RESUMEN
Polychlorinated biphenyls (PCBs) are persistent organic pollutants with severe effects on human health and the biosphere. Plant-based remediation offers many benefits over conventional PCB remediation, but its development has been hampered by our poor understanding of biphenyl metabolism in eukaryotes, among other factors. We report here a major PCB-responsive protein in poplar, a plant model system capable of PCB uptake and translocation. We provide structural and functional evidence that this uncharacterized protein, termed SDR57C, belongs to the heterogeneous short-chain dehydrogenase reductase (SDR) superfamily. Despite sequence divergence, structural modeling hinted at structural and functional similarities between SDR57C and BphB, a central component of the Bph pathway for biphenyl/PCB degradation in aerobic bacteria. By combining gas chromatography/mass spectrometry (GC/MS) profiling with a functional complementation scheme, we found that poplar SDR57C can replace BphB activity in the upper Bph pathway of Pseudomonas furukawaii KF707 and therefore catalyze the oxidation of 2,3-dihydro-2,3-dihydroxybiphenyl (2,3-DHDB) to 2,3-dihydroxybiphenyl (2,3-DHB). Consistent with this biochemical activity, we propose a mechanism of action based on prior quantum studies, general properties of SDR enzymes, and the modeled docking of 2,3-DHDB to the SDR57C-NAD+ complex. The putative detoxifying capacity of SDR57C was substantiated through reverse genetics in Arabidopsis thaliana Phenotypic characterization of the SDR lines underscored an inducible plant pathway with the potential to catabolize toxic biphenyl derivatives. Partial similarities with aerobic bacterial degradation notwithstanding, real-time messenger RNA quantification indicates the occurrence of plant-specific enzymes and features. Our results may help explain differences in degradative abilities among plant genotypes and also provide elements to improve them.
Asunto(s)
Arabidopsis/efectos de los fármacos , Biodegradación Ambiental , Proteínas de Plantas/metabolismo , Bifenilos Policlorados/metabolismo , Populus/enzimología , Pseudomonas/fisiología , Deshidrogenasas-Reductasas de Cadena Corta/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/microbiología , Proteínas de Plantas/genética , Deshidrogenasas-Reductasas de Cadena Corta/genéticaRESUMEN
Infection (either community acquired or nosocomial) is a major cause of morbidity and mortality in critical care medicine. Sepsis is present in up to 30% of all ICU patients. A large fraction of sepsis cases is driven by severe community acquired pneumonia (sCAP), which incidence has dramatically increased during COVID-19 pandemics. A frequent complication of ICU patients is ventilator associated pneumonia (VAP), which affects 10-25% of all ventilated patients, and bloodstream infections (BSIs), affecting about 10% of patients. Management of these severe infections poses several challenges, including early diagnosis, severity stratification, prognosis assessment or treatment guidance. Digital PCR (dPCR) is a next-generation PCR method that offers a number of technical advantages to face these challenges: it is less affected than real time PCR by the presence of PCR inhibitors leading to higher sensitivity. In addition, dPCR offers high reproducibility, and provides absolute quantification without the need for a standard curve. In this article we reviewed the existing evidence on the applications of dPCR to the management of infection in critical care medicine. We included thirty-two articles involving critically ill patients. Twenty-three articles focused on the amplification of microbial genes: (1) four articles approached bacterial identification in blood or plasma; (2) one article used dPCR for fungal identification in blood; (3) another article focused on bacterial and fungal identification in other clinical samples; (4) three articles used dPCR for viral identification; (5) twelve articles quantified microbial burden by dPCR to assess severity, prognosis and treatment guidance; (6) two articles used dPCR to determine microbial ecology in ICU patients. The remaining nine articles used dPCR to profile host responses to infection, two of them for severity stratification in sepsis, four focused to improve diagnosis of this disease, one for detecting sCAP, one for detecting VAP, and finally one aimed to predict progression of COVID-19. This review evidences the potential of dPCR as a useful tool that could contribute to improve the detection and clinical management of infection in critical care medicine.
