RESUMO
Lotus species are forage legumes with potential as pastures in low-fertility and environmentally constrained soils, owing to their high persistence and yield under those conditions. The aim of this work was the characterization of phenetic and genetic diversity of salt-tolerant bacteria able to establish efficient symbiosis with Lotus spp. A total of 180 isolates able to nodulate Lotus corniculatus and Lotus tenuis from two locations in Granada, Spain, were characterized. Molecular identification of the isolates was performed by repetitive extragenic palindromic PCR (REP-PCR) and 16S rRNA, atpD, and recA gene sequence analyses, showing the presence of bacteria related to different species of the genus Mesorhizobium: Mesorhizobium tarimense/Mesorhizobium tianshanense, Mesorhizobium chacoense/Mesorhizobium albiziae, and the recently described species, Mesorhizobium alhagi. No Mesorhizobium loti-like bacteria were found, although most isolates carried nodC and nifH symbiotic genes closely related to those of M. loti, considered the type species of bacteria nodulating Lotus, and other Lotus rhizobia. A significant portion of the isolates showed both high salt tolerance and good symbiotic performance with L. corniculatus, and many behaved like salt-dependent bacteria, showing faster growth and better symbiotic performance when media were supplemented with Na or Ca salts.
Assuntos
Alphaproteobacteria/classificação , Alphaproteobacteria/isolamento & purificação , Lotus/microbiologia , Raízes de Plantas/microbiologia , Microbiologia do Solo , Alphaproteobacteria/efeitos dos fármacos , Alphaproteobacteria/genética , Proteínas de Bactérias/genética , Cálcio/toxicidade , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , N-Acetilglucosaminiltransferases/genética , Oxirredutases/genética , Filogenia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Sais/toxicidade , Análise de Sequência de DNA , Sódio/toxicidade , EspanhaRESUMO
A total of 103 root nodule isolates were used to estimate the diversity of bacteria nodulating Lotus tenuis in typical soils of the Salado River Basin. A high level of genetic diversity was revealed by repetitive extragenic palindromic PCR, and 77 isolates with unique genomic fingerprints were further differentiated into two clusters, clusters A and B, after 16S rRNA restriction fragment length polymorphism analysis. Cluster A strains appeared to be related to the genus Mesorhizobium, whereas cluster B was related to the genus Rhizobium. 16S rRNA sequence and phylogenetic analysis further supported the distribution of most of the symbiotic isolates in either Rhizobium or Mesorhizobium: the only exception was isolate BA135, whose 16S rRNA gene was closely related to the 16S rRNA gene of the genus Aminobacter. Most Mesorhizobium-like isolates were closely related to Mesorhizobium amorphae, Mesorhizobium mediterraneum, Mesorhizobium tianshanense, or the broad-host-range strain NZP2037, but surprisingly few isolates grouped with Mesorhizobium loti type strain NZP2213. Rhizobium-like strains were related to Rhizobium gallicum, Rhizobium etli, or Rhizobium tropici, for which Phaseolus vulgaris is a common host. However, no nodC or nifH genes could be amplified from the L. tenuis isolates, suggesting that they have rather divergent symbiosis genes. In contrast, nodC genes from the Mesorhizobium and Aminobacter strains were closely related to nodC genes from narrow-host-range M. loti strains. Likewise, nifH gene sequences were very highly conserved among the Argentinian isolates and reference Lotus rhizobia. The high levels of conservation of the nodC and nifH genes suggest that there was a common origin of the symbiosis genes in narrow-host-range Lotus symbionts, supporting the hypothesis that both intrageneric horizontal gene transfer and intergeneric horizontal gene transfer are important mechanisms for the spread of symbiotic capacity in the Salado River Basin.
Assuntos
Alphaproteobacteria/classificação , Alphaproteobacteria/isolamento & purificação , Variação Genética , Lotus/microbiologia , Microbiologia do Solo , Alphaproteobacteria/genética , Argentina , Proteínas de Bactérias/genética , Análise por Conglomerados , Sequência Conservada , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genótipo , Dados de Sequência Molecular , N-Acetilglucosaminiltransferases/genética , Oxirredutases/genética , Filogenia , Raízes de Plantas/microbiologia , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
La enfermedad de von Willebrand es una entidad autosómica dominante de la coagulación relativamente frecuente, cuyo manejo anestésico se basa principalmente en la prevención de las alteraciones de la coagulación. En este trabajo se presenta el caso de una paciente con enfermedad de von Willebrand que fue sometida a una cirugía ginecológica, haciendo énfasis en su manejo perioperatorio, así como una revisión de la literatura acerca de los esquemas encaminados a lograr el control de la enfermedad en dicho caso
Assuntos
Humanos , Feminino , Adulto , Tiopental/administração & dosagem , Doenças de von Willebrand/cirurgia , Atracúrio/administração & dosagem , Fentanila , Histerectomia , Anestesia GeralRESUMO
Se realizó el presente estudio prospectivo, observacional, transversal y comparativo en el Departamento de Anestesiología del Hospital ABC, en 20 pacientes sometidos a cirugía abdominal con estado físico ASA I-II, sin medicación preanestésica, divididos en dos grupos en forma aleatoria. Grupo control: 10 pacientes con manejo anestésico con técnica inhalatoria con isofluorano; y grupo problema: 10 pacientes con técnica anestésica balanceada con isofluorano y dosis de cebamiento de citrato de fentanil (5 ug/kg) e infusión continua de 0.05 ug/kg/min, comparando constantes hemodinámicas y requerimientos anestésicos en ambos grupos durante la intubación e incisión quirúrgica, contra la toma de parámetros preinducción. Se contrastaron las variables obtenidas por el método de t de Student considerando como valores significativos P< 0.05. Se observó una disminución significativa de la tensión arterial media y frecuencia cardiaca en el grupo manejado con fentanil e infusión continua. Tanbién se observó una reducción en 50 por ciento del requerimiento anestésico en el mismo grupo, siendo significativo estadísticamente