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1.
Crit Care Med ; 52(2): 258-267, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-37909832

RESUMEN

OBJECTIVES: Patients at risk of adverse effects related to positive fluid balance could benefit from fluid intake optimization. Less attention is paid to nonresuscitation fluids. We aim to evaluate the heterogeneity of fluid intake at the initial phase of resuscitation. DESIGN: Prospective multicenter cohort study. SETTING: Thirty ICUs across France and one in Spain. PATIENTS: Patients requiring vasopressors and/or invasive mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All fluids administered by vascular or enteral lines were recorded over 24 hours following admission and were classified in four main groups according to their predefined indication: fluids having a well-documented homeostasis goal (resuscitation fluids, rehydration, blood products, and nutrition), drug carriers, maintenance fluids, and fluids for technical needs. Models of regression were constructed to determine fluid intake predicted by patient characteristics. Centers were classified according to tertiles of fluid intake. The cohort included 296 patients. The median total volume of fluids was 3546 mL (interquartile range, 2441-4955 mL), with fluids indisputably required for body fluid homeostasis representing 36% of this total. Saline, glucose-containing high chloride crystalloids, and balanced crystalloids represented 43%, 27%, and 16% of total volume, respectively. Whatever the class of fluids, center of inclusion was the strongest factor associated with volumes. Compared with the first tertile, the difference between the volume predicted by patient characteristics and the volume given was +1.2 ± 2.0 L in tertile 2 and +3.0 ± 2.8 L in tertile 3. CONCLUSIONS: Fluids indisputably required for body fluid homeostasis represent the minority of fluid intake during the 24 hours after ICU admission. Center effect is the strongest factor associated with the volume of fluids. Heterogeneity in practices suggests that optimal strategies for volume and goals of common fluids administration need to be developed.


Asunto(s)
Enfermedad Crítica , Fluidoterapia , Humanos , Estudios Prospectivos , Enfermedad Crítica/terapia , Estudios de Cohortes , Fluidoterapia/efectos adversos , Soluciones Cristaloides , Resucitación
2.
Nat Commun ; 14(1): 7546, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37985771

RESUMEN

Bacillus subtilis can form various types of spatially organised communities on surfaces, such as colonies, pellicles and submerged biofilms. These communities share similarities and differences, and phenotypic heterogeneity has been reported for each type of community. Here, we studied spatial transcriptional heterogeneity across the three types of surface-associated communities. Using RNA-seq analysis of different regions or populations for each community type, we identified genes that are specifically expressed within each selected population. We constructed fluorescent transcriptional fusions for 17 of these genes, and observed their expression in submerged biofilms using time-lapse confocal laser scanning microscopy (CLSM). We found mosaic expression patterns for some genes; in particular, we observed spatially segregated cells displaying opposite regulation of carbon metabolism genes (gapA and gapB), indicative of distinct glycolytic or gluconeogenic regimes coexisting in the same biofilm region. Overall, our study provides a direct comparison of spatial transcriptional heterogeneity, at different scales, for the three main models of B. subtilis surface-associated communities.


Asunto(s)
Bacillus subtilis , Biopelículas , Bacillus subtilis/metabolismo , Microscopía Confocal , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo
3.
Respir Med Res ; 83: 101010, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37087906

RESUMEN

BACKGROUND: The present article is an English-language version of the French National Diagnostic and Care Protocol, a pragmatic tool to optimize and harmonize the diagnosis, care pathway, management and follow-up of lymphangioleiomyomatosis in France. METHODS: Practical recommendations were developed in accordance with the method for developing a National Diagnosis and Care Protocol for rare diseases of the Haute Autorité de Santé and following international guidelines and literature on lymphangioleiomyomatosis. It was developed by a multidisciplinary group, with the help of patient representatives and of RespiFIL, the rare disease network on respiratory diseases. RESULTS: Lymphangioleiomyomatosis is a rare lung disease characterised by a proliferation of smooth muscle cells that leads to the formation of multiple lung cysts. It occurs sporadically or as part of a genetic disease called tuberous sclerosis complex (TSC). The document addresses multiple aspects of the disease, to guide the clinicians regarding when to suspect a diagnosis of lymphangioleiomyomatosis, what to do in case of recurrent pneumothorax or angiomyolipomas, what investigations are needed to make the diagnosis of lymphangioleiomyomatosis, what the diagnostic criteria are for lymphangioleiomyomatosis, what the principles of management are, and how follow-up can be organised. Recommendations are made regarding the use of pharmaceutical specialties and treatment other than medications. CONCLUSION: These recommendations are intended to guide the diagnosis and practical management of pulmonary lymphangioleiomyomatosis.


