal panel determined initial acceptability of foods with the supplement added. Taste panel evaluations were held at the Cross Cancer Institute in Edmonton, Alberta. Each participant completed a questionnaire rating aroma, flavour, and overall acceptance on a seven-point hedonic scale (1 = dislike extremely, 7 = like extremely), as well as ability to consume each food daily. RESULTS: Foods were well-liked by patients and non-patients. Mean +/- standard deviation acceptance scores for the three foods were pasta sauce 5.9 +/- 0.94 (n=90), oatmeal 6.1 +/- 0.88 (n=79), and smoothie 5.9 +/- 1.12 (n=126). Overall, 94% of patients and non-patients gave tomato pasta sauce, oatmeal, and the smoothie an acceptance score of at least 5. CONCLUSIONS: The supplement was incorporated successfully into three foods, which were highly accepted by patients with cancer. Further research should focus on incorporating the supplement into flavoured or sweet foods, as these appear most effective. Microencapsulated fish oil in food products may be used as an alternative to fish oil capsules for delivering n-3 PUFA in clinical trials.


Asunto(s)
Ácidos Grasos Omega-3/administración & dosificación , Preferencias Alimentarias/psicología , Alimentos Fortificados , Satisfacción del Paciente , Gusto/fisiología , Cápsulas , Composición de Medicamentos , Aceites de Pescado/administración & dosificación , Tecnología de Alimentos/métodos , Alimentos Orgánicos , Humanos , Neoplasias/dietoterapia , Valor Nutritivo , Encuestas y Cuestionarios
12.
mBio ; 9(1)2018 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-29487233

RESUMEN

Enteric pathogens with low infectious doses rely on the ability to orchestrate the expression of virulence and metabolism-associated genes in response to environmental cues for successful infection. Accordingly, the human pathogen enterohemorrhagic Escherichia coli (EHEC) employs a complex multifaceted regulatory network to link the expression of type III secretion system (T3SS) components to nutrient availability. While phosphorylation of histidine and aspartate residues on two-component system response regulators is recognized as an integral part of bacterial signaling, the involvement of phosphotyrosine-mediated control is minimally explored in Gram-negative pathogens. Our recent phosphotyrosine profiling study of E. coli identified 342 phosphorylated proteins, indicating that phosphotyrosine modifications in bacteria are more prevalent than previously anticipated. The present study demonstrates that tyrosine phosphorylation of a metabolite-responsive LacI/GalR family regulator, Cra, negatively affects T3SS expression under glycolytic conditions that are typical for the colonic lumen environment where production of the T3SS is unnecessary. Our data suggest that Cra phosphorylation affects T3SS expression by modulating the expression of ler, which encodes the major activator of EHEC virulence gene expression. Phosphorylation of the Cra Y47 residue diminishes DNA binding to fine-tune the expression of virulence-associated genes, including those of the locus of enterocyte effacement pathogenicity island that encode the T3SS, and thereby negatively affects the formation of attaching and effacing lesions. Our data indicate that tyrosine phosphorylation provides an additional mechanism to control the DNA binding of Cra and other LacI/GalR family regulators, including LacI and PurR. This study describes an initial effort to unravel the role of global phosphotyrosine signaling in the control of EHEC virulence potential.IMPORTANCE Enterohemorrhagic Escherichia coli (EHEC) causes outbreaks of hemorrhagic colitis and the potentially fatal hemolytic-uremic syndrome. Successful host colonization by EHEC relies on the ability to coordinate the expression of virulence factors in response to environmental cues. A complex network that integrates environmental signals at multiple regulatory levels tightly controls virulence gene expression. We demonstrate that EHEC utilizes a previously uncharacterized phosphotyrosine signaling pathway through Cra to fine-tune the expression of virulence-associated genes to effectively control T3SS production. This study demonstrates that tyrosine phosphorylation negatively affects the DNA-binding capacity of Cra, which affects the expression of genes related to virulence and metabolism. We demonstrate for the first time that phosphotyrosine-mediated control affects global transcription in EHEC. Our data provide insight into a hitherto unexplored regulatory level of the global network controlling EHEC virulence gene expression.