Asunto(s)
COVID-19 , COVID-19/diagnóstico , Cuidados Críticos , Humanos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: The objective of this study was to evaluate the virulence of P. aeruginosa ventilator-associated pneumonia (VAP) strains (cases) in terms of biofilm production and other phenotypic and genotypic virulence factors compared to P. aeruginosa strains isolated from other infections (controls). METHODS: Biofilm production was tested to assess biomass production and metabolic activity using crystal violet binding assay and XTT assay, respectively. Pigment production (pyocyanin and pyoverdine) was evaluated using cetrimide agar. Virulence genes were detected by conventional multiplex PCR and virulence was tested in an in vivo model in Galleria mellonella larvae. RESULTS: We did not find statistically significant differences between VAP and no-VAP strains (p > 0.05) regarding biofilm production. VAP strains had no production of pyocyanin after 24 h of incubation (p = 0.023). The distribution of virulence genes between both groups were similar (p > 0.05). VAP strains were less virulent than non-VAP strains in an in vivo model of G. mellonella (p < 0.001). CONCLUSION: The virulence of VAP-Pseudomonas aeruginosa does not depend on biofilm formation, production of pyoverdine or the presence of some virulence genes compared to P. aeruginosa isolated from non-invasive locations. However, VAP strains showed attenuated virulence compared to non-VAP strains in an in vivo model of G. mellonella.
Asunto(s)
Neumonía Asociada al Ventilador/microbiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/patogenicidad , Biopelículas , Genotipo , Humanos , Reacción en Cadena de la Polimerasa Multiplex , Oligopéptidos/metabolismo , Fenotipo , Pseudomonas aeruginosa/metabolismo , Piocianina/metabolismo , Ventiladores Mecánicos/efectos adversos , Virulencia/genética , Factores de Virulencia/genéticaRESUMEN
Background: The ST131 Escherichia coli clone is associated with the global dissemination of ESBLs. It has been hypothesized that ST131 could take advantage of better colonizing abilities. However, the data on colonization prevalence of ESBL-ST131 in European hospitals are scarce. Objectives: To assess the prevalence of the ST131 clone and its microbiological characteristics among colonizing ESBL-producing E. coli (ESBL-Ec) from hospitalized patients in four European hospitals (Berlin, Geneva, Madrid and Utrecht) during the R-GNOSIS study. Methods: ESBL-Ec isolates (n = 688) were obtained from rectal swabs of hospitalized patients from March 2014 to February 2015 using selective media. The ST131 clone and its subclones were sought using PCR and positive isolates were further studied. blaESBL genes were characterized (PCR and sequencing), antibiotic susceptibility testing was performed, clonal relationships were studied by PFGE and fimH allele and O type (PCR) were assessed. Results: ST131 prevalence was 20.5% (141/688); C1/H30R1 isolates were significantly more prevalent in Geneva (49%) and C2/H30Rx in Madrid (67%). C1/H30R1 isolates showed less resistance to amikacin than C2/H30Rx (4% versus 35%) and all were susceptible to penicillin/inhibitor combinations. CTX-M-15 was the most common enzyme (49%) followed by CTX-M-27 (27%). C1/H30R1 isolates were significantly associated with CTX-M-27 (72%) and all of these isolates belonged to the C1-M27 clade. Moreover, C2/H30Rx isolates and CTX-M-15 were also significantly related (88%). Conclusions: The predominance of C2/H30Rx-CTX-M-15 in Madrid and C1/H30R1-CTX-M-27 in Geneva demonstrates a changing epidemiology of ESBLs in Europe caused by ST131 subclones; in particular, the emergence of the C1-M27 clade in Europe.
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Antibacterianos/farmacología , Infecciones por Escherichia coli/epidemiología , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , beta-Lactamasas/genética , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Escherichia coli/enzimología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Europa (Continente)/epidemiología , Genotipo , Hospitalización/estadística & datos numéricos , Humanos , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , PrevalenciaRESUMEN
Modification of proteins by SUMO is essential for the maintenance of genome integrity. During DNA replication, the Mms21-branch of the SUMO pathway counteracts recombination intermediates at damaged replication forks, thus facilitating sister chromatid disjunction. The Mms21 SUMO ligase docks to the arm region of the Smc5 protein in the Smc5/6 complex; together, they cooperate during recombinational DNA repair. Yet how the activity of the SUMO ligase is controlled remains unknown. Here we show that the SUMO ligase and the chromosome disjunction functions of Mms21 depend on its docking to an intact and active Smc5/6 complex, indicating that the Smc5/6-Mms21 complex operates as a large SUMO ligase in vivo. In spite of the physical distance separating the E3 and the nucleotide-binding domains in Smc5/6, Mms21-dependent sumoylation requires binding of ATP to Smc5, a step that is part of the ligase mechanism that assists Ubc9 function. The communication is enabled by the presence of a conserved disruption in the coiled coil domain of Smc5, pointing to potential conformational changes for SUMO ligase activation. In accordance, scanning force microscopy of the Smc5-Mms21 heterodimer shows that the molecule is physically remodeled in an ATP-dependent manner. Our results demonstrate that the ATP-binding activity of the Smc5/6 complex is coordinated with its SUMO ligase, through the coiled coil domain of Smc5 and the physical remodeling of the molecule, to promote sumoylation and chromosome disjunction during DNA repair.
