Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Med. intensiva (Madr., Ed. impr.) ; 40(5): 273-279, jun.-jul. 2016. graf, tab
Article in Spanish | IBECS | ID: ibc-153935

ABSTRACT

OBJETIVO: Estudiar si la ampliación, a festivos y fines de semana, del protocolo de detección proactiva precoz de gravedad en el hospital y actuación de intensivistas en planta convencional y urgencias (actividad «UCI sin paredes») se asocia a una reducción en la mortalidad de los pacientes ingresados en UCI en esos días. DISEÑO: Estudio cuasi experimental before-after. ÁMBITO: Hospital de nivel 2 con 210 camas en funcionamiento y UCI polivalente con 8 camas. PACIENTES O PARTICIPANTES: En el grupo control, donde no se realiza la actividad «UCI sin paredes» los fines de semana ni festivos, se incluyeron los pacientes ingresados en la UCI esos días del 1 de enero de 2010 al 30 de abril de 2013. En el grupo intervención se amplió la actividad «UCI sin paredes» a los fines de semana y festivos y se incluyeron los pacientes ingresados esos días del 1 de mayo de 2013 al 31 de octubre de 2014. Se excluyeron los pacientes procedentes de quirófano tras una cirugía programada. Variables de interés: Se analizaron las variables demográficas (edad, sexo), la procedencia (urgencias, planta de hospitalización, quirófano), el tipo de paciente (médico, quirúrgico), el motivo de ingreso, las comorbilidades y el SAPS 3 como puntuación de gravedad al ingreso, estancia en UCI y hospitalaria, además de la mortalidad en la UCI y en el hospital. RESULTADOS: Se incluyeron en el grupo control 389 pacientes, y 161 en el grupo intervención. No se encontraron diferencias entre ambos grupos, salvo en la comorbilidad cardiovascular (un 49% en el grupo control frente a un 33% en el grupo intervención; p < 0,001), en la gravedad al ingreso medida mediante el SAPS 3 (mediana de 52 [percentiles 25-75: 42-63] en el grupo control frente a 48 [percentiles 25-75: 40-56] en el grupo intervención; p= 0,008) y en la mortalidad en UCI, que fue de un 11% en el grupo control (IC 95% 8 a 14) frente al 3% (IC 95% 1 a 7) en el grupo intervención (p = 0,003). En el análisis multivariable, los 2 únicos factores asociados con la mortalidad en UCI fueron: SAPS 3 (OR 1,08; IC 95% 1,06-1,11) y el pertenecer al grupo intervención (OR 0,33; IC 95% 0,12-0,89). CONCLUSIONES: La ampliación de la actividad «UCI sin paredes» a los fines de semana y festivos conlleva un descenso en la mortalidad en la UCI


OBJECTIVE: To determine whether extension to holidays and weekends of the protocol for the early proactive detection of severity in hospital («ICU without walls» project) results in decreased mortality among patients admitted to the ICU during those days. DESIGN: A quasi-experimental before-after study was carried out. SETTING: A level 2 hospital with 210 beds and a polyvalent ICU with 8 beds. PATIENTS OR PARTICIPANTS: The control group involved no «ICU without walls» activity on holidays or weekends and included those patients admitted to the ICU on those days between 1 January 2010 and 30 April 2013. The intervention group in turn extended the «ICU without walls» activity to holidays and weekends, and included those patients admitted on those days between 1 May 2013 and 31 October 2014. Patients arriving from the operating room after scheduled surgery were excluded. Variables of interest: An analysis was made of the demographic variables (age, gender), origin (emergency room, hospital ward, operating room), type of patient (medical, surgical), reason for admission, comorbidities and SAPS 3 score as a measure of severity upon admission, stay in the ICU and in hospital, and mortality in the ICU and in hospital. RESULTS: A total of 389 and 161 patients were included in the control group and intervention group, respectively. There were no differences between the 2 groups except as regards cardiovascular comorbidity (49% in the control group versus 33% in the intervention group; P < .001), severity upon admission (median SAPS 3 score 52 [percentiles 25-75: 42-63) in the control group versus 48 [percentiles 25-75: 40-56] in the intervention group; P = .008) and mortality in the ICU (11% in the control group [95% CI 8-14] versus 3% [95% CI 1-7] in the intervention group; P = .003). In the multivariate analysis, the only 2 factors associated to mortality in the ICU were the SAPS 3 score (OR 1.08; 95% CI 1.06-1.11) and inclusion in the intervention group (OR 0.33; 95% CI 0.12-0.89). CONCLUSIONS: Extension of the «ICU without walls» activity to holidays and weekends results in a decrease in mortality in the ICU


