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Background: Multidrug-resistant Acinetobacter baumannii is a common hospital-acquired pathogen. The increase in antibiotic resistance is commonly due to the acquisition of mobile genetic elements carrying antibiotic resistance genes. To comprehend this, we analyzed the resistome and virulome of Mexican A. baumannii multidrug-resistant isolates. Methods: Six clinical strains of A. baumannii from three Mexican hospitals were sequenced using the Illumina platform, the genomes were assembled with SPAdes and annotated with Prokka. Plasmid SPAdes and MobRecon were used to identify the potential plasmid sequences. Sequence Type (ST) assignation under the MLST Oxford scheme was performed using the PubMLST database. Homologous gene search for known virulent factors was performed using the virulence factor database VFDB and an in silico prediction of the resistome was conducted via the ResFinder databases. Results: The six strains studied belong to different STs and clonal complexes (CC): two strains were ST208 and one was ST369; these two STs belong to the same lineage CC92, which is part of the international clone (IC) 2. Another two strains were ST758 and one was ST1054, both STs belonging to the same lineage CC636, which is within IC5. The resistome analysis of the six strains identified between 7 to 14 antibiotic resistance genes to different families of drugs, including beta-lactams, aminoglycosides, fluoroquinolones and carbapenems. We detected between 1 to 4 plasmids per strain with sizes from 1,800 bp to 111,044 bp. Two strains from hospitals in Mexico City and Guadalajara had a plasmid each of 10,012 bp pAba78r and pAba79f, respectively, which contained the bla OXA-72 gene. The structure of this plasmid showed the same 13 genes in both strains, but 4 of them were inverted in one of the strains. Finally, the six strains contain 49 identical virulence genes related to immune response evasion, quorum-sensing, and secretion systems, among others. Conclusion: Resistance to carbapenems due to pAba78r and pAba79f plasmids in Aba pandrug-resistant strains from different geographic areas of Mexico and different clones was detected. Our results provide further evidence that plasmids are highly relevant for the horizontal transfer of antibiotic resistance genes between different clones of A. baumannii.
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Acinetobacter baumannii , Acinetobacter baumannii/genética , México , Tipagem de Sequências Multilocus , Antibacterianos/farmacologia , Carbapenêmicos , Fluoroquinolonas/farmacologia , Plasmídeos/genéticaRESUMO
Antimicrobial resistance (AR) is a major global threat to public health. Understanding the population dynamics of AR is critical to restrain and control this issue. However, no study has provided a global picture of the whole resistome of Acinetobacter baumannii, a very important nosocomial pathogen. Here we analyse 1450+ genomes (covering >40 countries and >4 decades) to infer the global population dynamics of the resistome of this species. We show that gene flow and horizontal transfer have driven the dissemination of AR genes in A. baumannii. We found considerable variation in AR gene content across lineages. Although the individual AR gene histories have been affected by recombination, the AR gene content has been shaped by the phylogeny. Furthermore, many AR genes have been transferred to other well-known pathogens, such as Pseudomonas aeruginosa or Klebsiella pneumoniae. Despite using this massive data set, we were not able to sample the whole diversity of AR genes, which suggests that this species has an open resistome. Our results highlight the high mobilization risk of AR genes between important pathogens. On a broader perspective, this study gives a framework for an emerging perspective (resistome-centric) on the genomic epidemiology (and surveillance) of bacterial pathogens.
