Importance of Bacillithiol in the Oxidative Stress Response of Staphylococcus aureus

In Staphylococcus aureus, the low-molecular-weight thiol called bacillithiol (BSH), together with cognate S-transferases, is believed to be the counterpart to the glutathione system of other organisms. To explore the physiological role of BSH in S. aureus, we constructed mutants with the deletion of bshA (sa1291), which encodes the glycosyltransferase that catalyzes the first step of BSH biosynthesis, and fosB (sa2124), which encodes a BSH-S-transferase that confers fosfomycin resistance, in several S. aureus strains, including clinical isolates. Mutation of fosB or bshA caused a 16- to 60-fold reduction in fosfomycin resistance in these S. aureus strains. High-pressure liquid chromatography analysis, which quantified thiol extracts, revealed some variability in the amounts of BSH present across S. aureus strains. Deletion of fosB led to a decrease in BSH levels. The fosB and bshA mutants of strain COL and a USA300 isolate, upon further characterization, were found to be sensitive to H2O2 and exhibited decreased NADPH levels compared with those in the isogenic parents. Microarray analyses of COL and the isogenic bshA mutant revealed increased expression of genes involved in staphyloxanthin synthesis in the bshA mutant relative to that in COL under thiol stress conditions. However, the bshA mutant of COL demonstrated decreased survival compared to that of the parent in human whole-blood survival assays; likewise, the naturally BSH-deficient strain SH1000 survived less well than its BSH-producing isogenic counterpart. Thus, the survival of S. aureus under oxidative stress is facilitated by BSH, possibly via a FosB-mediated mechanism, independently of its capability to produce staphyloxanthin

Comparación de métodos para la determinación del valor energético de alimentos para rumiantes

RESUMEN Objetivo. Comparar métodos de estimación del TND a partir de ensayos de digestibilidad y análisis químico de la dieta. Materiales y métodos. La digestibilidad in vivo fue determinada usando cebuínos alimentados con heno (Cynodon dactylon L. Pers. cv. Tifton 85), maíz y soya. La digestibilidad in vitro siguió la metodología de Tilley y Terry (TT). Los métodos de estimación del TND fueron: convencional (MET 1), calorimétrico desde valores de combustión cuantificados en bomba calorimétrica (MET 2), calorimétrico desde calores de combustión predefinidos (MET 3), desde la digestibilidad in vivo e in vitro de la materia orgánica (MET 4), desde el modelo multicompartimental del NRC (2001) (MET 5). Los datos se analizaron en diseño completamente aleatorizado y la comparación del efecto promedio se realizó usando la prueba de Tukey (α=5%). La intercambiabilidad entre los valores de TND obtenidos desde el procedimiento TT (MET 4) y el MET 5 se valoró a partir del método de Bland-Altman. Resultados. Los valores de TND estimados in vivo por MET 1, MET 3 y MET 4 no presentaron diferencia (p>0.05) pero difirieron del valor obtenido por MET 2 (p<0.05), que fue menor. Los valores de TND del MET 5 no fueron intercambiables con los obtenidos desde el procedimiento TT, que superaron los rangos encontrados en la literatura. Conclusiones. La estimación del TND desde MET 2 es más confiable porque no se hacen presunciones u omisiones en el valor energético de los componentes orgánicos. El MET 5 se mostró promisorio para el cálculo del TND

Estimación de parámetros de curvas de crecimiento de ganado Nellore criado en confinamiento

RESUMEN Objetivo. Comparar los modelos de regresión no lineal Brody, Gompertz, Logístico y vonBertalanffy, e identificar cual de ellos describe mejor el crecimiento de machos enteros Nellorecriados en régimen de confinamiento, recibiendo suplementación alimenticia y sometidosa manejo experimental. Materiales y métodos. La estimativa de los parámetros de cadamodelo se realizó a través del procedimiento para modelos no lineales PROC NLIN de SAS,a partir de datos de peso colectados desde los 352 hasta los 833 días de edad. Resultados.El cuadrado medio del error, el coeficiente de determinación y la dócima de Durbin-Watsonpermitieron concluir que todas las funciones presentaron comportamiento similar en sucapacidad de ajuste; no obstante, el análisis de normalidad de residuos demostró que elmodelo logístico no cumplió con este supuesto (p0.05) permitióasegurar que la inferencia sobre los parámetros fue adecuada, con independencia delos cambios de peso resultantes de la aplicación de diversos planos alimenticios. Por lainterpretación biológica de los parámetros, el modelo Brody fue el que presentó la mejordescripción del crecimiento de machos Nellore. Los mayores pesos maduros y las menorestasas de madurez obtenidas en este trabajo, en relación con los reportes de la literatura,indica que los animales alcanzarían peso asintótico en edad más avanzada en razón de sudesarrollo más lento, consecuencia del manejo experimental al que fueron sometidos

Comparación de métodos para la determinación del valor energético de alimentos para rumiantes

