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Background: Reported data suggest that 4.2 million deaths will occur within 30 days of surgery worldwide each year, half of which are in low- and middle-income countries. Postoperative complications are a leading cause of long-term morbidity and mortality. Patients who survive and leave the hospital after surgical complications regularly experience reductions in long-term survival and functional independence, resulting in increased costs. With a high volume of surgery performed, there is a growing perception of the substantial impact of even minor enhancements in perioperative care. The Latin American Surgical Outcomes Study (LASOS) is an international, multicentre, prospective cohort study of adults submitted to in-patient surgery in Latin America aiming to provide detailed data describing postoperative complications and surgical mortality. Methods: LASOS is a 7 day cohort study of adults undergoing surgery in Latin America. Details of preoperative risk factors, intraoperative care, and postoperative outcomes will be collected. The primary outcome will be in-hospital postoperative complications of any cause. Secondary outcomes include in-hospital all-cause mortality, duration of hospital stay after surgery, and admission to a critical care unit within 30 days after surgery during the index hospitalisation. Results: The LASOS results will be published in peer-reviewed journals, reported and presented at international meetings, and widely disseminated to patients and public in participating countries via mainstream and social media. Conclusions: The LASOS may augment our understanding of postoperative complications and surgial mortality in Latin America. Clinical trial registration: NCT05169164.
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RESUMEN Desde 2015 a la fecha, los autores de esta revisión hemos implementado numerosos programas de optimización perioperatoria en Latinoamérica. En el siguiente artículo, presentamos una introducción general a los conceptos de optimización perioperatoria y resumimos nuestra experiencia trabajando en la región. También a lo largo de esta revisión, los lectores podrán encontrar desarrollados los tres elementos centrales de la optimización perioperatoria. En primer lugar, la constitución y los roles dentro un equipo perioperatorio. En segundo término, el registro sistemático y estandarizado de la práctica quirúrgica y sus resultados. Y, por último, la descripción del ciclo de mejoría continua como método de trabajo para ajustar la práctica diaria sobre la base del análisis de datos propios.
ABSTRACT From 2015 to date, the authors of this review have implemented several enhanced recovery periope rative programs in Latin America. In the following article, we present a general introduction to the con cepts of perioperative optimization and summarize our experience working in the region. Throughout this review, readers will also find the three fundamental elements of perioperative optimization. First, the creation and roles of a perioperative team. Second, the systematic and standardized registration of the surgical practice and its outcomes. And finally, the description of the continuous improvement cycle as a working method for adjusting daily practice based on the analysis of one's own data.
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RESUMEN Enhanced Recovery After Surgery (ERAS) constituye una forma de trabajo que implica la puesta en marcha de medidas de cuidado antes, durante y después de una cirugía con el propósito de mejorar la experiencia del paciente a lo largo del periodo perioperatorio. Sin embargo, la aplicación aislada de medidas determinadas no es suficiente. Esta forma de trabajo requiere la creación de un equipo de trabajo multidisciplinario, el registro sistemático de datos y su utilización para aplicar un ciclo de mejora continua. En el Hospital Italiano de Buenos Aires, se han registrado 1331 pacientes desde no viembre del año 2015. La mediana de internación fue de 4 días y la readmisión de 7,3%. La adherencia global a las medidas del programa fue del 56% (preoperatorio 88%, intraoperatorio 60%, postopera torio 39%). En los procedimientos quirúrgicos más frecuentes pudimos observar una relación lineal e inversamente proporcional entre adherencia al programa y el tiempo de internación, con una dismi nución promedio de un día de internación por cada 10% de adherencia al programa en los procedi mientos quirúrgicos más frecuentes. A pesar de estos resultados, hemos encontrado dificultades en el sistema de registro de datos que limitan la aplicación del ciclo de mejora continua. La conformación de un equipo multidisciplinario, con una comunicación fluida y eficiente es fundamental para la imple mentación de un programa ERAS® que sea capaz de disminuir el tiempo de internación, la morbilidad y el índice de readmisión.