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Acinetobacter baumannii/classificação , Proteínas de Bactérias/genética , Biologia Computacional/métodos , Farmacorresistência Bacteriana Múltipla , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Bases de Dados Genéticas , Fluxo Gênico , Transferência Genética Horizontal , Filogenia , Sequenciamento Completo do GenomaRESUMO
Understanding the interaction between genotype performance and the target environment is the key to improving genetic gain, particularly in the context of climate change. Wheat production is seriously compromised in agricultural regions affected by water and heat stress, such as the Mediterranean basin. Moreover, wheat production may be also limited by the nitrogen availability in the soil. We have sought to dissect the agronomic and physiological traits related to the performance of 12 high-yield European bread wheat varieties under Mediterranean rainfed conditions and different levels of N fertilization during two contrasting crop seasons. Grain yield was more than two times higher in the first season than the second season and was associated with much greater rainfall and lower temperatures. However, the nitrogen effect was rather minor. Genotypic effects existed for the two seasons. While several of the varieties from central/northern Europe yielded more than those from southern Europe during the optimal season, the opposite trend occurred in the dry season. The varieties from central/northern Europe were associated with delayed phenology and a longer crop cycle, while the varieties from southern Europe were characterized by a shorter crop cycle but comparatively higher duration of the reproductive period, associated with an earlier beginning of stem elongation and a greater number of ears per area. However, some of the cultivars from northern Europe maintained a relatively high yield capacity in both seasons. Thus, KWS Siskin from the UK exhibited intermediate phenology, resulting in a relatively long reproductive period, together with a high green area throughout the crop cycle.
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Introducción: La ejecución de maniobras de reanimación cardiopulmonar por las personas que han presenciado un paro aumenta siete veces las posibilidades de supervivencia. Objetivo: Evaluar la efectividad de una demostración de situación clínica simulada realizada en los domicilios para elevar el nivel de conocimientos sobre reanimación cardiopulmonar básica en el adulto. Métodos: Se realizó un estudio de tipo antes y después sin grupo control entre septiembre y diciembre de 2018. El universo estuvo conformado por 620 pacientes pertenecientes a un consultorio del policlínico 19 de abril de Plaza de la Revolución. Se seleccionó una muestra de 200 pacientes y se les aplicó una encuesta, realizada por los autores, antes y después de la intervención, la cual se sometió a test alfa para la validación interna. Para la evaluación de la demostración se utilizó la prueba t de student, un análisis de varianza (ANOVA) y un análisis post hoc. Resultados: La media de edad fue de 45,45 ± 14,45 años. El sexo femenino predominó con 102 personas (51 por ciento). Hubo 63 (32 por ciento) pacientes con nivel de técnico medio. La diferencia de las medias de puntos antes y después de la demostración fue estadísticamente significativa en todos los grados de escolaridad (p ˂ 0,001). Hubo diferencias en el aumento de puntos después de la demostración entre los universitarios y las personas con sexto grado (p = 0,013). Conclusiones: Realizar una demostración con una situación clínica simulada constituyó una herramienta efectiva para elevar el nivel de conocimiento de la población en estudio, independientemente del nivel de escolaridad(AU)
Introduction: Bystander cardiopulmonary resuscitation increases the chances of survival by seven times. Objective: To assess the effectiveness of a simulated clinical situation carried out in homes to raise the level of knowledge about basic cardiopulmonary resuscitation in adults. Methods: A before-and-after study without a control group was carried out between September and December 2018. The universe consisted of 620 patients from a family doctor's office belonging to 19 de Abril Outpatient Polyclinic in Plaza de la Revolución Municipality (Havana, Cuba). A sample of 200 patients was selected and a survey was applied on them, carried out by the authors, before and after the intervention, which was subjected to an alpha test for internal validation. For the assessment of the demonstration, Student's t test, variance analysis (ANOVA) and a post hoc analysis were used. Results: The mean age was 45.45 ± 14.45 years. The female sex predominated, with 102 people (51 percent). There were 63 (32 percent) patients with an associate's degree. The difference in the means of scores before and after the demonstration was statistically significant in all school levels (P˂0.001). There were differences in the increase of scores after the simulated performance between the university students and the people with sixth grade (P=0.013). Conclusions: Performance of a simulated clinical situation was an effective tool to raise the level of knowledge of the population under study, regardless of their level of education(AU)