RESUMENObjetivo. Comparar métodos de estimación del TND a partir de ensayos de digestibilidad y análisis químico de la dieta. Materiales y métodos. La digestibilidad in vivo fue determinada usando cebuínos alimentados con heno (Cynodon dactylon L. Pers. cv. Tifton 85), maíz y soya. La digestibilidad in vitro siguió la metodología de Tilley y Terry (TT). Los métodos de estimación del TND fueron: convencional (MET 1), calorimétrico desde valores de combustión cuantificados en bomba calorimétrica (MET 2), calorimétrico desde calores de combustión predefinidos (MET 3), desde la digestibilidad in vivo e in vitro de la materia orgánica (MET 4), desde el modelo multicompartimental del NRC (2001) (MET 5). Los datos se analizaron en diseño completamente aleatorizado y la comparación del efecto promedio se realizó usando la prueba de Tukey (α=5%). La intercambiabilidad entre los valores de TND obtenidos desde el procedimiento TT (MET 4) y el MET 5 se valoró a partir del método de Bland-Altman. Resultados. Los valores de TND estimados in vivo por MET 1, MET 3 y MET 4 no presentaron diferencia (p&gt;0.05) pero difirieron del valor obtenido por MET 2 (p&lt;0.05), que fue menor. Los valores de TND del MET 5 no fueron intercambiables con los obtenidos desde el procedimiento TT, que superaron los rangos encontrados en la literatura. Conclusiones. La estimación del TND desde MET 2 es más confiable porque no se hacen presunciones u omisiones en el valor energético de los componentes orgánicos. El MET 5 se mostró promisorio para el cálculo del TND

The role of backstop shape during inversion tectonics physical models.

O estilo da deforma??o de sequ?ncias sedimentares de bacias submetidas a uma invers?o tect?nica positiva foi discutido a partir da an?lise de modelos laboratoriais, desenvolvidos em caixas de experimentos, com camadas de areia depositadas no espa?o entre dois blocos de madeira. O espa?o simulava est?gios de extens?o crustal que conduziram ? forma??o de (1) um hemi-graben, gerado sobre um descolamento basal l?strico, com os blocos simulando o teto e o muro; e (2) um graben, com os blocos representando as margens externas que se distanciaram ao longo de um descolamento horizontal. Combina??es de dois angulos diferentes foram usadas para simular o mergulho das falhas normais curvas ao longo da face interna dos blocos de madeira. Nos hemi-grabens, os anteparos possu?am geometria convexa, e, nos grabens, geometria c?ncava. No pacote de areia, o encurtamento foi particionado em movimentos dirigidos a p?s e antepa?s, e a cinem?tica da contra??o foi fortemente influenciada pela geometria convexa ou c?ncava das faces internas dos anteparos. Um efeito obst?culo, caracterizado por rota??o do pacote de areia, pr?ximo ao bloco do muro, foi mais elevado junto ?s faces internas dos blocos de mais alto angulo de mergulho. Os resultados foram comparados a outros experimentos f?sicos e aplicados a uma bacia invertida encontrada na natureza.The style of deformation of rocks from basin-infilling sequences in positively inverted natural basins was discussed upon the results of laboratory experiments carried out in sandboxes with sand packs laid down in the space between two wooden blocks. The space simulated stages of crustal extension leading to (1) a half graben due to extension above a listric extensional detachment, with the blocks simulating the footwall and hanging wall, or (2) a graben, with the blocks simulating the external margins that drifted apart above a horizontal detachment. Combinations of two diferente angles were used to simulate the dip of curved normal faults along the internal face of the wooden blocks. Backstops in the half graben had a convex up internal face. Backstops in the graben had a concave up internal face. Shortening was partitioned in forward and backward movements within the sand packs, and the kinematics of contraction was largely influenced by the convex or concave internal faces. A buttress effect characterized by rotation of the sand pack close to the footwall was stronger for footwall with steeper-dipping internal faces. The results were compared to other physical experiments and applied to an inverted basin found in nature

Short-term follow-up of chagasic patients after benznidazole treatment using multiple serological markers

<p>Abstract</p> <p>Background</p> <p>Conventional serological tests, using total soluble proteins or a cocktail of recombinant proteins from <it>T. cruzi </it>as antigens, are highly sensitive for Chagas disease diagnosis. This type of tests, however, does not seem to be reliable tools for short- and medium-term monitoring of the evolution of patients after antiparasitic treatment. The aim of the present study was to search for immunological markers that could be altered in the sera from Chagas disease patients after benznidazole treatment, and therefore have a potential predictive diagnostic value.</p> <p>Methods</p> <p>We analyzed the reactivity of sera from chagasic patients during different clinical phases of the disease against a series of immunodominant antigens, known as KMP11, PFR2, HSP70 and Tgp63. The reactivity of the sera from 46 adult Chronic Chagas disease patients living in a non-endemic country without vector transmission of <it>T. cruzi </it>(15 patients in the indeterminate stage, 16 in the cardiomiopathy stage and 16 in the digestive stage) and 22 control sera from non-infected subjects was analyzed. We also analyzed the response dynamics of sera from those patients who had been treated with benznidazole.</p> <p>Results</p> <p>Regardless of the stage of the sickness, the sera from chagasic patients reacted against KMP11, HSP70, PFR2 and Tgp63 recombinant proteins with statistical significance relative to the reactivity against the same antigens by the sera from healthy donors, patients with autoimmune diseases or patients suffering from tuberculosis, leprosy or malaria. Shortly after benznidazole treatment, a statistically significant decrease in reactivity against KMP11, HSP70 and PFR2 was observed (six or nine month). It was also observed that, following benznidazole treatment, the differential reactivity against these antigens co-relates with the clinical status of the patients.</p> <p>Conclusions</p> <p>The recombinant antigens KMP11, PFR2, Tgp63 and HSP70 are recognized by Chagas disease patients' sera at any clinical stage of the disease. Shortly after benznidazole treatment, a drop in reactivity against three of these antigens is produced in an antigen-specific manner. Most likely, analysis of the reactivity against these recombinant antigens may be useful for monitoring the effectiveness of benznidazole treatment.</p