Asunto(s)
Escherichia coli Enterohemorrágica/metabolismo , Escherichia coli Enterohemorrágica/patogenicidad , Proteínas de Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Fosfotirosina/metabolismo , Procesamiento Proteico-Postraduccional , Humanos , Fosforilación , Sistemas de Secreción Tipo III/metabolismo , Virulencia , Factores de Virulencia/metabolismo
13.
Cell Mol Gastroenterol Hepatol ; 2(1): 48-62.e3, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26855967

RESUMEN

BACKGROUND AND AIMS: Enterohemorrhagic E. coli (EHEC) causes over 70,000 episodes of foodborne diarrhea annually in the USA. The early sequence of events which precede life-threatening hemorrhagic colitis and hemolytic uremic syndrome are not fully understood due to the initial asymptomatic phase of the disease and the lack of a suitable animal model. The aim of this study was to determine the initial molecular events in the interaction between EHEC and human colonic epithelium. METHODS: Human colonoids derived from adult proximal colonic stem cells were developed into monolayers to study EHEC-epithelial interactions. Monolayer confluency and differentiation were monitored by transepithelial electrical resistance (TER) measurements. The monolayers were apically infected with EHEC and the progression of epithelial damage over time was assessed using biochemical and imaging approaches. RESULTS: Human colonoid cultures recapitulate the differential protein expression patterns characteristic of the crypt and surface colonocytes. Mucus-producing differentiated colonoid monolayers are preferentially colonized by EHEC. Upon colonization, EHEC forms characteristic attaching and effacing lesions on the apical surface of colonoid monolayers. Mucin 2, a main component of colonic mucus, and protocadherin 24 (PCDH24), a microvillar resident protein, are targeted by EHEC at early stages of infection. The EHEC secreted serine protease, EspP, initiates brush border damage through PCDH24 reduction. CONCLUSIONS: Human colonoid monolayers are a relevant pathophysiological model which allows the study of early molecular events during enteric infections. Colonoid monolayers provide access to both apical and basolateral surfaces, thus providing an advantage over 3D cultures to study host-pathogen interactions in a controllable and tractable manner. EHEC reduces colonic mucus and affects the brush border cytoskeleton in the absence of commensal bacteria.

14.
Work ; 25(3): 241-52, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16179773

RESUMEN

The homeless population in the US has dramatically increased in the past two decades. People who are homeless often lack skills sets such as stress management and social skills, independent living skills, and skills for vocational and leisure engagement. Best practice vocational education and training programs for individuals who are homeless recognize that success in the worker role often hinges on a person's capacity to manage day-to-day living. Life skills and pre-employment training are essential components of vocational programs but no more important than interpersonal skill development including anger management, developing self esteem and motivation, building goal setting capacity, and skills for money management, personal budgeting and self-advocacy. These areas of performance have all been traditionally included in occupational therapy's domain of practice. This article describes Project Employ, a grant funded supportive employment program that has grown out of collaboration between Duquesne University's Department of Occupational Therapy and Bethlehem Haven, an emergency shelter and residential recovery program and primary service provider for homeless people in Pittsburgh, Pennsylvania. The purpose of this article is to describe the history, structure and outcomes of Project Employ.


Asunto(s)
Servicios de Salud Comunitaria/organización & administración , Empleo , Personas con Mala Vivienda , Terapia Ocupacional/organización & administración , Rehabilitación Vocacional , Femenino , Humanos , Masculino , Desarrollo de Programa , Problemas Sociales
15.
Occup Ther Int ; 22(3): 152-62, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26284574

RESUMEN

The World Federation of Occupational Therapists (WFOT) and the American Occupational Therapy Association promote a globally connected profession that responds to the needs of our diverse societies. Global partnerships are grounded on the principle that cross-cultural experiences are enriching and provide mutual benefits. The purpose of this study was to uncover how occupational therapy educators and scholars perceive and experience (1) developing and sustaining global partnerships and (2) lessons learned. In this qualitative study, 30 occupational therapy educators and researchers completed an online survey. Eight participated in an interview. Results found major themes that help develop and sustain partnerships: building relationship of trust and respect, communicating effectively, cultivating cultural competence, sharing power and resources with collaborators and creating a context for reciprocal learning. Lessons learned include a call to walking humbly, building relationships of trust and respect, establishing open and honest communication, supporting local solutions to local problems, ensuring equality of resources and learning from their global partners. The findings suggest that global partnerships have the potential to transform both partners if the partners engage with mutual understanding and respect. Limitations of this study include a small sample size and participant's pool limited to occupational therapists from United States. Recommendations for future research include qualitative studies to identify model occupational therapy programmes that sustain global partnerships using a diverse sample of international occupational therapy educators and researchers.