Asunto(s)
Proteínas de Ciclo Celular/genética , ADN de Hongos/metabolismo , Regulación Fúngica de la Expresión Génica , Reparación del ADN por Recombinación , Proteína SUMO-1/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Adenosina Trifosfato/metabolismo , Sitios de Unión , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Cromátides/metabolismo , Cromátides/ultraestructura , Daño del ADN , Replicación del ADN , ADN de Hongos/química , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Proteína SUMO-1/química , Proteína SUMO-1/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Transducción de Señal , Sumoilación , Enzimas Ubiquitina-Conjugadoras/genética , Enzimas Ubiquitina-Conjugadoras/metabolismoRESUMEN
BACKGROUND: Characterization of the expression and function of genes regulating embryo development in conifers is interesting from an evolutionary point of view. However, our knowledge about the regulation of embryo development in conifers is limited. During early embryo development in Pinus species the proembyo goes through a cleavage process, named cleavage polyembryony, giving rise to four embryos. One of these embryos develops to a dominant embryo, which will develop further into a mature, cotyledonary embryo, while the other embryos, the subordinate embryos, are degraded. The main goal of this study has been to identify processes that might be important for regulating the cleavage process and for the development of a dominant embryo. RESULTS: RNA samples from embryos and megagametophytes at four early developmental stages during seed development in Pinus sylvestris were subjected to high-throughput sequencing. A total of 6.6 million raw reads was generated, resulting in 121,938 transcripts, out of which 36.106 contained ORFs. 18,638 transcripts were differentially expressed (DETs) in embryos and megagametophytes. GO enrichment analysis of transcripts up-regulated in embryos showed enrichment for different cellular processes, while those up-regulated in megagametophytes were enriched for accumulation of storage material and responses to stress. The highest number of DETs was detected during the initiation of the cleavage process. Transcripts related to embryogenic competence, cell wall modifications, cell division pattern, axis specification and response to hormones and stress were highly abundant and differentially expressed during early embryo development. The abundance of representative DETs was confirmed by qRT-PCR analyses. CONCLUSION: Based on the processes identified in the GO enrichment analyses and the expression of the selected transcripts we suggest that (i) processes related to embryogenic competence and cell wall loosening are involved in activating the cleavage process; (ii) apical-basal polarization is strictly regulated in dominant embryos but not in the subordinate embryos; (iii) the transition from the morphogenic phase to the maturation phase is not completed in subordinate embryos. This is the first genome-wide transcript expression profiling of the earliest stages during embryo development in a Pinus species. Our results can serve as a framework for future studies to reveal the functions of identified genes.
Asunto(s)
Pinus sylvestris/genética , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica/genética , Regulación de la Expresión Génica de las Plantas/genética , Pinus sylvestris/embriología , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
OBJECTIVES: The objective of this study was to assess the prevalence and molecular epidemiology of ESBL-producing Escherichia coli causing healthcare-associated (HCA) and community-associated (CA) bacteraemia of urinary origin (BUO) in Spain. METHODS: An observational cohort study was conducted at eight hospitals from different Spanish geographical areas (2010-11). BUO episodes (nâ=â425) were classified as HCA (nâ=â215) and CA (nâ=â210), and one blood isolate per episode was collected. Susceptibility testing was performed, ESBLs were screened by double-disc diffusion test and ESBL and OXA-1 genes were characterized (PCR and sequencing). Population structure (phylogenetic groups, XbaI-PFGE and MLST) and ST131 subtyping (PCR) were determined. Virulence genes were detected by PCR and virulence score, profiles and extraintestinal pathogenic E. coli (ExPEC) status calculated. RESULTS: ESBL-producing E. coli prevalence was 9.2% (39/425). ESBL-producing E. coli episodes were significantly associated with HCA-BUO episodes [14% (30/215) versus 4.3% (9/210); Pâ=â0.001]. The highest non-susceptibility proportions corresponded to ciprofloxacin (97.4%), amoxicillin/clavulanate (74.4%), co-trimoxazole (69.2%) and tobramycin (61.5%). Of the 39 ESBL-producing E. coli isolates, 34 produced CTX-M enzymes (21 CTX-M-15, 11 CTX-M-14 and 2 CTX-M-1). Fifteen STs were identified, the B2-ST131 clone being the most prevalent (54%; 21/39). All ST131 isolates were ExPEC and had the highest virulence scores, but they showed less diversity in virulence profiles than other STs. The H30Rx subclone accounted for most ST131 isolates (20/21), co-produced CTX-M-15 (20/20) and OXA-1 (19/20) enzymes and was associated with HCA episodes (16/20). CONCLUSIONS: The CTX-M-15-ST131-H30Rx subclone is a relevant MDR pathogen causing BUO, mainly HCA episodes. The dominance of this subclone with comparatively less diversity of virulence profiles reflects the spread of a successful and MDR ESBL ST131 lineage in Spain.