Subject(s)
Humans , Critical Illness/mortality , Severity of Illness Index , Decision Support Techniques , Critical Care/organization & administration , Intensive Care Units/organization & administration , Early Diagnosis , Evaluation of the Efficacy-Effectiveness of Interventions , Case-Control Studies
2.
Med. intensiva (Madr., Ed. impr.) ; 40(1): 26-32, ene.-feb. 2016. ^ilus, tab, graf
Article in Spanish | IBECS | ID: ibc-149337

ABSTRACT

OBJETIVO: Evaluar la repercusión del momento de ingreso en UCI sobre el pronóstico de los pacientes. DISEÑO: Estudio de cohorte prospectivo, observacional y no intervencionista. Se consideró on-hours el turno de mañana y tarde de los días laborables y off-hours el resto de los turnos. ÁMBITO: Hospital de nivel 2 con 210 camas en funcionamiento y UCI polivalente con 8 camas. PACIENTES O PARTICIPANTES: Todos los pacientes que ingresaron en la UCI durante 3 años, de enero de 2010 a diciembre de 2012, excluyendo aquellos pacientes procedentes de quirófano tras una cirugía programada. Los pacientes se estratificaron en 2 grupos en función de que el momento de ingreso fuera on-hours u off-hours. Intervenciones: Estudio no intervencionista. VARIABLES DE INTERÉS: Se analizaron las variables demográficas (edad, sexo), la procedencia (urgencias, planta de hospitalización, quirófano), el tipo de paciente (médico, quirúrgico), las comorbilidades y el SAPS 3 como puntuación de gravedad al ingreso, estancia en UCI y hospitalaria, además de mortalidad en la UCI y en el hospital. RESULTADOS: Se incluyeron 504 pacientes en el grupo on-hours y 602 en el grupo off-hours. En el análisis multivariable los factores asociados de forma independiente con la mortalidad hospitalaria fueron SAPS 3 (OR 1,10; IC 95% 1,08-1,12) y grupo off-hours (OR 2,00; IC 95% 1,20-3,33). En un análisis de subgrupos del grupo off-hours el ingreso de los pacientes en fin de semana o festivo frente a las noches de los días de diario se asoció de forma independiente con la mortalidad hospitalaria (OR 2,30; IC 95% 1,23-4,30). CONCLUSIONES: Ingresar en el grupo off-hours se asocia de forma independiente con la mortalidad. El ingreso en festivo se asocia de forma independiente con la mortalidad, independientemente del turno en que se produzca el ingreso los días de diario


OBJECTIVE: To assess the repercussion of the timing of admission to the ICU upon patient prognosis. DESIGN: A prospective, observational, non-interventional cohort study was carried out. Scope: A second level hospital with 210 operational beds and a general ICU with 8 operational beds. PATIENTS OR PARTICIPANTS: The study comprised all patients admitted to the ICU during 3 years (January 2010 to December 2012), excluding those subjects admitted from the operating room after scheduled surgery. The patients were divided into 2 groups according to the timing of admission (on-hours or off-hours). INTERVENTIONS: Non-interventional study. VARIABLES OF INTEREST: An analysis was made of demographic variables (age, sex), origin (emergency room, hospital ward, operating room), comorbidities and SAPS 3 as severity score upon admission, length of stay in the ICU and hospital ward, and ICU and hospital mortality. RESULTS: A total of 504 patients were included in the on-hours group, versus 602 in the off-hours group. Multivariate analysis showed the factors independently associated to hospital mortality to be SAPS 3 (OR 1.10; 95% CI 1.08-1.12), and off-hours admission (OR 2.00; 95% CI 1.20-3.33). In a subgroup analysis of the off-hours group, the admission of patients on weekends or non-working days compared to daily night shifts was found to be independently associated to hospital mortality (OR 2.30; 95% CI 1.23-4.30). CONCLUSIONS: Admission to the ICU in off-hours is independently associated to patient mortality, which is also higher in patients admitted on weekends and non-working days compared to the daily night shifts