Asunto(s)
Angiomiolipoma , Neoplasias Pulmonares , Linfangioleiomiomatosis , Esclerosis Tuberosa , Humanos , Linfangioleiomiomatosis/diagnóstico , Linfangioleiomiomatosis/terapia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/genética , Esclerosis Tuberosa/diagnóstico , Esclerosis Tuberosa/terapia , Esclerosis Tuberosa/genética , Pulmón , Angiomiolipoma/tratamiento farmacológico
4.
Front Pharmacol ; 14: 1125871, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36937867

RESUMEN

Acrylamide (ACR) is formed during food processing by Maillard reaction between sugars and proteins at high temperatures. It is also used in many industries, from water waste treatment to manufacture of paper, fabrics, dyes and cosmetics. Unfortunately, cumulative exposure to acrylamide, either from diet or at the workplace, may result in neurotoxicity. Such adverse effects arise from covalent adducts formed between acrylamide and cysteine residues of several neuronal proteins via a Michael addition reaction. The molecular determinants of acrylamide reactivity and its impact on protein function are not completely understood. Here we have compiled a list of acrylamide protein targets reported so far in the literature in connection with neurotoxicity and performed a systematic covalent docking study. Our results indicate that acrylamide binding to cysteine is favored in the presence of nearby positively charged amino acids, such as lysines and arginines. For proteins with more than one reactive Cys, docking scores were able to discriminate between the primary ACR modification site and secondary sites modified only at high ACR concentrations. Therefore, docking scores emerge as a potential filter to predict Cys reactivity against acrylamide. Inspection of the ACR-protein complex structures provides insights into the putative functional consequences of ACR modification, especially for non-enzyme proteins. Based on our study, covalent docking is a promising computational tool to predict other potential protein targets mediating acrylamide neurotoxicity.

5.
Appl Environ Microbiol ; 89(4): e0216222, 2023 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-36975784

RESUMEN

Bacteria of the genus Flavobacterium are recovered from a large variety of environments. Among the described species, Flavobacterium psychrophilum and Flavobacterium columnare cause considerable losses in fish farms. Alongside these well-known fish-pathogenic species, isolates belonging to the same genus recovered from diseased or apparently healthy wild, feral, and farmed fish have been suspected to be pathogenic. Here, we report the identification and genomic characterization of a Flavobacterium collinsii isolate (TRV642) retrieved from rainbow trout spleen. A phylogenetic tree of the genus built by aligning the core genome of 195 Flavobacterium species revealed that F. collinsii stands within a cluster of species associated with diseased fish, the closest one being F. tructae, which was recently confirmed as pathogenic. We evaluated the pathogenicity of F. collinsii TRV642 as well as of Flavobacterium bernardetii F-372T, another recently described species reported as a possible emerging pathogen. Following intramuscular injection challenges in rainbow trout, no clinical signs or mortalities were observed with F. bernardetii. F. collinsii showed very low virulence but was isolated from the internal organs of survivors, indicating that the bacterium is able to survive inside the host and may provoke disease in fish under compromised conditions such as stress and/or wounds. Our results suggest that members of a phylogenetic cluster of fish-associated Flavobacterium species may be opportunistic fish pathogens causing disease under specific circumstances. IMPORTANCE Aquaculture has expanded significantly worldwide in the last decades and accounts for half of human fish consumption. However, infectious fish diseases are a major bottleneck for its sustainable development, and an increasing number of bacterial species from diseased fish raise a great concern. The current study revealed phylogenetic associations with ecological niches among the Flavobacterium species. We also focused on Flavobacterium collinsii, which belongs to a group of putative pathogenic species. The genome contents revealed a versatile metabolic repertoire suggesting the use of diverse nutrient sources, a characteristic of saprophytic or commensal bacteria. In a rainbow trout experimental challenge, the bacterium survived inside the host, likely escaping clearance by the immune system but without provoking massive mortality, suggesting opportunistic pathogenic behavior. This study highlights the importance of experimentally evaluating the pathogenicity of the numerous bacterial species retrieved from diseased fish.