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Humanos , Adulto , Pessoa de Meia-Idade , Avaliação de Resultado de Ações Preventivas , Reanimação Cardiopulmonar/educação , Conhecimento , Promoção da Saúde , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados não Aleatórios como Assunto , Visita DomiciliarRESUMO
Resumen.Objetivo. Determinar las diferencias inter-género del optimismo disposicional, la depresión, la ansiedad, el estrés y el rol predictor sobre estos rasgos patológicos en una muestra de universitarios del Ecuador. Método. Investigación descriptiva, comparativa, predictora y de corte transversal con las pruebas de Orientación Vital y la Escala de Depresión, Ansiedad y Estrés con 288 participantes de una universidad pública de Ambato, Ecuador (63.9% son mujeres y 31% hombres). Con edades entre 17 a 39 años (M = 21.6 años; DT = 2.5). Resultados. Hay diferencias (p < .05) de género en ansiedad y estrés (con mayor presencia en mujeres que en hombres. También, hay correlaciones entre el optimismo disposicional y los rasgos patológicos. Finalmente, el optimismo disposicional explica en la depresión (15.2%), la ansiedad (9.7%) y el estrés (5.5%) los cambios de la varianza. Se concluye que el optimismo disposicional es un predictor de la depresión, la ansiedad y el estrés en estudiantes universitarios.
Abstract.Objective. To determine the inter-gender differences in dispositional optimism, depression, anxiety, and stress; as well as the predictive role of optimism on pathological features in a sample of Ecuadorian university students. Method. This is a descriptive, comparative, predictive and cross-sectional study using the Life Orientation (LOT-R) and Depression, Anxiety and Stress Scale (DASS-21) tests with 288 university students belonging to one university of Ambato; 63.9% women, 31% men aged between 17 to 39 (M = 21.6 years, SD = 2.5). Results. Gender differences were found at the Anxiety and Stress level, with greater presence in women than in men. As regards dispositional optimism and depression, gender is invariant. There were both slight and significant correlations between dispositional optimism and the dimensions evaluated by the DASS 21 test. Dispositional optimism also explains changes in variance in depression (15.2%), anxiety (9.7%) and stress (5.5%). As a conclusion, dispositional optimism is a relevant predictor of depression, as well as anxiety and stress in university students.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Ansiedade/psicologia , Estresse Psicológico , Depressão/psicologia , Estudantes , Equador , Otimismo/psicologia , PessimismoRESUMO
RESUMEN El tabaco es una de las drogas legales más consumida en el mundo, y es el cigarro la forma más común de consumo. Cuba tiene las cifras más altas respecto al resto de los países del Caribe, por lo que el tabaquismo constituye un importante problema de salud. Debido a esto y a los nuevos descubrimientos relacionados con este campo, se realizó una revisión bibliográfica para exponer los hallazgos más actuales acerca del trastorno por consumo de tabaco, o tabaquismo. Todo ello se soportó sobre la consulta de más de 60 fuentes documentales, de las cuales se tomaron 55 como referencia bibliográfica. Los mecanismos neurofisiopatológicos que intervienen son la activación de los RnAc α4β2, y en menor medida, los α6β2. El diagnóstico se realiza mediante las pautas establecidas por la Sociedad Americana de Psiquiatría. Los efectos de la nicotina sobre el organismo incluyen daños al sistema cardiovascular, respiratorio, hematológico, endocrino y nervioso. Los avances logrados en el tratamiento, tanto desde el punto vista psicosocial, como farmacológico, han logrado buenos resultados, aunque todavía existen aristas inexploradas.
ABSTRACT Tobacco is one of the most consumed legal drugs in the world, and cigar is the most common form of consumption. Cuba has the highest figures compared to the rest of the Caribbean countries, reason for which smoking is a major health problem. Due to this and the new discoveries related to this field, a bibliographic review was conducted to show the updated findings about the tobacco use disorder, or smoking. This was supported on the review of more than 60 documentary sources, 55 of them were taken as a bibliographic reference. The neurophysiological mechanisms involved are the activation of RnAc α4β2, and to a lesser extent, α6β2. The diagnosis is made through the guidelines established by the American Psychiatric Society. The effects of nicotine on the body include damage to the cardiovascular, respiratory, hematological, endocrine, and nervous systems. Although there are still unexplored areas, the treatment, from the psychosocial point of view and pharmacological, has achieved good results.