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Bacteriemia/epidemiología , Bacteriemia/microbiología , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/clasificación , Genotipo , Infecciones Urinarias/complicaciones , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/clasificación , Infecciones por Escherichia coli/genética , Femenino , Hospitales , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Epidemiología Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN , España/epidemiología , Factores de Virulencia/genética , beta-Lactamasas/genéticaRESUMEN
Climate-driven heat stress is a key factor affecting forest plantation yields. While its effects are expected to worsen during this century, breeding more tolerant genotypes has proven elusive. We report here a substantial and durable increase in the thermotolerance of hybrid poplar (Populus tremula×Populus alba) through overexpression of a major small heat shock protein (sHSP) with convenient features. Experimental evidence was obtained linking protective effects in the transgenic events with the unique chaperone activity of sHSPs. In addition, significant positive correlations were observed between phenotype strength and heterologous sHSP accumulation. The remarkable baseline levels of transgene product (up to 1.8% of total leaf protein) have not been reported in analogous studies with herbaceous species. As judged by protein analyses, such an accumulation is not matched either by endogenous sHSPs in both heat-stressed poplar plants and field-grown adult trees. Quantitative real time-polymerase chain reaction analyses supported these observations and allowed us to identify the poplar members most responsive to heat stress. Interestingly, sHSP overaccumulation was not associated with pleiotropic effects that might decrease yields. The poplar lines developed here also outperformed controls under in vitro and ex vitro culture conditions (callus biomass, shoot production, and ex vitro survival), even in the absence of thermal stress. These results reinforce the feasibility of improving valuable genotypes for plantation forestry, a field where in vitro recalcitrance, long breeding cycles, and other practical factors constrain conventional genetic approaches. They also provide new insights into the biological functions of the least understood family of heat shock protein chaperones.
Asunto(s)
Adaptación Fisiológica/genética , Agricultura Forestal , Calentamiento Global , Proteínas de Choque Térmico Pequeñas/metabolismo , Calor , Hibridación Genética , Populus/fisiología , Adaptación Fisiológica/efectos de los fármacos , Aminobutiratos/farmacología , Estabilidad de Enzimas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Choque Térmico Pequeñas/genética , Respuesta al Choque Térmico/efectos de los fármacos , Respuesta al Choque Térmico/genética , Hippocastanaceae/efectos de los fármacos , Hippocastanaceae/metabolismo , Hibridación Genética/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Populus/efectos de los fármacos , Populus/genética , TransgenesRESUMEN
We used droplet digital PCR (ddPCR) assays to detect/quantify DNA from Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus spp. in blood samples. Bacterial DNA from clinical strains (4 < n < 12) was extracted, quantified and diluted (10-0.0001 ng/µL) and ddPCR assays were performed in triplicate. These ddPCR assays showed low replication variability, low detection limit (1-0.1 pg/µL), and genus/species specificity. ddPCR assays were also used to quantify bacterial DNA obtained from spiked blood (1 × 104-1 CFU/mL) of each bacterial genus/species. Comparison between ddPCR assays and bacterial culture was performed by Pearson correlation. There was an almost perfect correlation (r ≥ 0.997, P ≤ 0.001) between the number of CFU/mL from bacterial culture and the number of gene copies/mL detected by ddPCR. The time from sample preparation to results was determined to be 3.5 to 4 hours. The results demonstrated the quantification capacity and specificity of the ddPCR assays to detect/quantify 4 of the most important bloodstream infection (BSI) bacterial pathogens directly from blood. SIGNIFICANCE AND IMPACT: This pilot study results support the potential of ddPCR for the diagnosis and/or severity stratification of BSI. Applied to patients' blood samples it can improve diagnosis and diminish sample-to-results time, improving patient care.