Asunto(s)
Enfermedades de los Peces , Infecciones por Flavobacteriaceae , Oncorhynchus mykiss , Animales , Humanos , Flavobacterium , Infecciones por Flavobacteriaceae/veterinaria , Infecciones por Flavobacteriaceae/microbiología , Filogenia , Enfermedades de los Peces/microbiología , Oncorhynchus mykiss/microbiología
6.
Nucleic Acids Res ; 51(6): 2974-2992, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-36919610

RESUMEN

Genome-scale engineering enables rational removal of dispensable genes in chassis genomes. Deviating from this approach, we applied greedy accumulation of deletions of large dispensable regions in the Bacillus subtilis genome, yielding a library of 298 strains with genomes reduced up to 1.48 Mb in size. High-throughput physiological phenotyping of these strains confirmed that genome reduction is associated with substantial loss of cell fitness and accumulation of synthetic-sick interactions. Transcriptome analysis indicated that <15% of the genes conserved in our genome-reduced strains exhibited a twofold or higher differential expression and revealed a thiol-oxidative stress response. Most transcriptional changes can be explained by loss of known functions and by aberrant transcription at deletion boundaries. Genome-reduced strains exhibited striking new phenotypes relative to wild type, including a very high resistance (increased >300-fold) to the DNA-damaging agent mitomycin C and a very low spontaneous mutagenesis (reduced 100-fold). Adaptive laboratory evolution failed to restore cell fitness, except when coupled with a synthetic increase of the mutation rate, confirming low evolvability. Although mechanisms underlying this emergent phenotype are not understood, we propose that low evolvability can be leveraged in an engineering strategy coupling reductive cycles with evolutive cycles under induced mutagenesis.


Asunto(s)
Bacillus subtilis , Genoma Bacteriano , Genoma Bacteriano/genética , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Fenotipo , Mutagénesis , Tasa de Mutación
7.
PLoS Genet ; 19(2): e1010618, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36735730

RESUMEN

Transcription termination factor Rho is known for its ubiquitous role in suppression of pervasive, mostly antisense, transcription. In the model Gram-positive bacterium Bacillus subtilis, de-repression of pervasive transcription by inactivation of rho revealed the role of Rho in the regulation of post-exponential differentiation programs. To identify other aspects of the regulatory role of Rho during adaptation to starvation, we have constructed a B. subtilis strain (Rho+) that expresses rho at a relatively stable high level in order to compensate for its decrease in the wild-type cells entering stationary phase. The RNAseq analysis of Rho+, WT and Δrho strains (expression profiles can be visualized at http://genoscapist.migale.inrae.fr/seb_rho/) shows that Rho over-production enhances the termination efficiency of Rho-sensitive terminators, thus reducing transcriptional read-through and antisense transcription genome-wide. Moreover, the Rho+ strain exhibits global alterations of sense transcription with the most significant changes observed for the AbrB, CodY, and stringent response regulons, forming the pathways governing the transition to stationary phase. Subsequent physiological analyses demonstrated that maintaining rho expression at a stable elevated level modifies stationary phase-specific physiology of B. subtilis cells, weakens stringent response, and thereby negatively affects the cellular adaptation to nutrient limitations and other stresses, and blocks the development of genetic competence and sporulation. These results highlight the Rho-specific termination of transcription as a novel element controlling stationary phase. The release of this control by decreasing Rho levels during the transition to stationary phase appears crucial for the functionality of complex gene networks ensuring B. subtilis survival in stationary phase.