ABSTRACT Enhanced Recovery After Surgery (ERAS) is a model of care that involves the implementation of care pathways before, during and after surgery designed to improve patient's experience throughout the perioperative period. Yet, the implementation of individual ERAS protocol elements is not sufficient. This approach requires the creation of a multidisciplinary work team, systematic recording of data and the use of the information recorded to implement a cycle of continuous improvement. Since 2015, 1331 patients have been recorded by Hospital Italiano de Buenos Aires. Median length of hospital stay was 4 days and median readmission rate was 7.3%. The overall adherence to the protocol elements was 56% (88% in the preoperative period, 60% in the intraoperative period and 39% in the postope rative period) There was a linear and inverse correlation between the adherence to the program and length of hospitalization for the most common surgical procedures, with an average decrease of one day of hospitalization for each 10% increase in adherence with the program for the most common sur gical procedures. Despite these results, we have encountered difficulties in the data recording systems limiting the implementation of the cycle of continuous improvement. The creation of a multidiscipli nary team, with fluent and efficient communication, is essential for the implementation of an ERAS® program capable of reducing length of hospital stay, morbidity and readmission rates.
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Los tumores de células germinales son una variante de los tumores ováricos, siendo el teratoma el más frecuente. Del total de los tumores ováricos diagnosticados, el 12% se encontrarán en pacientes en edad fértil. Se presenta el caso de una paciente de 22 años que acude a consulta con un diagnóstico presuntivo de teratoma bilateral en búsqueda de alternativas terapéuticas, ya que se le planteó originalmente ooforectomía bilateral. Tras un abordaje completo se corroboró el diagnóstico y se procedió a la resección tumoral, logrando la enucleación completa de ambos teratomas y preservando el tejido ovárico, su funcionalidad y su fertilidad.Germ cell tumors are a variant of ovarian tumors, with teratoma being the most frequent. Of the total number of diagnosed ovarian tumors, 12% are found in patients of childbearing age. In this case, we present a 22-year-old patient who comes to a consultation with a presumptive diagnosis of bilateral teratoma in search of therapeutic alternatives, since she was originally presented with a bilateral oophorectomy. After a complete approach, the diagnosis was corroborated and tumor resection was carried out, achieving complete enucleation of both teratomas, preserving the ovarian tissue, thus its functionality and fertility.
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Teratoma , Adulto , Feminino , Humanos , Estudos Retrospectivos , Teratoma/cirurgia , Adulto JovemRESUMO
Two-component systems (TCSs) in bacteria are molecular circuits that allow the perception of and response to diverse stimuli. These signaling circuits rely on phosphoryl-group transfers between transmitter and receiver domains of sensor kinase and response regulator proteins, and regulate several cellular processes in response to internal or external cues. Phosphorylation, and thereby activation, of response regulators has been demonstrated to occur by their cognate histidine kinases but also by low molecular weight phosphodonors such as acetyl phosphate and carbamoyl phosphate. Here, we present data indicating that the intermediates of the de novo syntheses of purines and histidine, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranosyl 5'-monophosphate (ZMP) and/or 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranosyl 5'-triphosphate (ZTP), activate the response regulator UvrY, by promoting its autophosphorylation at the conserved aspartate at position 54. Moreover, these Z nucleotides are shown to also activate the nonrelated response regulators ArcA, CpxR, RcsB, and PhoQ. We propose that ZMP and/or ZTP act as alarmones for a wide range of response regulators in vivo, providing a novel mechanism by which they could impact gene expression in response to metabolic cues.
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Escherichia coli/metabolismo , Nucleotídeos/farmacologia , Transdução de Sinais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos , Mutação/genética , Fosfatos/farmacologia , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
The shortage of hospital beds and changes in the payment model have promoted an increased attention and financing of programs that focus on perioperative care efficiency in. Latin America. In this paper, Enhanced Recovery After Surgery (ERAS) programs developed by the ERAS® Society will be discussed. The implementation and use of ERAS®Society Guidelines consistently demonstrated a reduction in postoperative complications, hospital stay and costs. In the current paper, the definition of ERAS programs, their core elements, and the results of their implementation and regional developments are presented with special focus on Latin America.
