1,523 research outputs found

    Long Polar Fimbriae Contribute to Colonization by \u3ci\u3eEscherichia coli\u3c/i\u3e O157:H7 In Vivo

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    The contribution of long polar fimbriae to intestinal colonization by Escherichia coli O157:H7 was evaluated in sheep, conventional pigs, and gnotobiotic piglets. E. coli O157:H7 strains with lpfA1 and lpfA2 mutated were recovered in significantly lower numbers and caused fewer attachment and effacement lesions than the parent strain

    Diversidad de enterobacterias asociadas a frutos de tomate (Lycopersi-cum sculentum Mill) y suelos de invernadero

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    The aim of this study was to evaluate the diversity of Enterobacteriaceae present in soil and tomato fruits from three greenhouses with fertirigation system. These crop systems are an important alternative for production in protected agriculture; however, there is little information about the microbiological quality of the fruit and its relationship with chemical soil characteristics. Soil evaluations consisted of analyzing organic matter content and pH. In the microbiological analysis were isolated and identified enterobacterias organisms from composite samples of soil and fruits at different stages of maturity (0, 50 and 100%). Culture media used was selective, differential and confirmatory testing with VITEK system. Enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC) were characterized genotypically, amplifying the lngA and bfpA genes by the technique of polymerase chain reaction (PCR). Diversity index (Simpson (D), Shannon-Wiener (H') and Chao estimator (SChao1) were calculated with the identified species. The species Enterobacter cloacae, Citrobacter freundii and C. brakii had a higher frequency of isolation, EPEC and ETEC were identified in soil samples and in fruits with 100% maturity. In soil, H' indices were positively correlated with the highest organic matter percentages. In fruit, although H 'and D showed less diverse bacterial communities, the isolation of ETEC and Shigella boydii on the fruit surface compromise their safety because they are usually consumed raw.El objetivo de este trabajo fue determinar la diversidad de enterobacterias presentes en suelo y tomates provenientes de tres invernaderos de fertirrigación. Estos sistemas de cultivo son una alternativa importante de producción en agricultura protegida, sin embargo, existe escasa información acerca de la calidad microbiológica de los frutos y su relación con las características químicas del suelo. Las evaluaciones del suelo consistieron en analizar el contenido de materia orgånica y pH. En los anålisis microbiológicos se aislaron e identificaron enterobacterias en muestras compuestas de suelo y frutos con diferentes grados de madurez (0, 50 y 100%), utilizando medios de cultivo selectivos, diferenciales y pruebas confirmatorias con el sistema VITEK. Los patogrupos de Escherichia coli enteropatogena (EPEC) y enterotoxigénica (ETEC) se caracterizaron genotípicamente mediante la técnica de reacción en cadena de la polimerasa (PCR), amplificåndose los genes bfpA y lngA. Con las especies identificadas se calcularon los índices de diversidad Simpson (D) y Shannon-Wiener (HŽ) y estimador de Chao (SChao1). Las especies Enterobacter cloacae, Citrobacter freundii y C. brakii presentaron mayor frecuencia de aislamiento, EPEC y ETEC fueron identificadas en muestras de suelo y en frutos con 100% de madurez. En suelo, los porcentajes de materia orgånica se correlacionaron positivamente con los índices HŽ. En fruto, aunque HŽ y D reflejaron comunidades bacterianas menos diversas, el aislamiento de ETEC y Shigella boydii sobre la superficie del fruto comprometen su inocuidad debido a que habitualmente se consume en forma cruda

    Diversidad de enterobacterias asociadas a frutos de tomate (Lycopersi-cum sculentum Mill) y suelos de invernadero