Asunto(s)
Bacillus subtilis , Proteínas Bacterianas , Bacillus subtilis/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética , Ciclo Celular , Regulación Bacteriana de la Expresión Génica/genética
8.
PLoS Pathog ; 19(2): e1011127, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36730457

RESUMEN

Adherent-invasive Escherichia coli (AIEC) strains are frequently recovered from stools of patients with dysbiotic microbiota. They have remarkable properties of adherence to the intestinal epithelium, and survive better than other E. coli in macrophages. The best studied of these AIEC is probably strain LF82, which was isolated from a Crohn's disease patient. This strain contains five complete prophages, which have not been studied until now. We undertook their analysis, both in vitro and inside macrophages, and show that all of them form virions. The Gally prophage is by far the most active, generating spontaneously over 108 viral particles per mL of culture supernatants in vitro, more than 100-fold higher than the other phages. Gally is also over-induced after a genotoxic stress generated by ciprofloxacin and trimethoprim. However, upon macrophage infection, a genotoxic environment, this over-induction is not observed. Analysis of the transcriptome and key steps of its lytic cycle in macrophages suggests that the excision of the Gally prophage continues to be repressed in macrophages. We conclude that strain LF82 has evolved an efficient way to block the lytic cycle of its most active prophage upon macrophage infection, which may participate to its good survival in macrophages.


Asunto(s)
Bacteriófagos , Infecciones por Escherichia coli , Humanos , Escherichia coli , Macrófagos , Mucosa Intestinal , Adhesión Bacteriana
9.
Virulence ; 13(1): 1221-1241, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35880611

RESUMEN

Bacterial pathogens have a critical impact on aquaculture, a sector that accounts for half of the human fish consumption. Flavobacterium psychrophilum (phylum Bacteroidetes) is responsible for bacterial cold-water disease in salmonids worldwide. The molecular factors involved in host invasion, colonization and haemorrhagic septicaemia are mostly unknown. In this study, we identified two new TonB-dependent receptors, HfpR and BfpR, that are required for adaptation to iron conditions encountered during infection and for virulence in rainbow trout. Transcriptional analyses revealed that their expression is tightly controlled and upregulated under specific iron sources and concentrations. Characterization of deletion mutants showed that they act without redundancy: BfpR is required for optimal growth in the presence of high haemoglobin level, while HfpR confers the capacity to acquire nutrient iron from haem or haemoglobin under iron scarcity. The gene hfpY, co-transcribed with hfpR, encodes a protein related to the HmuY family. We demonstrated that HfpY binds haem and contributes significantly to host colonization and disease severity. Overall, these results are consistent with a model in which both BfpR and Hfp systems promote haem uptake and respond to distinct signals to adapt iron acquisition to the different stages of pathogenesis. Our findings give insight into the molecular basis of pathogenicity of a serious pathogen belonging to the understudied family Flavobacteriaceae and point to the newly identified haem receptors as promising targets for antibacterial development.


Asunto(s)
Enfermedades de los Peces , Infecciones por Flavobacteriaceae , Oncorhynchus mykiss , Animales , Enfermedades de los Peces/microbiología , Infecciones por Flavobacteriaceae/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Flavobacterium , Hemo/metabolismo , Humanos , Hierro/metabolismo , Oncorhynchus mykiss/metabolismo , Oncorhynchus mykiss/microbiología , Virulencia , Factores de Virulencia/genética
10.
Clin Microbiol Infect ; 28(1): 137.e1-137.e8, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34111580

RESUMEN

OBJECTIVES: Bacillus cereus is responsible for food poisoning and rare but severe clinical infections. The pathogenicity of strains varies from harmless to lethal strains. However, there are currently no markers, either alone or in combination, to differentiate pathogenic from non-pathogenic strains. The objective of the study was to identify new genetic biomarkers to differentiate non-pathogenic from clinically relevant B. cereus strains. METHODS: A first set of 15 B. cereus strains were compared by RNAseq. A logistic regression model with lasso penalty was applied to define combination of genes whose expression was associated with strain pathogenicity. The identified markers were checked for their presence/absence in a collection of 95 B. cereus strains with varying pathogenic potential (food-borne outbreaks, clinical and non-pathogenic). Receiver operating characteristic area under the curve (AUC) analysis was used to determine the combination of biomarkers, which best differentiate between the "disease" versus "non-disease" groups. RESULTS: Seven genes were identified during the RNAseq analysis with a prediction to differentiate between pathogenic and non-pathogenic strains. The validation of the presence/absence of these genes in a larger collection of strains coupled with AUC prediction showed that a combination of four biomarkers was sufficient to accurately discern clinical strains from harmless strains, with an AUC of 0.955, sensitivity of 0.9 and specificity of 0.86. CONCLUSIONS: These new findings help in the understanding of B. cereus pathogenic potential and complexity and may provide tools for a better assessment of the risks associated with B. cereus contamination to improve patient health and food safety.