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BACKGROUND: Members of the Bacillus genus have been isolated from a variety of environments. However, the relationship between potential metabolism and the niche from which bacteria of this genus have been isolated has not been extensively studied. The existence of a monophyletic aquatic Bacillus group, composed of members isolated from both marine and fresh water has been proposed. Here, we present a phylogenetic/phylogenomic analysis to investigate the potential relationship between the environment from which group members have been isolated and their evolutionary origin. We also carried out hierarchical clustering based on functional content to test for potential environmental effects on the genetic content of these bacteria. RESULTS: The phylogenetic reconstruction showed that Bacillus strains classified as aquatic have evolutionary origins in different lineages. Although we observed the presence of a clade consisting exclusively of aquatic Bacillus, it is not comprised of the same strains previously reported. In contrast to phylogeny, clustering based on the functional categories of the encoded proteomes resulted in groups more compatible with the environments from which the organisms were isolated. This evidence suggests a detectable environmental influence on bacterial genetic content, despite their different evolutionary origins. CONCLUSION: Our results suggest that aquatic Bacillus species have polyphyletic origins, but exhibit convergence at the gene content level.
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Bacillus/classificação , Bacillus/genética , Meio Ambiente , Genes Bacterianos , Análise por Conglomerados , Evolução Molecular , Genômica , FilogeniaRESUMO
Resumen Se indaga sobre la predictibilidad de la Satisfacción con la vida y el Bienestar Psicológico y Social en la Salud Mental en una muestra de estudiantes universitarios del Ecuador a través de un análisis descriptivo de predicción, comparativo por sexo y universidad. Es un estudio de corte transversal en el que participaron 982 estudiantes de tres universidades de Cuenca y Ambato, en Ecuador. Se encontró que el bienestar subjetivo, psicológico y social predicen el 55.1% de explicación de la varianza de Salud Mental. Además, existen diferencias por género en la Satisfacción con la vida (t = -1.98; p < .05) y el Bienestar Social (t = -2.34; p < .05), en este último las mujeres puntúan más que los hombres. También hay diferencias por el tipo de universidad en la Satisfacción con la vida (t = -3.11; p < .01), el Bienestar Psicológico (t = -3.21; p < .01) y la Salud Mental (t = -2.22; p < .05) con mejores puntajes en la universidad cofinanciada. Con estos elementos, se concluye que los distintos indicadores del bienestar individual predicen considerablemente la salud mental.
Abstract The predictability of Satisfaction of the Life and the Psychological and Social well-being in Mental Health in a sample of university students from Ecuador is explored through a descriptive analysis of prediction, comparative by sex and university; and of cross section in which 982 students participated from three universities from Cuenca and Ambato in Ecuador. It was found that subjective, psychological and social well-being predict 55.1% of explination of the Mental Health variance. Further, there are differences by gender in Satisfaction with life (t = -1.98; p < .05) and Social Welfare (t = -2.34; p < .05) in which women score more than men; and by the type of university in the Satisfaction with the life (t = -3.11; p < .01), the Psychological Well-being (t = -3.21; p < .01) and the Mental Health (t = -2.22; p < .05) with better scores in the co-financed university. With these elements, it is concluded that the different indicators of individual well-being significantly predict mental health.