Asunto(s)
Técnicos Medios en Salud/organización & administración , Competencia Cultural/educación , Salud Global/educación , Relaciones Interprofesionales , Terapia Ocupacional/organización & administración , Técnicos Medios en Salud/educación , Conducta Cooperativa , Curriculum , Humanos , Internet , Terapia Ocupacional/educación , Investigación Cualitativa
16.
Afr J Disabil ; 3(1): 112, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-28730000

RESUMEN

BACKGROUND: This qualitative-exploratory study examined the barriers to participation amongst children with disabilities in Lusaka, Zambia, from the mothers' perspective. OBJECTIVES: The objectives of this study were to understand how mothers of children with physical and cognitive disabilities who engaged their children in community-based rehabilitation (CBR) services in Lusaka, Zambia, perceived and described (1) the level of support they received and the barriers they encountered in terms of their child's meaningful social participation; (2) the use and awareness of these barriers to identify and pursue advocacy strategies; and (3) hopes for their child's future. METHODS: Data were collected through semi-structured interviews with each mother in her home. Results: Findings revealed both support and barriers to the child's social participation in relationship to their family, friends and community. Support also came from the CBR programme and mothers' personal resourcefulness. Mothers identified their child's school, their immediate environment and financial burdens as barriers to participation as well as their own personal insecurities and fears. Strategies to overcome barriers included internal and external actions. The mothers involved in the study hope their child's abilities will improve with continued CBR services. Some mothers described a bleak future for their child due to a lack of acceptance and access to education. CONCLUSION: The findings of this study suggest the significant role the mother of a child with a disability plays in her child's social participation. Recommendations include enhancing CBR programming for families, especially for mothers, and advocating on behalf of children with disabilities and their families to attract the attention of policy makers.

17.
PLoS One ; 9(1): e86618, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24466172

RESUMEN

BACKGROUND: Enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli are important causes of morbidity and mortality worldwide. These enteric pathogens contain a type III secretion system (T3SS) responsible for the attaching and effacing (A/E) lesion phenotype. The T3SS is encoded by the locus of enterocyte effacement (LEE) pathogenicity island. The H-NS-mediated repression of LEE expression is counteracted by Ler, the major activator of virulence gene expression in A/E pathogens. A regulator present in EPEC, H-NST, positively affects expression of H-NS regulon members in E. coli K-12, although the effect of H-NST on LEE expression and virulence of A/E pathogens has yet-to-be determined. RESULTS: We examine the effect of H-NST on LEE expression and A/E lesion formation on intestinal epithelial cells. We find that H-NST positively affects the levels of LEE-encoded proteins independently of ler and induces A/E lesion formation. We demonstrate H-NST binding to regulatory regions of LEE1 and LEE3, the first report of DNA-binding by H-NST. We characterize H-NST mutants substituted at conserved residues including Ala16 and residues Arg60 and Arg63, which are part of a potential DNA-binding domain. The single mutants A16V, A16L, R60Q and the double mutant R60Q/R63Q exhibit a decreased effect on LEE expression and A/E lesion formation. DNA mobility shift assays reveal that these residues are important for H-NST to bind regulatory LEE DNA targets. H-NST positively affects Ler binding to LEE DNA in the presence of H-NS, and thereby potentially helps Ler displace H-NS bound to DNA. CONCLUSIONS: H-NST induces LEE expression and A/E lesion formation likely by counteracting H-NS-mediated repression. We demonstrate that H-NST binds to DNA and identify arginine residues that are functionally important for DNA-binding. Our study suggests that H-NST provides an additional means for A/E pathogens to alleviate repression of virulence gene expression by H-NS to promote virulence capabilities.


Asunto(s)
Enterocitos/microbiología , Escherichia coli Enterohemorrágica/genética , Escherichia coli Enteropatógena/genética , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/genética , Islas Genómicas/genética , Línea Celular Tumoral , Proteínas de Unión al ADN/genética , Células Epiteliales/microbiología , Células HeLa , Humanos , Mucosa Intestinal/microbiología , Mutación/genética
18.
Work ; 45(1): 41-58, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23531570