Asunto(s)
Bacillus cereus , Microbiología de Alimentos , Marcadores Genéticos , Bacillus cereus/genética , Bacillus cereus/aislamiento & purificación , Filogenia , RNA-Seq , Virulencia
11.
Chembiochem ; 23(4): e202100640, 2022 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-34932835

RESUMEN

A genetic assay permits simultaneous quantification of two interacting proteins and their bound fraction at the single-cell level using flow cytometry. Apparent in-cellula affinities of protein-protein interactions can be extracted from the acquired data through a titration-like analysis. The applicability of this approach is demonstrated on a diverse set of interactions with proteins from different families and organisms and with in-vitro dissociation constants ranging from picomolar to micromolar.


Asunto(s)
Proteínas/química , Citometría de Flujo , Humanos , Unión Proteica , Análisis de la Célula Individual
12.
Int J Mol Sci ; 22(21)2021 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-34769504

RESUMEN

The optical control and investigation of neuronal activity can be achieved and carried out with photoswitchable ligands. Such compounds are designed in a modular fashion, combining a known ligand of the target protein and a photochromic group, as well as an additional electrophilic group for tethered ligands. Such a design strategy can be optimized by including structural data. In addition to experimental structures, computational methods (such as homology modeling, molecular docking, molecular dynamics and enhanced sampling techniques) can provide structural insights to guide photoswitch design and to understand the observed light-regulated effects. This review discusses the application of such structure-based computational methods to photoswitchable ligands targeting voltage- and ligand-gated ion channels. Structural mapping may help identify residues near the ligand binding pocket amenable for mutagenesis and covalent attachment. Modeling of the target protein in a complex with the photoswitchable ligand can shed light on the different activities of the two photoswitch isomers and the effect of site-directed mutations on photoswitch binding, as well as ion channel subtype selectivity. The examples presented here show how the integration of computational modeling with experimental data can greatly facilitate photoswitchable ligand design and optimization. Recent advances in structural biology, both experimental and computational, are expected to further strengthen this rational photopharmacology approach.


Asunto(s)
Activación del Canal Iónico/efectos de la radiación , Canales Iónicos/metabolismo , Optogenética/métodos , Animales , Sitios de Unión , Humanos , Ligandos , Luz , Simulación del Acoplamiento Molecular/métodos , Simulación de Dinámica Molecular , Procesos Fotoquímicos
13.
Microbiol Spectr ; 9(2): e0033021, 2021 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-34523994