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Humanos , Masculino , Feminino , Adulto , Satisfação Pessoal , Seguridade Social/psicologia , Estudantes/psicologia , Saúde Mental , Universidades , EquadorRESUMO
In the last decades, studies about the specific effects of bioactive glass on remineralization of dentin were the focus of attention, due to their excellent regenerative properties in mineralized tissues. The incorporation of Fluorine in bioactive glass nanoparticles may result in the formation of fluorapatite (FAP), which is chemically more stable than hydroxyapatite or carbonated hydroxyapatite, and therefore is of interest for dental applications. The aim of this study was to synthesize and characterize a new system of Fluorine-containing bioactive glass nanoparticles (BGNPF). A sol-gel route assisted by ultrasound was used for the synthesis of BGNPF. The particles obtained were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD), dynamic light scattering (DLS), nitrogen adsorption, and X-ray photoelectron spectroscopy (XPS). SEM micrographs showed that the particles are quite uniform spherical nanostructures, occurring agglomeration or partial sinterization of the particulate system after heat treatment. XRD and XPS analysis results suggest the formation of fluorapatite crystals embedded within the matrix of the bioactive glass nanoparticles. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 360-366, 2018.
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Flúor/química , Vidro/química , Nanopartículas/química , Transição de Fase , Ondas UltrassônicasRESUMO
The draft genome sequence of Avibacterium paragallinarum strain CL serovar C is reported here. The genome comprises 154 contigs corresponding to 2.4 Mb with 41% G+C content and many insertion sequence (IS) elements, a characteristic not previously reported in A. paragallinarum.
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Bacillus aquimaris TF12 is a Gram-positive bacteria isolated from a tidal flat of the Yellow Sea in South Korea. We report the draft whole-genome sequence of Bacillus aquimaris TF12, the type strain of a set of bacteria typically associated with marine habitats and with a potentially high biotechnology value.
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Members of the Bacillus genus have been extensively studied because of their ability to produce enzymes with high biotechnological value. Here, we report the draft of the whole-genome sequence of the type strain Bacillus horikoshii DSM 8719, an alkali-tolerant strain.
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Bacterial genomes undergo numerous events of gene losses and gains that generate genome variability among strains of the same species (microevolution). Our aim was to compare the genomes and relevant phenotypes of three Bacillus coahuilensis strains from two oligotrophic hydrological systems in the Cuatro Ciénegas Basin (México), to unveil the environmental challenges that this species cope with, and the microevolutionary differences in these genotypes. Since the strains were isolated from a low P environment, we placed emphasis on the search of different phosphorus acquisition strategies. The three B. coahuilensis strains exhibited similar numbers of coding DNA sequences, of which 82% (2,893) constituted the core genome, and 18% corresponded to accessory genes. Most of the genes in this last group were associated with mobile genetic elements (MGEs) or were annotated as hypothetical proteins. Ten percent of the pangenome consisted of strain-specific genes. Alignment of the three B. coahuilensis genomes indicated a high level of synteny and revealed the presence of several genomic islands. Unexpectedly, one of these islands contained genes that encode the 2-keto-3-deoxymannooctulosonic acid (Kdo) biosynthesis enzymes, a feature associated to cell walls of Gram-negative bacteria. Some microevolutionary changes were clearly associated with MGEs. Our analysis revealed inconsistencies between phenotype and genotype, which we suggest result from the impossibility to map regulatory features to genome analysis. Experimental results revealed variability in the types and numbers of auxotrophies between the strains that could not consistently be explained by in silico metabolic models. Several intraspecific differences in preferences for carbohydrate and phosphorus utilization were observed. Regarding phosphorus recycling, scavenging, and storage, variations were found between the three genomes. The three strains exhibited differences regarding alkaline phosphatase that revealed that in addition to gene gain and loss, regulation adjustment of gene expression also has contributed to the intraspecific diversity of B. coahuilensis.