Subject(s)
Humans , Intensive Care Units/statistics & numerical data , Health Services Statistics , Prognosis , Risk Factors , Prospective Studies , Inpatients/statistics & numerical data
3.
Med Intensiva ; 40(5): 273-9, 2016.
Article in English, Spanish | MEDLINE | ID: mdl-26547480

ABSTRACT

OBJECTIVE: To determine whether extension to holidays and weekends of the protocol for the early proactive detection of severity in hospital ("ICU without walls" project) results in decreased mortality among patients admitted to the ICU during those days. DESIGN: A quasi-experimental before-after study was carried out. SETTING: A level 2 hospital with 210 beds and a polyvalent ICU with 8 beds. PATIENTS OR PARTICIPANTS: The control group involved no "ICU without walls" activity on holidays or weekends and included those patients admitted to the ICU on those days between 1 January 2010 and 30 April 2013. The intervention group in turn extended the "ICU without walls" activity to holidays and weekends, and included those patients admitted on those days between 1 May 2013 and 31 October 2014. Patients arriving from the operating room after scheduled surgery were excluded. VARIABLES OF INTEREST: An analysis was made of the demographic variables (age, gender), origin (emergency room, hospital ward, operating room), type of patient (medical, surgical), reason for admission, comorbidities and SAPS 3 score as a measure of severity upon admission, stay in the ICU and in hospital, and mortality in the ICU and in hospital. RESULTS: A total of 389 and 161 patients were included in the control group and intervention group, respectively. There were no differences between the 2 groups except as regards cardiovascular comorbidity (49% in the control group versus 33% in the intervention group; P<.001), severity upon admission (median SAPS 3 score 52 [percentiles 25-75: 42-63) in the control group versus 48 [percentiles 25-75: 40-56] in the intervention group; P=.008) and mortality in the ICU (11% in the control group [95% CI 8-14] versus 3% [95% CI 1-7] in the intervention group; P=.003). In the multivariate analysis, the only 2 factors associated to mortality in the ICU were the SAPS 3 score (OR 1.08; 95% CI 1.06-1.11) and inclusion in the intervention group (OR 0.33; 95% CI 0.12-0.89). CONCLUSIONS: Extension of the "ICU without walls" activity to holidays and weekends results in a decrease in mortality in the ICU.


Subject(s)
Holidays , Hospital Mortality , Intensive Care Units/organization & administration , Aged , Appointments and Schedules , Controlled Before-After Studies , Decision Support Techniques , Diagnosis-Related Groups , Early Diagnosis , Female , Hospital Bed Capacity , Hospital Mortality/trends , Humans , Length of Stay/statistics & numerical data , Male , Middle Aged , Organ Dysfunction Scores , Patient Admission , Patient Care Team , Prognosis , Risk Factors , Secondary Care Centers , Simplified Acute Physiology Score , Spain , Treatment Outcome
4.
Med Intensiva ; 40(1): 26-32, 2016.
Article in English, Spanish | MEDLINE | ID: mdl-25682488