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Escherichia coli , Sepsis , Humanos , ADN Bacteriano/genética , Proyectos Piloto , Reacción en Cadena de la Polimerasa/métodos , Escherichia coli/genética , Staphylococcus aureus/genéticaRESUMEN
Introduction: The present document has the objective of justifying the incorporation of a dietician/nutritionist to the multidisciplinary teams of specialized care that provide education, food anamnesis, nutritional recommendations, treatment and follow up of those patients in risk of malnutrition in Madrid. The appropriate nutritional status of hospitalized patients bears a close relationship with the existence of dieticians at hospitals. Dieticians use nutrition therapy as a cost-effective means to achieve significant health benefits by preventing or altering the course of diabetes, obesity, hypertension, lipid metabolism disorders, heart failure, osteoporosis, celiac disease, and chronic kidney disease, among other diseases.
Introducción: El presente documento tiene como objetivo plantear y justificar la incorporación del dietista-nutricionista en los equipos multidisciplinares de atención integrada en la educación, el tratamiento y el seguimiento de aquellos pacientes con patologías que cursen con alteraciones del estado nutricional, tanto en su defecto como en su exceso, en el área sanitaria de la Comunidad Autónoma de Madrid. El estado nutricional de los pacientes hospitalizados se beneficiará de la incorporación del dietista-nutricionista al equipo multidisciplinar que, actualmente, se ocupa de la atención de estos. El manejo de la terapia nutricional por dietistas-nutricionistas ha demostrado ser costo-efectiva, habida cuenta de la repercusión sanitaria que tiene el estado nutricional en la evolución clínica y prevención de enfermedades como la diabetes, los trastornos de la conducta alimentaria, la obesidad, el cáncer, la insuficiencia cardiaca, la osteoporosis, la enfermedad celiaca y la enfermedad renal crónica, entre otras.
Asunto(s)
Desnutrición , Nutricionistas , Humanos , Estado Nutricional , Hospitales Universitarios , Desnutrición/terapia , Apoyo NutricionalRESUMEN
Introduction: High levels of toxic steroidal glycoalkaloids (SGAs) in potato tubers constitute a recognized food quality problem. Tuber SGA levels vary between potato cultivars and can increase after post-harvest stresses such as wounding and light exposure. A few cultivars, e.g., 'Magnum Bonum' and 'Lenape,' have been withdrawn from commercial sales due to excessive SGA levels during some cultivation years. However, these sudden SGA increases are diffucult to predict, and their causes are not understood. To identify external and genetic factors that underlie sudden SGA increases in certain potato cultivars, we have here in a 2-year study investigated 'Magnum Bonum' and five additional table potato cultivars for their SGA levels after wounding and light exposure. Results and methods: Results showed that 'Magnum Bonum' has an unusual strong SGA response to light exposure, but not to wounding, whereas 'Bintje' displayed an opposite regulation. Levels of calystegine alkaloids were not significantly altered by treatments, implicating independent metabolic regulation of SGA and calystegine levels also under conditions of high SGA accumulation. Metabolomic and transcriptomic analyses identified a small number of key genes whose expression correlated with SGA differences between cultivars. Overexpression of two key genes in transgenic low-SGA potato cultivars increased their leaf SGA levels significantly. Discussion: The results show that a strong response to light can underlie the SGA peaks that occasionally occur in certain potato cultivars and indicate that a between-cultivar variation in the expression of single SGA key genes can account for cultivar SGA differerences. We propose that current attempts to mitigate the SGA hazard will benefit from an increased consideration of cultivar-dependent SGA responses to post-harvest conditions, particularly light exposure. The identified key SGA genes can now be used as a molecular tool in this work.