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Understanding the principles that govern community assemblages is a central goal of ecology. There is limited experimental evidence in natural settings showing that microbial assembly in communities are influenced by antagonistic interactions. We, therefore, analyzed antagonism among bacterial isolates from a taxonomically related bacterial guild obtained from five sites in sediments from a fresh water system. We hypothesized that if antagonistic interactions acted as a shaping force of the community assembly, then the frequency of resistance to antagonism among bacterial isolates originating from a given site would be higher than the resistance to conspecifics originating from a different assemblage. Antagonism assays were conducted between 78 thermoresistant isolates, of which 72 were Bacillus spp. Sensitive, resistant and antagonistic isolates co-occurred at each site, but the within-site frequency of resistance observed was higher than that observed when assessed across-sites. We found that antagonism results from bacteriocin-like substances aimed at the exclusion of conspecifics. More than 6000 interactions were scored and described by a directed network with hierarchical structure that exhibited properties that resembled a food chain, where the different Bacillus taxonomic groups occupied specific positions. For some tested interacting pairs, the unidirectional interaction could be explained by competition that inhibited growth or completely excluded one of the pair members. This is the first report on the prevalence and specificity of Bacillus interactions in a natural setting and provides evidence for the influence of bacterial antagonist interactions in the assemblage of a taxonomically related guild in local communities.
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Antibiose/fisiologia , Bacillus/fisiologia , Biodiversidade , Cadeia Alimentar , Sedimentos Geológicos/microbiologia , Bacillus/classificação , Bacillus/genética , Água Doce , Variação Genética , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Studies of Mycobacterium bovis BCG strains used in different countries and vaccination programs show clear variations in the genomes and immune protective properties of BCG strains. The aim of this study was to characterise the genomic and immune proteomic profile of the BCG 1931 strain used in Mexico. RESULTS: BCG Mexico 1931 has a circular chromosome of 4,350,386 bp with a G+C content and numbers of genes and pseudogenes similar to those of BCG Tokyo and BCG Pasteur. BCG Mexico 1931 lacks Region of Difference 1 (RD1), RD2 and N-RD18 and one copy of IS6110, indicating that BCG Mexico 1931 belongs to DU2 group IV within the BCG vaccine genealogy. In addition, this strain contains three new RDs, which are 53 (RDMex01), 655 (RDMex02) and 2,847 bp (REDMex03) long, and 55 single-nucleotide polymorphisms representing non-synonymous mutations compared to BCG Pasteur and BCG Tokyo. In a comparative proteomic analysis, the BCG Mexico 1931, Danish, Phipps and Tokyo strains showed 812, 794, 791 and 701 protein spots, respectively. The same analysis showed that BCG Mexico 1931 shares 62% of its protein spots with the BCG Danish strain, 61% with the BCG Phipps strain and only 48% with the BCG Tokyo strain. Thirty-nine reactive spots were detected in BCG Mexico 1931 using sera from subjects with active tuberculosis infections and positive tuberculin skin tests. CONCLUSIONS: BCG Mexico 1931 has a smaller genome than the BCG Pasteur and BCG Tokyo strains. Two specific deletions in BCG Mexico 1931 are described (RDMex02 and RDMex03). The loss of RDMex02 (fadD23) is associated with enhanced macrophage binding and RDMex03 contains genes that may be involved in regulatory pathways. We also describe new antigenic proteins for the first time.
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Mycobacterium bovis/genética , Tuberculose/imunologia , Genoma Bacteriano , Humanos , Dados de Sequência Molecular , Mycobacterium bovis/metabolismo , Polimorfismo de Nucleotídeo Único , Proteoma/metabolismo , Análise de Sequência de DNA , Tuberculose/patologiaRESUMO
Ni nanoparticles were synthesized using two water-in-oil emulsions formulated with different surfactants and using n-heptane as the organic phase and aqueous nickel acetate as the catalytic metallic precursor. Characterization by transmission electron microscopy showed that the Ni nanoparticles have diameters ranging from 3 to 12 nm, and that the surface is lightly oxidized. The decomposition of diluted methane catalyzed by the as-prepared Ni nanoparticles was studied in a thermogravimetric analyzer (TGA), operated in the 25-930°C range. The weight gains measured during the analysis showed that the Ni nanoparticles decomposed methane above 480°C, producing similar g.C/g.cat ratios (6-7) at the end of the tests. High resolution transmission electron microscopy (HRTEM) confirmed that the carbons collected at 930°C were bamboo-shaped carbon nanotubes (BSCNTs) with well defined conical compartments. The average outside diameter of the tubes was between 30 and 60 nm.