ABSTRACT

OBJECTIVE: To assess the repercussion of the timing of admission to the ICU upon patient prognosis. DESIGN: A prospective, observational, non-interventional cohort study was carried out. SCOPE: A second level hospital with 210 operational beds and a general ICU with 8 operational beds. PATIENTS OR PARTICIPANTS: The study comprised all patients admitted to the ICU during 3 years (January 2010 to December 2012), excluding those subjects admitted from the operating room after scheduled surgery. The patients were divided into 2 groups according to the timing of admission (on-hours or off-hours). INTERVENTIONS: Non-interventional study. VARIABLES OF INTEREST: An analysis was made of demographic variables (age, sex), origin (emergency room, hospital ward, operating room), comorbidities and SAPS 3 as severity score upon admission, length of stay in the ICU and hospital ward, and ICU and hospital mortality. RESULTS: A total of 504 patients were included in the on-hours group, versus 602 in the off-hours group. Multivariate analysis showed the factors independently associated to hospital mortality to be SAPS 3 (OR 1.10; 95% CI 1.08-1.12), and off-hours admission (OR 2.00; 95% CI 1.20-3.33). In a subgroup analysis of the off-hours group, the admission of patients on weekends or non-working days compared to daily night shifts was found to be independently associated to hospital mortality (OR 2.30; 95% CI 1.23-4.30). CONCLUSIONS: Admission to the ICU in off-hours is independently associated to patient mortality, which is also higher in patients admitted on weekends and non-working days compared to the daily night shifts.


Subject(s)
Hospital Mortality , Intensive Care Units , Patient Admission , Humans , Length of Stay , Personnel Staffing and Scheduling , Prognosis , Prospective Studies , Time Factors
5.
Nat Genet ; 22(3): 271-5, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10391215

ABSTRACT

Arabidopsis thaliana is a small flowering plant that serves as the major model system in plant molecular genetics. The efforts of many scientists have produced genetic maps that provide extensive coverage of the genome (http://genome-www. stanford.edu/Arabidopsis/maps.html). Recently, detailed YAC, BAC, P1 and cosmid-based physical maps (that is, representations of genomic regions as sets of overlapping clones of corresponding libraries) have been established that extend over wide genomic areas ranging from several hundreds of kilobases to entire chromosomes. These maps provide an entry to gain deeper insight into the A. thaliana genome structure. A. thaliana has been chosen as the subject of the first large-scale project intended to determine the full genome sequence of a plant. This sequencing project, together with the increasing interest in map-based gene cloning, has highlighted the requirement for a complete and accurate physical map of this plant species. To supply the scientific community with a high-quality resource, we present here a complete physical map of A. thaliana using essentially the IGF BAC library. The map consists of 27 contigs that cover the entire genome, except for the presumptive centromeric regions, nucleolar organization regions (NOR) and telomeric areas. This is the first reported map of a complex organism based entirely on BAC clones and it represents the most homogeneous and complete physical map established to date for any plant genome. Furthermore, the analysis performed here serves as a model for an efficient physical mapping procedure using BAC clones that can be applied to other complex genomes.


Subject(s)
Arabidopsis/genetics , Genome, Plant , Physical Chromosome Mapping , Chromosomes, Bacterial/genetics , Cloning, Molecular , Contig Mapping , Databases, Factual , Gene Library , Genetic Markers
6.
Mol Gen Genet ; 258(5): 562-70, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9669340

ABSTRACT

A bacterial artificial chromosome (BAC) library has been established for Arabidopsis thaliana (ecotype Col-0) covering about seven haploid nuclear genome equivalents. This library, called the Institut für Genbiologische Forschung (IGF) BAC library, consists of 10,752 recombinant clones carrying inserts (generated by partial EcoRI digestion) of an average size of about 100 kb in a modified BAC vector, pBeloBAC-Kan. Hybridization with organellar DNA and nuclear repetitive DNA elements revealed the presence of 1.1% clones with mitochondrial DNA, 0.2% clones with plastid DNA, 3.2% clones with the 180 bp paracentromeric repeat, 1.6% clones with 5S rDNA, and 10.8% clones with the 18S-25S rDNA repeat. With its extensive genome coverage, its rather uniformly sized inserts (80 kb < 85% < 120 kb) and low contamination with organellar DNA, this library provides an excellent resource for A. thaliana genomic mapping, map-based gene cloning, and genome sequencing.