RESUMEN

OBJECTIVE: This article presents a service learning pedagogy whereby students develop the skills of an evidence-based practice scholar committed to occupational justice as a means to transform occupational therapy practice, their clients, themselves and the world. PARTICIPANTS: Fifty-four fourth year occupational therapy students in a five-year master's program. METHODS: During a two-semester course in clinical reasoning, occupational therapy students participate in service learning with marginalized and vulnerable populations. During the fall semester, students spend time each week observing the population and staff, and conducting a needs assessment. At the end of the fall semester, students propose a ten-week evidence-based, occupation-focused program. During the spring semester, students carry out this project with an occupational justice lens. RESULTS: Through qualitative analysis of guided reflections and a final service-learning report students identify links between clinical reasoning and occupational justice theories and practice in a community context and carryout an advocacy plan to promote justice. CONCLUSIONS: Given the opportunity to learn new skills in a natural context with a vulnerable population, students demonstrate an understanding of occupational injustices and advocate for the rights of those they serve, witnessing the resulting changes in policies and practice within the community agency and beyond.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Necesidades y Demandas de Servicios de Salud , Terapia Ocupacional/educación , Aprendizaje Basado en Problemas/métodos , Estudiantes del Área de la Salud/psicología , Femenino , Humanos , Masculino , Servicios de Salud del Trabajador , Terapia Ocupacional/métodos , Poblaciones Vulnerables
19.
Afr J Disabil ; 2(1): 48, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-28729989

RESUMEN

BACKGROUND: This article describes a partnership between a community-based rehabilitation organisation and a non-governmental organisation (NGO) in Tanzania. The partnership focused on income-generating (IG) activities to tackle the problems of poverty faced by families with a child with a disability (CWD). OBJECTIVES: The aim of this case study was to describe the partnership between Comprehensive Community Based Rehabilitation Tanzania in Moshi (CCBRT-Moshi), a non-governmental organisation, and families to create an income-generating business, namely raising goats. METHOD: This was a team approach between CCBRT-Moshi and Heifer International, an organisation that focuses on IG activities to create a synergy or partnership between community-based rehabilitation and IG activities. RESULTS: This partnership between occupational therapy rehabilitation services at CCBRT-Moshi and the NGO resulted in strengthening the effectiveness of occupational therapy services and leaving a more lasting impact on the people they served within the community by helping to reduce poverty in addition to providing rehabilitation and prevention interventions. CONCLUSION: This collaboration was successful as it provided a means for families to generate income from raising goats. Although the results have not been empirically verified, observational and anecdotal evidence suggests that families with CWDs have better quality of life and ultimately improved health through this synergistic partnership.

20.
PLoS One ; 8(7): e69196, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23874912

RESUMEN

Life-threatening intestinal and systemic effects of the Shiga toxins produced by enterohemorrhagic Escherichia coli (EHEC) require toxin uptake and transcytosis across intestinal epithelial cells. We have recently demonstrated that EHEC infection of intestinal epithelial cells stimulates toxin macropinocytosis, an actin-dependent endocytic pathway. Host actin rearrangement necessary for EHEC attachment to enterocytes is mediated by the type 3 secretion system which functions as a molecular syringe to translocate bacterial effector proteins directly into host cells. Actin-dependent EHEC attachment also requires the outer membrane protein intimin, a major EHEC adhesin. Here, we investigate the role of type 3 secretion in actin turnover occurring during toxin macropinocytosis. Toxin macropinocytosis is independent of EHEC type 3 secretion and intimin attachment. EHEC soluble factors are sufficient to stimulate macropinocytosis and deliver toxin into enterocytes in vitro and in vivo; intact bacteria are not required. Intimin-negative enteroaggregative Escherichia coli (EAEC) O104:H4 robustly stimulate Shiga toxin macropinocytosis into intestinal epithelial cells. The apical macropinosomes formed in intestinal epithelial cells move through the cells and release their cargo at these cells' basolateral sides. Further analysis of EHEC secreted proteins shows that a serine protease EspP alone is able to stimulate host actin remodeling and toxin macropinocytosis. The observation that soluble factors, possibly serine proteases including EspP, from each of two genetically distinct toxin-producing strains, can stimulate Shiga toxin macropinocytosis and transcellular transcytosis alters current ideas concerning mechanisms whereby Shiga toxin interacts with human enterocytes. Mechanisms important for this macropinocytic pathway could suggest new potential therapeutic targets for Shiga toxin-induced disease.


Asunto(s)
Escherichia coli Enterohemorrágica/enzimología , Proteínas de Escherichia coli/metabolismo , Mucosa Intestinal/metabolismo , Pinocitosis/fisiología , Serina Endopeptidasas/metabolismo , Toxina Shiga/metabolismo , Actinas/metabolismo , Animales , Sistemas de Secreción Bacterianos/fisiología , Línea Celular , Técnica del Anticuerpo Fluorescente , Humanos , Íleon/citología , Íleon/metabolismo , Íleon/ultraestructura , Mucosa Intestinal/ultraestructura , Ratones , Microscopía Electrónica de Transmisión
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