The Plasmid Mobilome of the Model Plant-Symbiont Sinorhizobium meliloti: Coming up with New Questions and Answers

Rhizobia are Gram-negative Alpha- andBetaproteobacteria living in the underground that have theability to associate with legumes for the establishment ofnitrogen-fixing symbioses.Sinorhizobium melilotiinparticular—the symbiont ofMedicago,Melilotus, andTrigonellaspp.—has for the past decades served as a model organism forinvestigating, at the molecular level, the biology, biochemistry,and genetics of a free-living and symbiotic soil bacterium ofagricultural relevance. To date, the genomes of seven differentS. melilotistrains have been fully sequenced and annotated,and several other draft genomic sequences are also available(http://www.ncbi.nlm.nih.gov/genome/genomes/1004).The vast amount of plasmid DNA thatS. melilotifrequently bears(up to 45% of its total genome), the conjugative ability of some ofthose plasmids, and the extent of the plasmid diversity hasprovided researchers with an extraordinary system to investigatefunctional and structural plasmid molecular biology within theevolutionary context surrounding a plant-associated modelbacterium. Current evidence indicates that the plasmidmobilome inS. melilotiis composed of replicons varying greatlyin size and having diverse conjugative systems and propertiesalong with different evolutionary stabilities and biological roles.While plasmids carrying symbiotic functions (pSyms) are knownto have high structural stability (approaching that ofchromosomes), the remaining plasmid mobilome (referred to asthe non-pSym,functionally cryptic,oraccessorycompartment)has been shown to possess remarkable diversity and to be highlyactive in conjugation. In light of the modern genomic andcurrent biochemical data on the plasmids ofS. meliloti,the current article revises their main structural components,their transfer and regulatory mechanisms, and their potentialas vehicles in shaping the evolution of the rhizobial genome.Fil: Lagares, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Sanjuán Pinilla, Juan. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Pistorio, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Comparative genomic analysis of Acinetobacter spp. plasmids originating from clinical settings and environmental habitats

Bacteria belonging to the genus Acinetobacter have become of clinical importance over the last decade due to the development of a multi-resistant phenotype and their ability to survive under multiple environmental conditions. The development of these traits among Acinetobacter strains occurs frequently as a result of plasmid-mediated horizontal gene transfer. In this work, plasmids from nosocomial and environmental Acinetobacter spp. collections were separately sequenced and characterized. Assembly of the sequenced data resulted in 19 complete replicons in the nosocomial collection and 77 plasmid contigs in the environmental collection. Comparative genomic analysis showed that many of them had conserved backbones. Plasmid coding sequences corresponding to plasmid specific functions were bioinformatically and functionally analyzed. Replication initiation protein analysis revealed the predominance of the Rep_3 superfamily. The phylogenetic tree constructed from all Acinetobacter Rep_3 superfamily plasmids showed 16 intermingled clades originating from nosocomial and environmental habitats. Phylogenetic analysis of relaxase proteins revealed the presence of a new sub-clade named MOBQAci, composed exclusively of Acinetobacter relaxases. Functional analysis of proteins belonging to this group showed that they behaved differently when mobilized using helper plasmids belonging to different incompatibility groups.Fil: Salto, Ileana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Torres Tejerizo, Gonzalo Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentina. Universitat Bielefeld. Center For Biotechnology; AlemaniaFil: Wibberg, Daniel. Universitat Bielefeld. Center For Biotechnology; AlemaniaFil: Pühler, Alfred. Universitat Bielefeld. Center For Biotechnology; AlemaniaFil: Schlüter, Andreas. Universitat Bielefeld. Center For Biotechnology; AlemaniaFil: Pistorio, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

A blaVIM-2 Plasmid Disseminating in Extensively Drug-Resistant Clinical Pseudomonas aeruginosa and Serratia marcescens Isolates