Subject(s)
Arabidopsis/genetics , Chromosomes, Bacterial , Gene Library , Genome, Plant , Cloning, Molecular , DNA, Mitochondrial/genetics , DNA, Plant/chemistry , DNA, Plant/genetics , Molecular Weight , Plastids/genetics , Polymorphism, Restriction Fragment Length , Repetitive Sequences, Nucleic Acid/genetics
7.
Plant J ; 16(3): 377-84, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9881158

ABSTRACT

In order to generate a physical map of the Arabidopsis thaliana genome based on bacterial artificial chromosome clones (BACs), an iterative high throughput hybridisation strategy was applied and its efficiency was evaluated. Thus, probes generated from both ends of 500 BAC clones selected from the Arabidopsis-IGF-BAC library were hybridised to the entire library gridded on high density filters. The 1000 hybridisation reactions identified 4496 clones (41.8% of the complete library, or 50.3% if organellar, centromeric, and ribosomal DNA carrying clones are excluded) which were assembled into a minimum of 220 contigs. These results demonstrate the viability of the applied 'double-end clone-limited/sampling without replacement' hybridisation strategy for the generation of a high resolution physical map, and provide a highly useful resource for map-based gene cloning approaches and further genome analysis.


Subject(s)
Arabidopsis/genetics , Genome, Plant , Physical Chromosome Mapping/methods , Chromosomes, Bacterial
8.
Plant J ; 7(6): 1015-20, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7599644

ABSTRACT

The mitochondrial ADP/ATP translocator, also called adenine nucleotide translocase (ANT), is synthesized in plants with an N-terminal extension which is cleaved upon import into mitochondria. In contrast, the homologous proteins of mammals or fungi do not contain such a transient amino terminal presequence. To investigate whether the N-terminal extension is needed for correct intracellular sorting in vivo, translational fusions were constructed of the translocator cDNA--with and without presequence--with the beta-glucuronidase (gus) reporter gene. The distribution of reporter enzymatic activity in the subcellular compartments of transgenic plants and transformed yeast cells was subsequently analysed. The results show that: (i) the plant translocator presequence is not necessary for the correct localization of the ANT to the mitochondria; (ii) the mitochondrial targeting information contained in the mature part of the protein is sufficient to overcome, to some extent, the presence of plastid transit peptides; and (iii) the presequence alone is not able to target a passenger protein to mitochondria in vivo.


Subject(s)
Mitochondria/metabolism , Mitochondrial ADP, ATP Translocases/metabolism , Protein Sorting Signals/metabolism , Solanum tuberosum/metabolism , Base Sequence , DNA, Plant , Glucuronidase/genetics , Mitochondrial ADP, ATP Translocases/genetics , Molecular Sequence Data , Plants, Genetically Modified , Protein Sorting Signals/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Solanum tuberosum/genetics
9.
Plant Mol Biol ; 25(2): 271-81, 1994 May.
Article in English | MEDLINE | ID: mdl-8018875

ABSTRACT

The mitochondrial iron-sulfur protein (also termed Rieske iron-sulfur protein) of cytochrome c reductase was purified from potato tubers and identified with heterologous antibodies. The sequences of the N-terminus of this 25 kDa protein and of an internal peptide were determined to design oligonucleotide mixtures for screening a cDNA library. One class of cDNA clones containing an open reading frame of 265 amino acids was isolated. The encoded protein contains the peptide sequences of the 25 kDa protein and shares about 50% sequence identity with the Rieske iron-sulfur proteins from fungi and around 43% with those from mammals. In vitro transcription and translation of the cDNA reveals that the iron-sulfur protein is made as a larger precursor of 30 kDa which is processed by the cytochrome c reductase/processing peptidase complex from potato. The processing product obtained after in vitro processing has the same size as the mature protein imported into isolated mitochondria. The presequence, which targets the protein to the organelle, is 53 amino acids long and has molecular features different from those found in presequences of fungal iron-sulfur proteins, which are processed in two steps. Our results indicate that, unlike in yeast and Neurospora, the presequence of the iron-sulfur protein from potato is removed by a single processing enzyme in one step.