    Get PDF
    The aim of this study was to evaluate the diversity of Enterobacteriaceae present in soil and tomato fruits from three greenhouses with fertirigation system. These crop systems are an important alternative for production in protected agriculture; however, there is little information about the microbiological quality of the fruit and its relationship with chemical soil characteristics. Soil evaluations consisted of analyzing organic matter content and pH. In the microbiological analysis were isolated and identified enterobacterias organisms from composite samples of soil and fruits at different stages of maturity (0, 50 and 100%). Culture media used was selective, differential and confirmatory testing with VITEK system. Enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC) were characterized genotypically, amplifying the lngA and bfpA genes by the technique of polymerase chain reaction (PCR). Diversity index (Simpson (D), Shannon-Wiener (H') and Chao estimator (SChao1) were calculated with the identified species. The species Enterobacter cloacae, Citrobacter freundii and C. brakii had a higher frequency of isolation, EPEC and ETEC were identified in soil samples and in fruits with 100% maturity. In soil, H' indices were positively correlated with the highest organic matter percentages. In fruit, although H 'and D showed less diverse bacterial communities, the isolation of ETEC and Shigella boydii on the fruit surface compromise their safety because they are usually consumed raw.El objetivo de este trabajo fue determinar la diversidad de enterobacterias presentes en suelo y tomates provenientes de tres invernaderos de fertirrigación. Estos sistemas de cultivo son una alternativa importante de producción en agricultura protegida, sin embargo, existe escasa información acerca de la calidad microbiológica de los frutos y su relación con las características químicas del suelo. Las evaluaciones del suelo consistieron en analizar el contenido de materia orgånica y pH. En los anålisis microbiológicos se aislaron e identificaron enterobacterias en muestras compuestas de suelo y frutos con diferentes grados de madurez (0, 50 y 100%), utilizando medios de cultivo selectivos, diferenciales y pruebas confirmatorias con el sistema VITEK. Los patogrupos de Escherichia coli enteropatogena (EPEC) y enterotoxigénica (ETEC) se caracterizaron genotípicamente mediante la técnica de reacción en cadena de la polimerasa (PCR), amplificåndose los genes bfpA y lngA. Con las especies identificadas se calcularon los índices de diversidad Simpson (D) y Shannon-Wiener (HŽ) y estimador de Chao (SChao1). Las especies Enterobacter cloacae, Citrobacter freundii y C. brakii presentaron mayor frecuencia de aislamiento, EPEC y ETEC fueron identificadas en muestras de suelo y en frutos con 100% de madurez. En suelo, los porcentajes de materia orgånica se correlacionaron positivamente con los índices HŽ. En fruto, aunque HŽ y D reflejaron comunidades bacterianas menos diversas, el aislamiento de ETEC y Shigella boydii sobre la superficie del fruto comprometen su inocuidad debido a que habitualmente se consume en forma cruda

    New GOLD classification: longitudinal data on group assignment

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    Rationale: Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD). Objective: To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only. Methods: We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV1%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data. Results: At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722). Conclusions: In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index

    A Single Dose of a Hybrid hAdV5-Based Anti-COVID-19 Vaccine Induces a Long-Lasting Immune Response and Broad Coverage against VOC

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    Most approved vaccines against COVID-19 have to be administered in a prime/boost regimen. We engineered a novel vaccine based on a chimeric human adenovirus 5 (hAdV5) vector. The vaccine (named CoroVaxG.3) is based on three pillars: (i) high expression of Spike to enhance its immunodominance by using a potent promoter and an mRNA stabilizer; (ii) enhanced infection of muscle and dendritic cells by replacing the fiber knob domain of hAdV5 by hAdV3; (iii) use of Spike stabilized in a prefusion conformation. The transduction with CoroVaxG.3-expressing Spike (D614G) dramatically enhanced the Spike expression in human muscle cells, monocytes and dendritic cells compared to CoroVaxG.5 that expressed the native fiber knob domain. A single dose of CoroVaxG.3 induced a potent humoral immunity with a balanced Th1/Th2 ratio and potent T-cell immunity, both lasting for at least 5 months. Sera from CoroVaxG.3-vaccinated mice was able to neutralize pseudoviruses expressing B.1 (wild type D614G), B.1.117 (alpha), P.1 (gamma) and B.1.617.2 (delta) Spikes, as well as an authentic P.1 SARS-CoV-2 isolate. Neutralizing antibodies did not wane even after 5 months, making this kind of vaccine a likely candidate to enter clinical trials.Fil: López, M. Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Vinzon, Sabrina Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Cafferata, Eduardo Gustavo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Nuñez, Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Soto, Ariadna Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Sanchez Lamas, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Afonso, María Jimena. Fundación Instituto Leloir; ArgentinaFil: Aguilar Cortes, Diana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Rios, Gregorio David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Maricato, Juliana T.. Universidade Federal de Sao Paulo; BrasilFil: Torres Braconi, Carla. Universidade Federal de Sao Paulo; BrasilFil: Barbosa da Silveira, Vanessa. Universidade Federal de Sao Paulo; BrasilFil: Montes de Andrade, Tatiane. Universidade Federal de Sao Paulo; BrasilFil: Carvalho de Souza Bonetti, Tatiana. Universidade Federal de Sao Paulo; BrasilFil: Ramos Janini, Luiz M.. Universidade Federal de Sao Paulo; BrasilFil: Castello Girão, Manoel J. B.. Universidade Federal de Sao Paulo; BrasilFil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Gomez, Karina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ortega, Hugo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Berguer, Paula Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Podhajcer, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