Infections caused by carbapenem-resistant Enterobacteriaceae isolates are an issue of major global concern (1). Genes coding for metallo-β-lactamases (MβLs) identified in clinical isolates are associated with mobile elements and subject to horizontal genetic transfer (HGT) events (2–6). VIM-2 is present on numerous plasmids, but only pNOR-2000 from Pseudomonas aeruginosa COL-1 from France (7, 8) and pLD209 from Pseudomonas putida LD209 from Argentina (9) have been completely sequenced. Here, we report the complete sequence and characterization of plasmid pDCPR1 harboring a blaVIM-2 gene cassette in a Tn402-type class 1 integron, which was isolated from two extensively drug-resistant strains: P. aeruginosa 802 (from a burn patient at the Hospital Municipal de Quemados, Argentina, 2005) and S. marcescens 68313 (Sanatorio Sagrado Corazón, Argentina, 2012).Fil: Vilacoba, Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Quiroga, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Pistorio, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Famiglietti, Angela María Rosa. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rodriguez, Hernan Bernardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Kovensky, Jaime. Ciudad Autónoma de Buenos Aires. Hospital Municipal de Quemados; ArgentinaFil: Deraspe, Maxime. Université du Québec a Montreal; Canadá. Laval University; CanadáFil: Raymond, Frédéric. Université du Québec a Montreal; Canadá. Laval University; CanadáFil: Roy, Paul H.. Université du Québec a Montreal; Canadá. Laval University; CanadáFil: Centron, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Impact of allergic rhinitis on asthma: effects on bronchodilation testing

A remarkable relationship exists between the upper and lower airways. Bronchial obstruction is a paramount feature of asthma, and its reversibility is considered a main step in asthma diagnosis

Relationship between rhinitis duration and worsening of nasal function

While it is well known that asthma is characterized by airway remodeling, few studies instead have investigated this issue in patients with allergic rhinitis (AR)

The relationship between drive to thinness, conscientiousness and bulimic traits during adolescence: a comparison between younger and older cases in 608 healthy volunteers

Adolescence represents one of the critical transitions in the life span and is characterized by a tremendous pace in growth and change that is second only to that of infancy. Both biological and psychological changes occurring during early adolescence may also influence the definition of subsequent late adolescence or early adulthood physiological or (psycho)-pathological features, including bulimia nervosa (BN) whenever occurring. Therefore, a pre-emptive assessment of suggestive psychological traits, including bulimic ones, during early and late years of adolescence, is recommended and represents the goal of the present study

Cognitive functioning and subjective quality of life in relapsing-remitting multiple sclerosis patients before and after percutaneous transluminal angioplasty: a preliminary report

Multiple sclerosis (MS) is a disease of the nervous system that has profound effects on everyday functioning and quality of life of not only the person who is diagnosed, but also her/his family and acquaintances. Despite this, the uncertainties of the actual etiological basis of MS make it difficult to reach a conclusive statement about the optimal therapeutic management of the disease, which may differ depending on the given case and phase of illness. This has led to an interest in potential novel therapeutic avenues, including percutaneous transluminal angioplasty (PTA). Yet, evidence in support of PTA in the management of MS is scarce and contradictory. The aim of the present study was to provide a preliminary assessment as to whether PTA may impact subjective quality of life and cognitive functioning in severe MS

Development of an HPLC-based oligosaccharide synthesizer

Carbohydrates are the most abundant molecules on Earth. They are involved in a wide range of fundamental biological processes: anti-inflammation, immune response, joint lubrication, cell growth, antigenic determination. Carbohydrates are also held responsible for many damaging cellular processes, such as bacterial and viral infections, development of tumors, etc.. Therefore, the development of effective methods for the synthesis of complex carbohydrates has become a critical area of glycosciences. One challenge that stands out is the stereocontrol in the synthesis of glycosidic bonds, the linkage that serves as the only means to connect simple monosaccharides into complex oligomeric networks. Beyond this, the lack of a simple automated platform, similar to that utilized in the preparation of oligonucleotides and oligopeptides, significantly hampers access to oligosaccharides. The work presented herein addresses both of these limitations of oligosaccharides synthesis: stereocontrol and the lack of automation. The stereocontrolled formation of very challenging betamannosidic linkages has been achieved using a new reaction called Hydrogen-bondmediated Aglycone Delivery (HAD). Automation in Oligosaccharide solid phase synthesis has been accomplished using an AgilentTM HPLC, model 1260 Infinity, that was adapted to the polymer supported synthesis of oligosaccharides. The utility of the HAD reaction and the HPLC-based automated technology has been demonstrated by the synthesis of different oligosaccharide sequences in high stereoselectivities and yields