Subject(s)
Electron Transport Complex III , Iron-Sulfur Proteins/metabolism , Mitochondria/chemistry , Solanum tuberosum/chemistry , Amino Acid Sequence , Animals , Base Sequence , Biological Transport , Cattle , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , Genes, Plant , Humans , Iron-Sulfur Proteins/chemistry , Iron-Sulfur Proteins/genetics , Iron-Sulfur Proteins/isolation & purification , Mitochondria/metabolism , Molecular Sequence Data , Neurospora/metabolism , Neurospora/ultrastructure , Protein Processing, Post-Translational , Solanum tuberosum/genetics , Solanum tuberosum/metabolism , Solanum tuberosum/ultrastructure , Transcription, Genetic , Yeasts/chemistry , Yeasts/metabolism
10.
Mol Gen Genet ; 236(1): 1-7, 1992 Dec.
Article in English | MEDLINE | ID: mdl-1494341

ABSTRACT

The loxP-Cre site-specific recombination system of phage P1 was used to develop a novel strategy to construct cointegrate vectors for Agrobacterium-mediated plant transformation. A pTi disarmed helper plasmid (pAL1166) was constructed by replacing the oncogenic T-DNA by a loxP sequence and a spectinomycin resistance marker in the octopine-type pTiB6 plasmid. The cre gene was cloned into an unstable incP plasmid. A third plasmid, which did not replicate in Agrobacterium and contained another loxP sequence together with a kanamycin resistance marker, was used to test the system. Electroporation of this third plasmid into an Agrobacterium strain harbouring both pAL1166 and the Cre-encoding plasmid resulted in kanamycin-resistant cells containing a cointegrate between pAL1166 and the incoming plasmid. Cointegration occurred by Cre-mediated recombination at the loxP sites, and the cointegrate was stabilized in the Agrobacterium cells by the loss of the Cre-encoding plasmid shortly after the recombination event had taken place.


Subject(s)
Genetic Vectors , Integrases , Plants/genetics , Rhizobium/genetics , Transformation, Genetic , Viral Proteins , Bacteriophage P1/genetics , Base Sequence , DNA Nucleotidyltransferases/metabolism , DNA, Single-Stranded , Molecular Sequence Data , Plasmids , Rec A Recombinases/genetics , Recombination, Genetic
11.
Plant Mol Biol ; 19(6): 1019-30, 1992 Sep.
Article in English | MEDLINE | ID: mdl-1511127

ABSTRACT

Different factors involved in the early steps of the T-DNA transfer process were studied by using a beta-glucuronidase gene (gusA) as a reporter in Nicotiana glauca leaf disc transformation experiments. The levels of transient expression of the gusA gene in leaf discs infected with several strains or vir mutants correlated well with their virulence phenotype, except for virC mutants. The rate of T-DNA transfer was shown to be stimulated in the case of non-oncogenic strains by the co-transfer of small amounts of oncogenic genes. It was found that the location of the T-DNA in the Agrobacterium genome affected the T-DNA transfer rate especially in virC mutants. The virC mutants transferred the gusA-containing T-DNA located on a binary vector more efficiently than the oncogenic T-DNA of the Ti plasmid. Although wild-type strains induced high levels of gusA expression early after infection, the gusA expression appeared to be lost late after infection in the infected leaf discs. In contrast, in leaf discs infected by virC mutants the level of gusA expression increased steadily in time. A model explaining these results is presented.


Subject(s)
Agrobacterium tumefaciens/genetics , Nicotiana/genetics , Plants, Toxic , Plasmids , Transformation, Genetic , Agrobacterium tumefaciens/pathogenicity , Kinetics , Mutation , Virulence/genetics
13.
Plasmid ; 23(3): 201-15, 1990 May.
Article in English | MEDLINE | ID: mdl-2217572

ABSTRACT

The DNA region essential for replication and stability of a native plasmid (pTM5) from Rhizobium sp. (Hedysarum) has been identified and isolated within a 5.4-kb PstI restriction fragment. The isolation of this region was accomplished by cloning endonuclease-restricted pTM5 DNA into a ColE1-type replicon and selecting the recombinant plasmids containing the pTM5 replicator (pTM5 derivative plasmids) by their ability to replicate in Rhizobium. DNA homology studies revealed that pTM5-like replicons are present in cryptic plasmids from some Rhizobium sp. (Hedysarum) strains but not in plasmids from strains of other Rhizobium species or Agrobacterium tumefaciens. The pTM5 derivative plasmids were able to replicate in Escherichia coli and A. tumefaciens and in a wide range of Rhizobium species. On the basis of stability assays in the absence of antibiotic selective pressure, the pTM5 derivative plasmids were shown to be highly stable in both free-living and symbiotic cells of Rhizobium sp. (Hedysarum). The stability of these plasmids in other species of Rhizobium and in A. tumefaciens varied depending on the host and on the plasmid. Most pTM5 derivative plasmids tested showed significantly higher symbiotic stability than RK2 derivative plasmids pRK290 and pAL618 in Rhizobium sp. (Hedysarum), R. meliloti, and R. leguminosarum by. phaseoli. Consequently, we consider that the constructed pTM5 derivative plasmids are potentially useful as cloning vectors for Rhizobiaceae.