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Recuperação Pós-Cirúrgica Melhorada , Assistência Perioperatória , Humanos , América Latina , Tempo de Internação , Complicações Pós-OperatóriasRESUMO
The shortage of hospital beds and changes in the payment model have promoted an increased attention and financing of programs that focus on perioperative care efficiency in. Latin America. In this paper, Enhanced Recovery After Surgery (ERAS) programs developed by the ERAS® Society will be discussed. The implementation and use of ERAS®Society Guidelines consistently demonstrated a reduction in postoperative complications, hospital stay and costs. In the current paper, the definition of ERAS programs, their core elements, and the results of their implementation and regional developments are presented with special focus on Latin America.
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Humanos , Assistência Perioperatória , Recuperação Pós-Cirúrgica Melhorada , Complicações Pós-Operatórias , América Latina , Tempo de InternaçãoRESUMO
Introducción. Los protocolos de recuperación mejorada después de cirugía se han diseñado como una innovación en salud tras demostrarse que la mejora en los dispositivos médicos y la depuración de técnicas alcanzaron la meseta en disminución de complicaciones. Con estas estrategias de la medicina perioperatoria, en cirugía colorrectal se reducen la morbilidad y estancia hospitalaria. El objetivo del estudio fue evaluar si la tasa de adherencia al programa de recuperación mejorada después de la cirugía (ERAS) está asociada con los resultados quirúrgicos. Métodos. Estudio multicéntrico, observacional, retrospectivo de cohorte (2015-2019), en cinco hospitales latinoamericanos certificados por la sociedad ERAS. Se calculó la incidencia de complicaciones quirúrgicas durante el posquirúrgico inmediato (30 días) y la duración de la estancia hospitalaria. Se utilizaron análisis bivariado y regresión logística multivariada para evaluar los factores asociados con la tasa de complicaciones. Resultados. Fueron incluidos en el estudio 648 pacientes en cinco hospitales ERAS, con edad promedio de 61 años y mayor porcentaje de hombres (51 %). El cumplimiento global al protocolo ERAS fue de 75 % y la estancia promedio de 6,2 días (mediana: 4 días). Se tuvo un cumplimiento óptimo del protocolo ERAS (igual o mayor al 80 %) en 23,6 % de los pacientes. Se documentó fuga de la anastomosis en 4 %, complicaciones infecciosas en 8,4 %, íleo en 5,7 %, reingreso en 10,2 % y mortalidad de 1,1 %. El análisis multivariado mostró que los niveles de adherencia óptima al protocolo ERAS reducen significativamente la aparición de complicaciones como fuga de la anastomosis (OR 0,08; IC95% 0,01-0,48; p=0,005) y complicaciones infecciosas (OR 0,17; IC95%0,03-0,76; p=0,046).Discusión. Los resultados sugieren que un cumplimiento del programa ERAS mayor al 80 % se asocia a menor frecuencia de complicaciones en pacientes con cirugía electiva colorrectal
Introduction. Enhanced Recovery After Surgery (ERAS) protocol has been designed as an innovation in health after demonstrating that the improvement in medical devices and the refinement of techniques reached the plateau in reducing complications. With these strategies of perioperative medicine, in colorectal surgery morbidity and hospital stay are reduced. The aim of the study was to evaluate whether the rate of adherence to the ERAS protocol is associated with surgical outcomes.Methods. Multicenter, observational, retrospective cohort study (2015-2019), in five Latin American hospitals certified by the ERAS Society. The incidence of surgical complications during the immediate postoperative period (30 days) and length of hospital stay were calculated. Bivariate analyzes and multivariate logistic regression were used to assess factors associated with complication rates.Results. 648 patients were included in the study in five ERAS hospitals, with an average age of 61 years and a higher percentage of men (51%). Overall compliance with the ERAS protocol was 75% and the average stay was 6.2 days (median: 4 days). There was optimal compliance with the ERAS protocol (equal to or greater than 80%) in 23.6% of the patients. Anastomotic leak was documented in 4%, infectious complications in 8.4%, ileus in 5.7%, readmission in 10.2%, and mortality in 1.1%. Multivariate analysis showed that optimal adherence levels to the ERAS protocol significantly reduce the appearance of complications such as anastomotic leakage (OR 0.08; 95%CI 0.01-0.48; p=0.005) and infectious complications (OR 0.17; 95%CI 0.03-0.76; p=0.046).Discussion. The results suggest that compliance with the ERAS program greater than 80% is associated with a lower frequency of complications in patients with elective colorectal surgery
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Humanos , Recuperação Pós-Cirúrgica Melhorada , Doenças do Colo , Medidas de Associação, Exposição, Risco ou Desfecho , Cooperação e Adesão ao TratamentoRESUMO
The prevalence of obesity is increasing globally. Rational perioperative anesthetic drug selection and administration require knowledge of how obesity interacts with those drugs. In this review, we summarize different aspects of the anesthetic agents, including pharmacokinetics (PK), pharmacodynamics (PD) and clinical application of the most commonly used medications with particular focus on the enhanced recovery of the obese patient.