RESUMEN
BACKGROUND: Escherichia coli ST131, mainly its H30 clade, is the leading cause of extraintestinal E. coli infections but its correlates of virulence are undefined. MATERIALS AND METHODS: We tested in a murine sepsis model 84 ST131 isolates that differed by country of origin (Spain vs. USA), clonal subset, resistance markers, and virulence genes (VGs). Virulence outcomes, including illness severity score (ISS) and "killer" status (>80% mouse lethality), were compared statistically with clonal subset, individual and combined VGs, molecularly defined extraintestinal and uropathogenic E. coli (ExPEC, UPEC) status, and country of origin. RESULTS: Virulence varied widely by strain. Univariable correlates of median ISS and percent "killer" (outcomes if variable present vs. absent) included pap (ISS, 4.4 vs. 3.8; "killer", 71% vs. 46%), kpsMII (4.1 vs. 2.3; 59% vs. 25%), K2/K100 (4.4 vs. 3.2; 77% vs. 41%), ExPEC (4.2 vs. 2.2; 62% vs. 17%), Spanish origin (4.3 vs. 3.1; 65% vs. 36%), and H30R1 subset (2.5 vs. 4.1; 35% vs. 59%). With multivariable adjustment, ExPEC status was the only consistently significantly predictive variable. CONCLUSION: Within ST131 the strongest predictor of experimental virulence was molecularly defined ExPEC status. Clonal subsets seemed to behave differently in the murine sepsis model by country of origin.
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Escherichia coli Patógena Extraintestinal/genética , Escherichia coli Patógena Extraintestinal/patogenicidad , Sepsis/microbiología , Factores de Virulencia/genética , Animales , Técnicas de Tipificación Bacteriana , Modelos Animales de Enfermedad , Farmacorresistencia Bacteriana Múltiple , Infecciones por Escherichia coli/sangre , Infecciones por Escherichia coli/microbiología , Escherichia coli Patógena Extraintestinal/clasificación , Femenino , Ratones , Tipificación de Secuencias Multilocus , España , Organismos Libres de Patógenos Específicos , Estados Unidos , Virulencia/genética , beta-Lactamasas/genéticaRESUMEN
A key step in the metabolic degradation of biphenyl xenobiotics is catechol formation upon dehydrogenation of cis- and trans-dihydrodiols in prokaryotic and eukaryotic pathways, respectively. Structure and thermodynamics of stereoisomers of cis-, trans-2,3-biphenyl-dihydrodiols (I) and their dehydrogenation products (hydroxyketones, II), as well as final catechol (2,3-biphenyldiol, III) are studied by means of ab initio MP2/6-311++G(2df,2p)//MP2/6-311G(d,p) calculations. Formation of stereoisomers I and II is exothermic and endergonic, whereas III is enthalpically and entropically driven. Dehydrogenations are endothermic (DeltaHR0 approximately 1.5-4 kcal mol(-1)) and exergonic (DeltaGR0 approximately -5 to -7.5 kcal mol(-1)) without noticeable differences between cis and trans pathways, although the same keto stereoisomer II-(2S) is found to be the more favored product from both cis- and trans-I. The final II --> III tautomerization is thermodynamically enhanced (DeltaHR0 approximately -27, DeltaGR0 approximately -28 kcal mol(-1)) but the process is shown to have a large activation energy if it had to occur via unimolecular path. Although this tautomerization is generally assumed to be a nonenzymatic process as it involves rearomatization of an oxygenated ring, proton transfer with an anionic intermediate might be a more probable process.
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2,2'-Dipiridil/química , Calixarenos/metabolismo , Dioxigenasas/metabolismo , Naftalenos/química , Termodinámica , Xenobióticos/metabolismo , 2,2'-Dipiridil/metabolismo , Calixarenos/química , Catecoles/síntesis química , Catecoles/química , Simulación por Computador , Dioxigenasas/química , Modelos Químicos , Estructura Molecular , Naftalenos/metabolismo , Teoría Cuántica , Estereoisomerismo , Xenobióticos/químicaRESUMEN
Non-fermenting Gram-negative bacteria (NFGNB) are increasingly cultured in respiratory samples from cystic fibrosis (CF) patients. This study determined the antimicrobial susceptibility of clinical CF respiratory isolates from distinct geographical regions. A total of 286 isolates (106 Stenotrophomonas maltophilia, 100 Burkholderia spp., 59 Achromobacter spp., 12 Pandoraea spp., 9 Ralstonia spp.) from the Netherlands, Northern Ireland, Spain, USA and Australia were tested. MIC50/90 values and susceptibility categorisation were determined. Trimethoprim/sulfamethoxazole (SXT) was the most active compound for all micro-organisms (MIC50, 0.12-4 mg/L; MIC90, 1-16 mg/L). For S. maltophilia, 47% and 62% of isolates were susceptible to SXT according to CLSI and EUCAST breakpoints, respectively. Ceftazidime presented lower susceptibility (35%; MIC50, 32 mg/L; MIC90, 256 mg/L). MIC90 values for tobramycin and colistin were >128 mg/L and >16 mg/L, respectively. Regarding Burkholderia, 72%, 56% and 44% were susceptible to SXT, ceftazidime and meropenem, respectively. For both ceftazidime and meropenem, MIC50 and MIC90 values were within the intermediate or resistant category. The most active antibiotics for Achromobacter spp. were SXT (MIC50, 0.5 mg/L; MIC90, 8 mg/L) and imipenem (MIC50, 2 mg/L; MIC90, 8 mg/L). SXT, imipenem and ciprofloxacin were active against 12 Pandoraea spp. (MIC50, 0.12-4 mg/L; MIC90, 1-8 mg/L). Ciprofloxacin (MIC50, 4 mg/L) and SXT (MIC50, 1 mg/L) were the only active antibiotics for Ralstonia spp. There were no statistically significant differences in susceptibility rates between countries. NFGNB other than Pseudomonas aeruginosa are potential pathogens in CF. SXT was demonstrated to be the most active compound against these isolates.