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Insertion sequences (IS) are mobile genetic elements that are distributed in many prokaryotes. In particular, in the genomes of the symbiotic nitrogen-fixing bacteria collectively known as rhizobia, IS are fairly abundant in plasmids or chromosomal islands that carry the genes needed for symbiosis. Here, we report an analysis of the distribution and genetic conservation of the IS found in the genome of Rhizobium etli CFN42 in a collection of 87 Rhizobium strains belonging to populations with different geographical origins. We used PCR to generate presence/absence profiles of the 39 IS found in R. etli CFN42 and evaluated whether the IS were located in consistent genomic contexts. We found that the IS from the symbiotic plasmid were frequently present in the analyzed strains, whereas the chromosomal IS were observed less frequently. We then examined the evolutionary dynamics of these strains based on a population genetic analysis of two chromosomal housekeeping genes (glyA and dnaB) and three symbiotic sequences (nodC and the two IS elements). Our results indicate that the IS contained within the symbiotic plasmid have a higher degree of genomic context conservation, lower nucleotide diversity and genetic differentiation, and fewer recombination events than the chromosomal housekeeping genes. These results suggest that the R. etli populations diverged recently in Mexico, that the symbiotic plasmid also had a recent origin, and that the IS elements have undergone a process of cyclic infection and expansion.
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Cromossomos Bacterianos , Elementos de DNA Transponíveis , Evolução Molecular , Plasmídeos , Polimorfismo Genético , Rhizobium etli/genética , Proteínas de Bactérias/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , México , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de SequênciaRESUMO
Strains of the same bacterial species often show considerable genomic variation. To examine the extent of such variation in Rhizobium etli, the complete genome sequence of R. etli CIAT652 and the partial genomic sequences of six additional R. etli strains having different geographical origins were determined. The sequences were compared with each other and with the previously reported genome sequence of R. etli CFN42. DNA sequences common to all strains constituted the greater part of these genomes and were localized in both the chromosome and large plasmids. About 700 to 1,000 kb of DNA that did not match sequences of the complete genomes of strains CIAT652 and CFN42 was unique to each R. etli strain. These sequences were distributed throughout the chromosome as individual genes or chromosomal islands and in plasmids, and they encoded accessory functions, such as transport of sugars and amino acids, or secondary metabolism; they also included mobile elements and hypothetical genes. Sequences corresponding to symbiotic plasmids showed high levels of nucleotide identity (about 98 to 99%), whereas chromosomal sequences and the sequences with matches to other plasmids showed lower levels of identity (on average, about 90 to 95%). We concluded that R. etli has a pangenomic structure with a core genome composed of both chromosomal and plasmid sequences, including a highly conserved symbiotic plasmid, despite the overall genomic divergence.
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DNA Bacteriano/genética , Genoma Bacteriano , Plasmídeos , Rhizobium etli/genética , Análise por Conglomerados , Sequência Conservada , DNA Bacteriano/química , Ilhas Genômicas , Dados de Sequência Molecular , Filogenia , Rhizobium etli/fisiologia , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
La osteoporosis es un padecimiento por disminución de la masa ósea por unidad de volumen, que compromete la competencia mecánica del esqueleto. Es debida a aumento de reabsorción ósea, a disminución de la formación de hueso o a una combinación de ambos procesos. Es inducida por múltiples factores. Su tratamiento involucra un proceso diagnóstico que determina primero la pérdida del componente óseo mineral y después el tipo de alteración del remodelamiento. A partir de esto, se decide el tipo de tratamiento a seguir, ya sea con formadores de hueso o con anti-reabsorbentes