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Anestésicos/classificação , Cirurgia Bariátrica , Obesidade Mórbida/cirurgia , HumanosRESUMO
The Arc (anoxic redox control) two-component system of Escherichia coli, comprising ArcA as the response regulator and ArcB as the sensor histidine kinase, modulates the expression of numerous genes in response to respiratory growth conditions. Under reducing growth conditions, ArcB autophosphorylates at the expense of ATP, and transphosphorylates ArcA via a His292 â Asp576 â His717 â Asp54 phosphorelay, whereas under oxidizing growth conditions, ArcB catalyzes the dephosphorylation of ArcA-P by a reverse Asp54 â His717 â Asp576 â Pi phosphorelay. However, the exact phosphoryl group transfer routes and the molecular mechanisms determining their directions are unclear. Here, we show that, during signal propagation, the His292 â Asp576 and Asp576 â His717 phosphoryl group transfers within ArcB dimers occur intra- and intermolecularly, respectively. Moreover, we report that, during signal decay, the phosphoryl group transfer from His717 to Asp576 takes place intramolecularly. In conclusion, we present a mechanism that dictates the direction of the phosphoryl group transfer within ArcB dimers and that enables the discrimination of the kinase and phosphatase activities of ArcB.
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Ácido Aspártico/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Histidina/metabolismo , Proteínas de Membrana/metabolismo , Mutação , Proteínas Quinases/metabolismo , Ácido Aspártico/química , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Histidina/química , Proteínas de Membrana/química , Proteínas de Membrana/genética , Fosforilação , Proteínas Quinases/química , Proteínas Quinases/genética , Transdução de SinaisRESUMO
Lipid rafts or membrane microdomains have been proposed to compartmentalize cellular processes by spatially organizing diverse molecules/proteins in eukaryotic cells. Such membrane microdomains were recently reported to also exist in a few bacterial species. In this work, we report the development of a procedure for membrane microdomain isolation from Escherichia coli plasma membranes as well as a method to purify the latter. The method here reported could easily be adapted to other gram-negative bacteria, wherein the isolation of this kind of sub-membrane preparation imposes special difficulties. The analysis of isolated membrane microdomains might provide important information on the nature and function of these bacterial structures and permit their comparison with the ones of eukaryotic cells.
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Escherichia coli/química , Microdomínios da Membrana/química , Escherichia coli/metabolismo , Microdomínios da Membrana/metabolismoRESUMO
Objetiva-se com este trabalho discutir sobre o processo de expansão da educação superior no Brasil. Nesse sentido, procuramos revisar pontos determinantes e elementos caracterizadores do Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais (REUNI) refletindo sobre o acesso à universidade pública. Para isso realizamos uma breve discussão sobre Estado e políticas públicas, em especial as políticas para a educação superior, levando-se em consideração a relação estabelecida entre tais elementos e resgatando os determinantes desse movimento e suas particularidades. Buscamos analisar as políticas educacionais voltadas para a educação superior durante o governo Fernando Henrique Cardoso (FHC) e Lula, no que diz respeito ao acesso, bem como seus elementos norteadores. Essa contextualização leva em consideração, que a educação não pode ser considerada como fenômeno neutro e, portanto, decorre da intervenção do Estado, e os efeitos do espaço no qual está inserido. As análises indicam que o processo de reformas para a educação superior implementadas no Brasil, principalmente no âmbito do REUNI está impregnado de objetivos ideológicos, ações e contradições que se estabelecem em relação aos pressupostos teóricos e práticos, apresentando elementos que ao mesmo tempo resultam na reforma do Estado e buscam dar sustentação aos interesses sociais.