RESUMEN

Flavobacterium psychrophilum, the etiological agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome, causes great economic losses in salmonid aquaculture worldwide. Recent molecular studies have uncovered important epidemiological and ecological aspects of this pathogen; however, such data are lacking for F. psychrophilum populations affecting aquaculture in China. Herein, F. psychrophilum phenotype, genotype, and virulence were characterized for isolates recovered from epizootics in multiple salmonid aquaculture facilities across China. Thirty-one F. psychrophilum isolates, originating from four provinces and three host fish species, were predominantly homogeneous biochemically but represented 5 sequence types (STs) according to multilocus sequence typing (MLST) that belonged to clonal complex CC-ST10 or 3 newly recognized singleton STs. PCR-based serotyping classified 19 and 12 F. psychrophilum isolates into molecular serotypes 1 and 0, respectively, showing an obvious relationship with host species. Antimicrobial susceptibility analysis via broth microdilution revealed reduced susceptibility to enrofloxacin, flumequine, and oxolinic acid, moderate susceptibility to gentamicin, erythromycin, and florfenicol, and variable susceptibility to ampicillin and oxytetracycline. In vivo challenge experiments confirmed the ability of two representative Chinese F. psychrophilum isolates to induce typical signs of BCWD and mortality in 1-year-old rainbow trout (Oncorhynchus mykiss). Findings collectively demonstrate (i) that BCWD outbreaks in China studied thus far are caused by F. psychrophilum lineages that are common on other continents (e.g., CC-ST10) and others that have not been reported elsewhere (e.g., ST355, ST356, ST357), (ii) that F. psychrophilum molecular serotypes distinguish isolates from different host fish species, even within STs, and (iii) reduced F. psychrophilum antimicrobial susceptibility against compounds used for BCWD control in China. IMPORTANCE Flavobacterium psychrophilum causes substantial economic losses in salmonid aquaculture worldwide. Although this bacterium is also believed to be a disease source in China, published reports of its presence do not yet exist. Herein, F. psychrophilum was linked to multiple disease outbreaks in several salmonid aquaculture facilities within four Chinese provinces, and polyphasic characterization revealed that most isolates were genetically distinct from strains recovered on other continents. Analyses further revealed the predominating molecular serotypes, antimicrobial susceptibility profiles, and pathogenic potential of two representative recovered isolates. Collectively, the results presented here provide important data on the epidemiology and disease ecology of F. psychrophilum in China and pave the way for targeted prevention and control methods to be pursued in the future.


Asunto(s)
Flavobacterium/efectos de los fármacos , Flavobacterium/genética , Oncorhynchus kisutch/microbiología , Oncorhynchus mykiss/microbiología , Osmeriformes/microbiología , Animales , Antibacterianos/farmacología , Acuicultura/economía , China , Enfermedades de los Peces/tratamiento farmacológico , Enfermedades de los Peces/microbiología , Enfermedades de los Peces/prevención & control , Flavobacterium/aislamiento & purificación , Flavobacterium/patogenicidad , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Factores de Virulencia/genética
14.
Int J Mol Sci ; 22(10)2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34064887

RESUMEN

Bacterial response to nitric oxide (NO) is of major importance for bacterial survival. NO stress is a main actor of the eukaryotic immune response and several pathogenic bacteria have developed means for detoxification and repair of the damages caused by NO. However, bacterial mechanisms of NO resistance by Gram-positive bacteria are poorly described. In the opportunistic foodborne pathogen Bacillus cereus, genome sequence analyses did not identify homologs to known NO reductases and transcriptional regulators, such as NsrR, which orchestrate the response to NO of other pathogenic or non-pathogenic bacteria. Using a transcriptomic approach, we investigated the adaptation of B. cereus to NO stress. A cluster of 6 genes was identified to be strongly up-regulated in the early phase of the response. This cluster contains an iron-sulfur cluster repair enzyme, a nitrite reductase and three enzymes involved in siroheme biosynthesis. The expression pattern and close genetic localization suggest a functional link between these genes, which may play a pivotal role in the resistance of B. cereus to NO stress during infection.


Asunto(s)
Bacillus cereus/metabolismo , Proteínas Bacterianas/metabolismo , Hemo/análogos & derivados , Hierro/metabolismo , Óxido Nítrico/toxicidad , Nitrito Reductasas/metabolismo , Estrés Oxidativo , Bacillus cereus/efectos de los fármacos , Bacillus cereus/genética , Bacillus cereus/crecimiento & desarrollo , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Hemo/biosíntesis , Transcripción Genética
15.
Bioinformatics ; 37(17): 2747-2749, 2021 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-33532816

RESUMEN

SUMMARY: Genoscapist is a tool to design web interfaces generating high-quality images for interactive visualization of hundreds of quantitative profiles along a reference genome together with various annotations. Relevance is demonstrated by deployment of two websites dedicated to large condition-dependent transcriptome datasets available for Bacillus subtilis and Staphylococcus aureus. AVAILABILITY AND IMPLEMENTATION: Websites and source code freely accessible at https://genoscapist.migale.inrae.fr.