Subject(s)
Cloning, Molecular/methods , DNA Replication , DNA, Bacterial/genetics , Genetic Vectors , Plasmids , Replicon , Rhizobiaceae/genetics , Rhizobium/genetics , DNA, Bacterial/isolation & purification , Restriction Mapping
14.
Appl Environ Microbiol ; 54(5): 1262-7, 1988 May.
Article in English | MEDLINE | ID: mdl-16347636

ABSTRACT

Forty-five Rhizobium strains nodulating sulla (Hedysarum coronarium L.), isolated from plants grown in different sites in Menorca Island and southern Spain, were examined for plasmid content and the location and organization of nif (nitrogen fixation) and nod (nodulation) sequences. A great diversity in both number and size of the plasmids was observed in this native population of strains, which could be distributed among 19 different groups according to their plasmid profiles. No correlation was found between plasmid profile and geographical origin of the strains. In each strain a single plasmid ranging from 187 to 349 megadaltons hybridized to Rhizobium meliloti nifHD and nodD DNA, and in three strains the spontaneous loss of this plasmid resulted in the loss of the nodulation capacity. In addition to the symbiotic plasmid, 18 different cryptic plasmids were identified. A characteristic cryptic plasmid of >1,000 megadaltons was present in all strains. Total DNA hybridization experiments, with nifHD and portions of nodC and nodD genes (coding for common nodulation functions) from R. meliloti as probes, demonstrated that both the sequence and organization of nif and common nod genes were highly conserved within rhizobia nodulating sulla. Evidence for reiteration of nodD sequences and for linkage of nodC to at least one copy of nodD was obtained for all the strains examined. From these results we conclude that Rhizobium strains nodulating sulla are a homogeneous group of symbiotic bacteria that are closely related to the classical fast-growing group of rhizobia.

15.
J Bacteriol ; 169(11): 4929-34, 1987 Nov.
Article in English | MEDLINE | ID: mdl-2822654

ABSTRACT

A gene library of genomic DNA from the hydrogen uptake (Hup)-positive strain 128C53 of Rhizobium leguminosarum was constructed by using the broad-host-range mobilizable cosmid vector pLAFR1. The resulting recombinant cosmids contained insert DNA averaging 21 kilobase pairs (kb) in length. Two clones from the above gene library were identified by colony hybridization with DNA sequences from plasmid pHU1 containing hup genes of Bradyhizobium japonicum. The corresponding recombinant cosmids, pAL618 and pAL704, were isolated, and a region of about 28 kb containing the sequences homologous to B. japonicum hup-specific DNA was physically mapped. Further hybridization analysis with three fragments from pHU1 (5.9-kb HindIII, 2.9-kb EcoRI, and 5.0-kb EcoRI) showed that the overall arrangement of the R. leguminosarum hup-specific region closely parallels that of B. japonicum. The presence of functional hup genes within the isolated cosmid DNA was demonstrated by site-directed Tn5 mutagenesis of the 128C53 genome and analysis of the Hup phenotype of the Tn5 insertion strains in symbiosis with peas. Transposon Tn5 insertions at six different sites spanning 11 kb of pAL618 completely suppressed the hydrogenase activity of the pea bacteroids.


Subject(s)
Cloning, Molecular , Genes, Bacterial , Hydrogen/metabolism , Rhizobium/genetics , Cosmids , DNA Restriction Enzymes , Escherichia coli/genetics , Genetic Vectors , Genotype , Nucleic Acid Hybridization , Plasmids , Rhizobium/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...