The objective of this work is to discuss the process of expansion of higher education in Brazil. In this sense, we seek to review determining points and elements that characterize the Federal University Restructuring and Expansion Program Support Program (REUNI), reflecting on access to the public university. In order to do so, we present a brief discussion about State and public policies, especially policies for higher education, taking into account the established relationship between these elements and rescuing the determinants of this movement and its particularities. We sought to analyze educational policies focused on higher education during the Fernando Henrique Cardoso (FHC) and Lula government, in terms of access, as well as its guiding elements. This contextualization takes into account, that education can not be considered as a neutral phenomenon and, therefore, stems from the intervention of the State, and the effects of the space in which it is inserted. The analysis indicates that the process of reforms for higher education implemented in Brazil, mainly within REUNI is impregnated with ideological objectives, actions and contradictions that are established in relation to theoretical and practical presuppositions, presenting elements that at the same time result in the reform Of the state and seek to support social interests.
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Humanos , Universidades , Política Pública , UniversidadesRESUMO
Objetiva-se com este trabalho discutir sobre o processo de expansão da educação superior no Brasil. Nesse sentido, procuramos revisar pontos determinantes e elementos caracterizadores do Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais (REUNI) refletindo sobre o acesso à universidade pública. Para isso realizamos uma breve discussão sobre Estado e políticas públicas, em especial as políticas para a educação superior, levando-se em consideração a relação estabelecida entre tais elementos e resgatando os determinantes desse movimento e suas particularidades. Buscamos analisar as políticas educacionais voltadas para a educação superior durante o governo Fernando Henrique Cardoso (FHC) e Lula, no que diz respeito ao acesso, bem como seus elementos norteadores. Essa contextualização leva em consideração, que a educação não pode ser considerada como fenômeno neutro e, portanto, decorre da intervenção do Estado, e os efeitos do espaço no qual está inserido. As análises indicam que o processo de reformas para a educação superior implementadas no Brasil, principalmente no âmbito do REUNI está impregnado de objetivos ideológicos, ações e contradições que se estabelecem em relação aos pressupostos teóricos e práticos, apresentando elementos que ao mesmo tempo resultam na reforma do Estado e buscam dar sustentação aos interesses sociais.(AU)
The objective of this work is to discuss the process of expansion of higher education in Brazil. In this sense, we seek to review determining points and elements that characterize the Federal University Restructuring and Expansion Program Support Program (REUNI), reflecting on access to the public university. In order to do so, we present a brief discussion about State and public policies, especially policies for higher education, taking into account the established relationship between these elements and rescuing the determinants of this movement and its particularities. We sought to analyze educational policies focused on higher education during the Fernando Henrique Cardoso (FHC) and Lula government, in terms of access, as well as its guiding elements. This contextualization takes into account, that education can not be considered as a neutral phenomenon and, therefore, stems from the intervention of the State, and the effects of the space in which it is inserted. The analysis indicates that the process of reforms for higher education implemented in Brazil, mainly within REUNI is impregnated with ideological objectives, actions and contradictions that are established in relation to theoretical and practical presuppositions, presenting elements that at the same time result in the reform Of the state and seek to support social interests.(AU)
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Humanos , Universidades , Universidades , Política PúblicaRESUMO
BACKGROUND: The present study aims to examine the feasibility and safety of a two-day hospital stay after laparoscopic colorectal resection (LCR) under an enhanced recovery after surgery (ERAS) pathway. METHODS: Between 2003 and 2010, 882 consecutive patients undergoing LCR were analyzed. Patients were grouped and analyzed according to whether their hospital stay was 2 days (group A) or longer (group B). Demographic, surgical, and postoperative data were compared. To identify independent predictive factors related to a short hospital stay, a multivariate analysis was also performed. RESULTS: Group A represented 10.3 % of this series (91 patients). There were no differences regarding age, gender, BMI, ASA, and previous abdominal surgeries between groups. Group A had a lower incidence of rectal cancer and anterior resections than group B (6.6 vs. 17.7 % [p = 0.006] and 14.3 vs. 23.4 % [p = 0.048]), respectively, and a lower mean operative time (170 min vs. 192 min; p = 0.002). Group A had a lower overall morbidity rate than group B (5.5 vs. 16.9 %; p = 0.004) and a lower incidence of surgery-related complications (5.5 vs. 14.9 %; p = 0.001). The overall conversion rate was 10 % (only one patient in group A required conversion), and the difference in conversion rate between groups was statistically significant (1.2 vs. 10.7 %; p = 0.003). Group A had a lower readmission rate (0 vs. 4.9 %; p = 0.089). Multivariate analysis showed that conversion, postoperative morbidity, and rectal prolapse were independently associated with the length of hospital stay. CONCLUSIONS: A two-day hospital stay after LCR is safe and feasible under an ERAS pathway, without compromising the readmission or complication rate.