16.
Mol Phylogenet Evol ; 158: 107044, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33346111

RESUMEN

The genus Gallus is distributed across a large part of Southeast Asia and has received special interest because the domestic chicken, Gallus gallus domesticus, has spread all over the world and is a major protein source for humans. There are four species: the red junglefowl (G. gallus), the green junglefowl (G. varius), the Lafayette's junglefowl (G. lafayettii) and the grey junglefowl (G. sonneratii). The aim of this study is to reconstruct the history of these species by a whole genome sequencing approach and resolve inconsistencies between well supported topologies inferred using different data and methods. Using deep sequencing, we identified over 35 million SNPs and reconstructed the phylogeny of the Gallus genus using both distance (BioNJ) and maximum likelihood (ML) methods. We observed discrepancies according to reconstruction methods and genomic components. The two most supported topologies were previously reported and were discriminated by using phylogenetic and gene flow analyses, based on ABBA statistics. Terminology fix requested by the deputy editor led to support a scenario with G. gallus as the earliest branching lineage of the Gallus genus, instead of G. varius. We discuss the probable causes for the discrepancy. A likely one is that G. sonneratii samples from parks or private collections are all recent hybrids, with roughly 10% of their autosomal genome originating from G. gallus. The removal of those regions is needed to provide reliable data, which was not done in previous studies. We took care of this and additionally included two wild G. sonneratii samples from India, showing no trace of introgression. This reinforces the importance of carefully selecting and validating samples and genomic components in phylogenomics.


Asunto(s)
Pollos/genética , Genoma , Animales , Evolución Biológica , Pollos/clasificación , ADN/química , ADN/metabolismo , ADN Mitocondrial/clasificación , ADN Mitocondrial/genética , Flujo Génico , Haplotipos , Funciones de Verosimilitud , Filogenia , Polimorfismo de Nucleótido Simple , Análisis de Componente Principal , Secuenciación Completa del Genoma
17.
ISME Commun ; 1(1): 33, 2021 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-36739365

RESUMEN

The family Flavobacteriaceae (phylum Bacteroidetes) is a major component of soil, marine and freshwater ecosystems. In this understudied family, Flavobacterium psychrophilum is a freshwater pathogen that infects salmonid fish worldwide, with critical environmental and economic impact. Here, we report an extensive transcriptome analysis that established the genome map of transcription start sites and transcribed regions, predicted alternative sigma factor regulons and regulatory RNAs, and documented gene expression profiles across 32 biological conditions mimicking the pathogen life cycle. The results link genes to environmental conditions and phenotypic traits and provide insights into gene regulation, highlighting similarities with better known bacteria and original characteristics linked to the phylogenetic position and the ecological niche of the bacterium. In particular, osmolarity appears as a signal for transition between free-living and within-host programs and expression patterns of secreted proteins shed light on probable virulence factors. Further investigations showed that a newly discovered sRNA widely conserved in the genus, Rfp18, is required for precise expression of proteases. By pointing proteins and regulatory elements probably involved in host-pathogen interactions, metabolic pathways, and molecular machineries, the results suggest many directions for future research; a website is made available to facilitate their use to fill knowledge gaps on flavobacteria.

18.
J R Soc Interface ; 17(171): 20200600, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33023397

RESUMEN

Automatic de novo identification of the main regulons of a bacterium from genome and transcriptome data remains a challenge. To address this task, we propose a statistical model that can use information on exact positions of the transcription start sites and condition-dependent expression profiles. The central idea of this model is to improve the probabilistic representation of the promoter DNA sequences by incorporating covariates summarizing expression profiles (e.g. coordinates in projection spaces or hierarchical clustering trees). A dedicated trans-dimensional Markov chain Monte Carlo algorithm adjusts the width and palindromic properties of the corresponding position-weight matrices, the number of parameters to describe exact position relative to the transcription start site, and chooses the expression covariates relevant for each motif. All parameters are estimated simultaneously, for many motifs and many expression covariates. The method is applied to a dataset of transcription start sites and expression profiles available for Listeria monocytogenes. The results validate the approach and provide a new global view of the transcription regulatory network of this important pathogen. Remarkably, a previously unreported motif is found in promoter regions of ribosomal protein genes, suggesting a role in the regulation of growth.