Countries Response for People With Disabilities During the COVID-19 Pandemic

Background and ObjectivesDuring the Coronavirus disease 19 (COVID-19) pandemic, isolation and prevention measures to reduce COVID-19 contagions are essential for the care of all people; these measures should comply with the principles of inclusion and accessibility for people with disabilities (PWD), with all kinds of deficiencies and levels of dependency. Thereby, the aim of this article is to present the measures adopted for PWD or people with rehabilitation needs, for containment, mitigation, or suppression of the SARS-CoV-2 virus in different countries of all continents and of all income levels.MethodsA narrative approach was used in this article. First, a broad search was carried out in the 193 member states of the UN, and then 98 countries that issued any document, report, or information related to disability and COVID-19 were selected. Finally, 32 countries were included in this article because they presented official information. We considered official sources, the information available in the government, or on the health ministry page of the country. In this way, the countries that presented information which did not correspond to an official source were excluded. The search was conducted in August 2020 and updated in March 2021.ResultsFirst, the non-pharmacological general interventions for PWD included informative measures and general recommendations during the stay at home, isolation, and biosecurity measures, contagion prevention, detection of positive cases, mobilization measures, and measures implemented in institutions or residences of PWD. Second, we identified the economic and social benefits provided to PWD during the pandemic. Finally, we identified the measures taken by countries according to the type of impairment (visual, hearing, physical, mental, and cardiopulmonary impairment) during the COVID-19 pandemic.ConclusionIn response to the COVID-19 pandemic, only 50% of countries from the five world regions created and implemented specific measures for PWD to containment, mitigation, or suppression of the SARS-CoV-2 virus. There is very little specific information available about the measures to continue with the care of people with rehabilitation needs and the long-term follow-up of PWD, and for the prevention and response to violence, especially for women with disabilities

Characterization of Dengue Virus Type 2: New Insights on the 2010 Brazilian Epidemic

Dengue viruses (DENV) serotypes 1, 2, and 3 have been causing yearly outbreaks in Brazil. In this study, we report the re-introduction of DENV2 in the coast of São Paulo State. Partial envelope viral genes were sequenced from eighteen patients with dengue fever during the 2010 epidemic. Phylogenetic analysis showed this strain belongs to the American/Asian genotype and was closely related to the virus that circulated in Rio de Janeiro in 2007 and 2008. The phylogeny also showed no clustering by clinical presentation, suggesting that the disease severity could not be explained by distinct variants or genotypes. The time of the most recent common ancestor of American/Asian genotype and the São Paulo and Rio de Janeiro (SP/RJ) monophyletic cluster was estimated to be around 40 and 10 years, respectively. Since this virus was first identified in Brazil in 2007, we suggest that it was already circulating in the country before causing the first documented outbreak. This is the first description of the 2010 outbreak in the State of São Paulo, Brazil, and should contribute to efforts to control and monitor the spread of DENVs in endemic areas

Chagas Cardiomiopathy: The Potential of Diastolic Dysfunction and Brain Natriuretic Peptide in the Early Identification of Cardiac Damage

Chagas disease remains a major cause of morbidity and mortality in several countries of Latin America and has become a potential public health problem in countries where the disease is not endemic as a result of migration flows. Cardiac involvement represents the main cause of mortality, but its diagnosis is still based on nonspecific criteria with poor sensitivity. Early identification of patients with cardiac damage is desirable, since early treatment may improve prognosis. Diastolic dysfunction and elevated brain natriuretic peptide levels are present in different cardiomyopathies and in advanced phases of Chagas disease. However, there are scarce data about the role of these parameters in earlier forms of the disease. We conducted a study to assess the diastolic function, regional systolic abnormalities and brain natriuretic peptide levels in the different forms of Chagas disease. The main finding of our investigation is that diastolic dysfunction occurs before any cardiac dilatation or motion abnormality. In addition, BNP levels identify patients with diastolic dysfunction and Chagas disease with high specificity. The results reported in this study could help to early diagnose myocardial involvement and better stratify patients with Chagas disease