    Boson-fermion stars: exploring different configurations

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    We use the flexibility of the concept of a fermion-boson star to explore different configurations, ranging from objects of atomic size and masses of the order 101810^{18} g, up to objects of galactic masses and gigantic halos around a smaller core, with possible interesting applications to astrophysics and cosmology, particularly in the context of dark matter.Comment: 8 pages. Minor changes, new reference added and a few typos correcte

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Atopic dermatitis and indoor use of energy sources in cooking and heating appliances

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    Background: Atopic dermatitis (AD) prevalence has considerably increased worldwide in recent years. Studying indoor environments is particularly relevant, especially in industrialised countries where many people spend 80% of their time at home, particularly children. This study is aimed to identify the potential association between AD and the energy source (biomass, gas and electricity) used for cooking and domestic heating in a Spanish schoolchildren population. Methods: As part of the ISAAC (International Study of Asthma and Allergies in Childhood) phase III study, a cross-sectional population-based survey was conducted with 21,355 6-to-7-year-old children from 8 Spanish ISAAC centres. AD prevalence, environmental risk factors and the use of domestic heating/cooking devices were assessed using the validated ISAAC questionnaire. Crude and adjusted odds ratios (cOR, aOR) and 95% confidence intervals (CIs) were obtained. A logistic regression analysis was performed (Chi-square test, p-value < 0.05). Results: It was found that the use of biomass systems gave the highest cORs, but only electric cookers showed a significant cOR of 1.14 (95% CI: 1.01-1.27). When the geographical area and the mother’s educational level were included in the logistic model, the obtained aOR values differed moderately from the initial cORs. Electric heating was the only type which obtained a significant aOR (1.13; 95% CI: 1.00-1.27). Finally, the model with all selected confounding variables (sex, BMI, number of siblings, mother’s educational level, smoking habits of parents, truck traffic and geographical area), showed aOR values which were very similar to those obtained in the previous adjusted logistic analysis. None of the results was statistically significant, but the use of electric heating showed an aOR close to significance (1.14; 95% CI: 0.99-1.31). Conclusion: In our study population, no statistically significant associations were found between the type of indoor energy sources used and the presence of AD

    A Ribosomal Misincorporation of Lys for Arg in Human Triosephosphate Isomerase Expressed in Escherichia coli Gives Rise to Two Protein Populations

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    We previously observed that human homodimeric triosephosphate isomerase (HsTIM) expressed in Escherichia coli and purified to apparent homogeneity exhibits two significantly different thermal transitions. A detailed exploration of the phenomenon showed that the preparations contain two proteins; one has the expected theoretical mass, while the mass of the other is 28 Da lower. The two proteins were separated by size exclusion chromatography in 3 M urea. Both proteins correspond to HsTIM as shown by Tandem Mass Spectrometry (LC/ESI-MS/MS). The two proteins were present in nearly equimolar amounts under certain growth conditions. They were catalytically active, but differed in molecular mass, thermostability, susceptibility to urea and proteinase K. An analysis of the nucleotides in the human TIM gene revealed the presence of six codons that are not commonly used in E. coli. We examined if they were related to the formation of the two proteins. We found that expression of the enzyme in a strain that contains extra copies of genes that encode for tRNAs that frequently limit translation of heterologous proteins (Arg, Ile, Leu), as well as silent mutations of two consecutive rare Arg codons (positions 98 and 99), led to the exclusive production of the more stable protein. Further analysis by LC/ESI-MS/MS showed that the 28 Da mass difference is due to the substitution of a Lys for an Arg residue at position 99. Overall, our work shows that two proteins with different biochemical and biophysical properties that coexist in the same cell environment are translated from the same nucleotide sequence frame
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