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Colectomia/reabilitação , Doenças do Colo/cirurgia , Laparoscopia/reabilitação , Tempo de Internação/estatística & dados numéricos , Assistência Perioperatória/métodos , Doenças Retais/cirurgia , Reto/cirurgia , Idoso , Colectomia/métodos , Conversão para Cirurgia Aberta/estatística & dados numéricos , Procedimentos Clínicos , Técnicas de Apoio para a Decisão , Estudos de Viabilidade , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Análise Multivariada , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Análise de Regressão , Fatores de Risco , Resultado do TratamentoRESUMO
The Arc two-component system, comprising the ArcB sensor kinase and the ArcA response regulator, modulates the expression of numerous genes in response to respiratory growth conditions. Under aerobic growth conditions, the ubiquinone electron carriers were proposed to silence the kinase activity of ArcB by oxidizing two cytosol-located redox-active cysteine residues that participate in intermolecular disulfide bond formation. Here, we confirm the role of the ubiquinone electron carriers as the silencing signal of ArcB in vivo, we show that the redox potential of ArcB is about -41 mV, and we demonstrate that the menaquinols are required for proper ArcB activation upon a shift from aerobic to anaerobic growth conditions. Thus, an essential link in the Arc signal transduction pathway connecting the redox state of the quinone pool to the transcriptional apparatus is elucidated.
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Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Quinases/metabolismo , Ubiquinona/metabolismo , Vitamina K 2/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Membrana/genética , Oxirredução , Proteínas Quinases/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologiaRESUMO
The Arc (anoxic redox control) two-component system (TCS) is a complex signal transduction system that plays an important role in regulating energy metabolism at the level of transcription in bacteria. This system comprises the ArcB protein, a hybrid membrane-associated sensor kinase, and the ArcA protein, a typical response regulator. Under anoxic growth conditions, ArcB autophosphorylates and transphosphorylates ArcA via a HisâAspâHisâAsp phosphorelay. Under aerobic conditions, the ArcB kinase activity is silenced by the oxidation of two cytosol-located redox-active cysteine residues that participate in intermolecular disulfide bond formation. Under such conditions, ArcB acts as a phosphatase that catalyzes the dephosphorylation of ArcA-P and thereby releasing its transcriptional regulation. This chapter describes general in vitro and in vivo assays and strategies that have been used to characterize the ArcB/A two-component signal transduction system, which could, also, be applied to most other TCS.
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Proteínas de Bactérias/metabolismo , Proteínas Quinases/metabolismo , Transdução de Sinais/fisiologia , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Oxirredução , Fosforilação , Proteínas Quinases/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais/genéticaRESUMO
The two-component signal transduction system (TCS) BarA/UvrY activates transcription of CsrB and CsrC noncoding RNAs, which act by sequestering the RNA-binding global regulatory protein CsrA. Here, we show that the metabolic end products formate and acetate provide a physiological stimulus for this TCS and thus link posttranscriptional regulation by the Csr system to the metabolic state of the cell.