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Antibacterianos/farmacología , Fibrosis Quística/microbiología , Farmacorresistencia Bacteriana , Bacterias Gramnegativas/efectos de los fármacos , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
El presente documento tiene como objetivo plantear y justificar la incorporación del dietista-nutricionista en los equipos multidisciplinares deatención integrada en la educación, el tratamiento y el seguimiento de aquellos pacientes con patologías que cursen con alteraciones del estadonutricional, tanto en su defecto como en su exceso, en el área sanitaria de la Comunidad Autónoma de Madrid.El estado nutricional de los pacientes hospitalizados se beneficiará de la incorporación del dietista-nutricionista al equipo multidisciplinar que,actualmente, se ocupa de la atención de estos. El manejo de la terapia nutricional por dietistas-nutricionistas ha demostrado ser costo-efectiva,habida cuenta de la repercusión sanitaria que tiene el estado nutricional en la evolución clínica y prevención de enfermedades como la diabetes,los trastornos de la conducta alimentaria, la obesidad, el cáncer, la insuficiencia cardiaca, la osteoporosis, la enfermedad celiaca y la enfermedadrenal crónica, entre otras.(AU)
The present document has the objective of justifying the incorporation of a dietician/nutritionist to the multidisciplinary teams of specialized carethat provide education, food anamnesis, nutritional recommendations, treatment and follow up of those patients in risk of malnutrition in Madrid.The appropriate nutritional status of hospitalized patients bears a close relationship with the existence of dieticians at hospitals. Dieticians usenutrition therapy as a cost-effective means to achieve significant health benefits by preventing or altering the course of diabetes, obesity, hyper-tension, lipid metabolism disorders, heart failure, osteoporosis, celiac disease, and chronic kidney disease, among other diseases.(AU)
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Humanos , Masculino , Femenino , Nutricionistas , Selección de Personal , Pacientes , Estado Nutricional , Terapia Nutricional , España , Hospitales Públicos , Desnutrición , Tamizaje MasivoRESUMEN
Replication of a damaged DNA template can threaten the integrity of the genome, requiring the use of various mechanisms to tolerate DNA lesions. The Smc5/6 complex, together with the Nse2/Mms21 SUMO ligase, plays essential roles in genome stability through undefined tasks at damaged replication forks. Various subunits within the Smc5/6 complex are substrates of Nse2, but we currently do not know the role of these modifications. Here we show that sumoylation of Smc5 is targeted to its coiled-coil domain, is upregulated by replication fork damage, and participates in bypass of DNA lesions. smc5-KR mutant cells display defects in formation of sister chromatid junctions and higher translesion synthesis. Also, we provide evidence indicating that Smc5 sumoylation modulates Mph1-dependent fork regression, acting synergistically with other pathways to promote chromosome disjunction. We propose that sumoylation of Smc5 enhances physical remodeling of damaged forks, avoiding the use of a more mutagenic tolerance pathway.