Asunto(s)
Listeria monocytogenes , Algoritmos , Listeria monocytogenes/genética , Cadenas de Markov , Modelos Estadísticos , Regiones Promotoras Genéticas , Transcriptoma
19.
Eur J Cancer Care (Engl) ; 29(4): e13245, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32567124

RESUMEN

OBJECTIVE: The 5-hydroxytryptamine-3 receptor antagonist palonosetron (PALO) is approved (United States/Europe) as an oral formulation for prevention of chemotherapy-induced nausea and vomiting in adult cancer patients undergoing moderately emetogenic chemotherapy (MEC) for the acute phase only, in the United States, or as intravenous (IV) formulation in patients undergoing MEC or highly emetogenic chemotherapy. This phase III study compares the efficacy/safety of oral versus IV PALO in Chinese patients. METHODS: Chemotherapy-naive patients with solid tumours scheduled for MEC received oral PALO 0.50 mg or IV PALO 0.25 mg. The primary objective was to demonstrate non-inferiority in terms of patients with complete response in the acute phase (0-24 hr post-chemotherapy). RESULTS: Complete response rates (acute phase), evaluated in 318/320 randomised patients, were 84.6% and 85.9% for oral and IV PALO respectively. Non-inferiority was demonstrated; the two formulations showed similar efficacy/safety. CONCLUSION: Non-inferiority of oral versus IV PALO in the acute phase was demonstrated in Chinese patients. CLINICAL TRIAL REGISTRATION: CTR20140711.


Asunto(s)
Antieméticos/administración & dosificación , Antineoplásicos/efectos adversos , Náusea/prevención & control , Neoplasias/tratamiento farmacológico , Palonosetrón/administración & dosificación , Vómitos/prevención & control , Administración Intravenosa , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/tratamiento farmacológico , Carcinoma/tratamiento farmacológico , China , Neoplasias Colorrectales/tratamiento farmacológico , Dexametasona/uso terapéutico , Método Doble Ciego , Femenino , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Neoplasias Gástricas/tratamiento farmacológico , Vómitos/inducido químicamente , Adulto Joven
20.
Vet Res ; 51(1): 60, 2020 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-32381115

RESUMEN

Tenacibaculum maritimum is responsible for tenacibaculosis, a devastating marine fish disease. This filamentous bacterium displays a very broad host range and a worldwide geographical distribution. We analyzed and compared the genomes of 25 T. maritimum strains, including 22 newly draft-sequenced genomes from isolates selected based on available MLST data, geographical origin and host fish. The genome size (~3.356 Mb in average) of all strains is very similar. The core genome is composed of 2116 protein-coding genes accounting for ~75% of the genes in each genome. These conserved regions harbor a moderate level of nucleotide diversity (~0.0071 bp-1) whose analysis reveals an important contribution of recombination (r/m ≥ 7) in the evolutionary process of this cohesive species that appears subdivided into several subgroups. Association trends between these subgroups and specific geographical origin or ecological niche remains to be clarified. We also evaluated the potential of MALDI-TOF-MS to assess the variability between T. maritimum isolates. Using genome sequence data, several detected mass peaks were assigned to ribosomal proteins. Additionally, variations corresponding to single or multiple amino acid changes in several ribosomal proteins explaining the detected mass shifts were identified. By combining nine polymorphic biomarker ions, we identified combinations referred to as MALDI-Types (MTs). By investigating 131 bacterial isolates retrieved from a variety of isolation sources, we identified twenty MALDI-Types as well as four MALDI-Groups (MGs). We propose this MALDI-TOF-MS Multi Peak Shift Typing scheme as a cheap, fast and an accurate method for screening T. maritimum isolates for large-scale epidemiological surveys.


Asunto(s)
Variación Genética , Genoma Bacteriano , Tenacibaculum/genética , Técnicas de Tipificación Bacteriana/veterinaria , Ensayos Analíticos de Alto Rendimiento/veterinaria , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/veterinaria
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