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Proteínas de Escherichia coli/fisiologia , Escherichia coli/fisiologia , Regulação Bacteriana da Expressão Gênica , Proteínas de Membrana/fisiologia , Fosfotransferases/fisiologia , Transdução de Sinais , Ácido Acético/metabolismo , Formiatos/metabolismoRESUMO
The Arc (anoxic redox control) two-component signal transduction system, consisting of the ArcB sensor kinase and the ArcA response regulator, allows adaptive responses of Escherichia coli to changes of O(2) availability. The arcA gene was previously known as the dye gene because null mutants were growth sensitive to the photosensitizer redox dyes toluidine blue and methylene blue, a phenotype whose molecular basis still remains elusive. In this study we report that the toluidine blue O (TBO) effect on the arc mutants is light independent and observed only during aerobic growth conditions. Moreover, 16 suppressor mutants with restored growth were generated and analyzed. Thirteen of those possessed insertion elements upstream of the cydAB operon, rendering its expression ArcA independent. Also, it was found that, in contrast to cythocrome d, cythocrome o was not able to confer toluidine blue resistance to arc mutants, thereby representing an intriguing difference between the two terminal oxidases. Finally, a mechanism for TBO sensitivity and resistance is discussed.
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Proteínas da Membrana Bacteriana Externa/genética , Grupo dos Citocromos b/metabolismo , Grupo dos Citocromos d/metabolismo , Citocromos/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Proteínas Repressoras/genética , Cloreto de Tolônio/farmacologia , Anaerobiose , Proteínas da Membrana Bacteriana Externa/metabolismo , Sequência de Bases , Carotenoides/metabolismo , Catalase/metabolismo , Corantes/farmacologia , Grupo dos Citocromos b/genética , Grupo dos Citocromos d/genética , Citocromos/genética , Escuridão , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/genética , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Glucose/farmacologia , Luz , Dados de Sequência Molecular , Mutação/genética , Oxirredutases/genética , Regiões Promotoras Genéticas/genética , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/metabolismo , Homologia de Sequência do Ácido Nucleico , Superóxido Dismutase/metabolismoRESUMO
BACKGROUND: Members of the genus Rhodococcus are frequently found in soil and other natural environments and are highly resistant to stresses common in those environments. The accumulation of storage compounds permits cells to survive and metabolically adapt during fluctuating environmental conditions. The purpose of this study was to perform a genome-wide bioinformatic analysis of key genes encoding metabolism of diverse storage compounds by Rhodococcus jostii RHA1 and to examine its ability to synthesize and accumulate triacylglycerols (TAG), wax esters, polyhydroxyalkanoates (PHA), glycogen and polyphosphate (PolyP). RESULTS: We identified in the RHA1 genome: 14 genes encoding putative wax ester synthase/acyl-CoA:diacylglycerol acyltransferase enzymes (WS/DGATs) likely involved in TAG and wax esters biosynthesis; a total of 54 genes coding for putative lipase/esterase enzymes possibly involved in TAG and wax ester degradation; 3 sets of genes encoding PHA synthases and PHA depolymerases; 6 genes encoding key enzymes for glycogen metabolism, one gene coding for a putative polyphosphate kinase and 3 putative exopolyphosphatase genes. Where possible, key amino acid residues in the above proteins (generally in active sites, effectors binding sites or substrate binding sites) were identified in order to support gene identification. RHA1 cells grown under N-limiting conditions, accumulated TAG as the main storage compounds plus wax esters, PHA (with 3-hydroxybutyrate and 3-hydroxyvalerate monomers), glycogen and PolyP. Rhodococcus members were previously known to accumulate TAG, wax esters, PHAs and polyP, but this is the first report of glycogen accumulation in this genus. CONCLUSION: RHA1 possess key genes to accumulate diverse storage compounds. Under nitrogen-limiting conditions lipids are the principal storage compounds. An extensive capacity to synthesize and metabolize storage compounds appears to contribute versatility to RHA1 in its responses to environmental stresses.