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Proteínas de Ciclo Celular/genética , Replicación del ADN/genética , Proteínas de Saccharomyces cerevisiae/genética , Sumoilación/genética , Cromátides/genética , Cromosomas/genética , ADN/genética , Daño del ADN/genética , Reparación del ADN/genética , Saccharomyces cerevisiae/genéticaRESUMEN
Somatic embryos can be used for propagating forest trees vegetatively, which is of great importance for capturing the genetic gain in breeding programs. However, many economically important Pinus species are difficult or impossible to propagate via somatic embryogenesis. In order to get a better understanding of the difficulties to propagate Pinus species via somatic embryogenesis, we are studying the developmental pathway of somatic embryos in different cell lines. In a previous study, we showed that the morphology of early somatic embryos in Scots pine (Pinus sylvestris) differs between cell lines giving rise to normal or abnormal cotyledonary embryos. In this study, we have compared the proliferation and degeneration pattern of early and late embryos in a normal and abnormal cell line. In both cell lines, a high frequency of the embryos degenerated. Among the degenerating embryos, two main degeneration patterns could be distinguished. In the normal cell line, the embryos degenerated similar to how the subordinate embryos are degraded in the seed. In the abnormal cell line, the degeneration of the embryos resulted in a continuous loop of embryo degeneration and differentiation of new embryos. We observed a similar degeneration pattern when embryogenic tissue was initiated from megagametophytes containing zygotic embryos at the stage of cleavage polyembryony. Based on our results, we suggest that the degeneration pattern in abnormal cell lines starts during initiation of embryogenic cultures.
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OBJECTIVE: To assess experimental virulence among sequence type 131 (ST131) Escherichia coli bloodstream isolates in relation to virulence genotype and subclone. METHODS: We analysed 48 Spanish ST131 bloodstream isolates (2010) by PCR for ST131 subclone status (H30Rx, H30 non-Rx, or non-H30), virulence genes (VGs), and O-type. Then we compared these traits with virulence in a murine sepsis model, as measured by illness severity score (ISS) and rapid lethality (mean ISS ≥ 4). RESULTS: Of the 48 study isolates, 65% were H30Rx, 21% H30 non-Rx, and 15% non-H30; 44% produced ESBLs, 98% were O25b, and 83% qualified as extraintestinal pathogenic E. coli (ExPEC). Of 49 VGs, ibeA and iss were associated significantly with non-H30 isolates, and sat, iha and malX with H30 isolates. Median VG scores differed by subclone, i.e., 12 (H30Rx), 10 (H30 non-Rx), and 11 (non-H30) (p < 0.01). Nearly 80% of isolates represented a described virotype. In mice, H30Rx and non-H30 isolates were more virulent than H30 non-Rx isolates (according to ISS [p = 0.03] and rapid lethality [p = 0.03]), as were ExPEC isolates compared with non-ExPEC isolates (median ISS, 4.3 vs. 2.7: p = 0.03). In contrast, most individual VGs, VG scores, VG profiles, and virotypes were not associated with mouse virulence. CONCLUSIONS: ST131 subclone and ExPEC status, but not individual VGs, VG scores or profiles, or virotypes, predicted mouse virulence. Given the lower virulence of non-Rx H30 isolates, hypervirulence probably cannot explain the ST131-H30 clade's epidemic emergence.
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Modelos Animales de Enfermedad , Infecciones por Escherichia coli/microbiología , Escherichia coli/genética , Sepsis/microbiología , Virulencia/genética , Animales , Femenino , Genes Bacterianos , Ratones , Reacción en Cadena de la Polimerasa , EspañaRESUMEN
Phylogenetic relationships among seed plant taxa, especially within the gymnosperms, remain contested. In contrast to angiosperms, for which several genomic, transcriptomic and phylogenetic resources are available, there are few, if any, molecular markers that allow broad comparisons among gymnosperm species. With few gymnosperm genomes available, recently obtained transcriptomes in gymnosperms are a great addition to identifying single-copy gene families as molecular markers for phylogenomic analysis in seed plants. Taking advantage of an increasing number of available genomes and transcriptomes, we identified single-copy genes in a broad collection of seed plants and used these to infer phylogenetic relationships between major seed plant taxa. This study aims at extending the current phylogenetic toolkit for seed plants, assessing its ability for resolving seed plant phylogeny, and discussing potential factors affecting phylogenetic reconstruction. In total, we identified 3,072 single-copy genes in 31 gymnosperms and 2,156 single-copy genes in 34 angiosperms. All studied seed plants shared 1,469 single-copy genes, which are generally involved in functions like DNA metabolism, cell cycle, and photosynthesis. A selected set of 106 single-copy genes provided good resolution for the seed plant phylogeny except for gnetophytes. Although some of our analyses support a sister relationship between gnetophytes and other gymnosperms, phylogenetic trees from concatenated alignments without 3rd codon positions and amino acid alignments under the CAT + GTR model, support gnetophytes as a sister group to Pinaceae. Our phylogenomic analyses demonstrate that, in general, single-copy genes can uncover both recent and deep divergences of seed plant phylogeny.