Vicia faba L. in the Bejaia region of Algeria is nodulated by Rhizobium leguminosarum sv. viciae, Rhizobium laguerreae and two new genospecies

Fifty-eight rhizobial strains were isolated from root nodules of Vicia faba cv. Equina and Vicia faba cv. Minor by the host-trapping method in soils collected from eleven sites in Bejaia, Eastern Algeria. Eleven genotypic groups were distinguished based on the combined PCR/RFLP of 16S rRNA, 16S–23S rRNA intergenic spacer and symbiotic (nodC and nodD-F) genes and further confirmed by multilocus sequence analysis (MLSA) of three housekeeping genes (recA, atpD and rpoB), the 16S rRNA gene and the nodulation genes nodC and nodD. Of the 11 genotypes, 5 were dominant and 2 were the most represented. Most of the strains shared high nodD gene sequence similarity with Rhizobium leguminosarum sv. viciae; their nodC sequences were similar to both Rhizobium leguminosarum and Rhizobium laguerreae. Sequence analyses of the 16S–23S rRNA intergenic spacer showed that all the new strains were phylogenetically related to those described from Vicia sativa and V. faba in several African, European, American and Asian countries, with which they form a group related to Rhizobium leguminosarum. Phylogenetic analysis based on MLSA of 16S rRNA, recA, atpD and rpoB genes allowed the affiliations of strain AM11R to Rhizobium leguminosarum sv. viciae and of strains EB1 and ES8 to Rhizobium laguerreae. In addition, two separate clades with <97% similarity may represent two novel genospecies within the genus Rhizobium.     

Virgibacillus natechei sp. nov., A Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in Southwest of Algeria

A novel, Gram-positive, moderately halophilic bacterium, oxidase- and catalase-positive designated FarD^T was isolated from sediments of a saline lake located in Taghit, 93 km from Bechar, southwest of Algeria. Cells were rod-shaped, endospore forming, and motile. Growth occurred at 15–40 °C (optimum, 35 °C), pH 6.0–12.0 (optimum, 7.0) and in the presence of 1–20 % NaCl (optimum, 10 %). Strain FarD^T used glucose, mannitol, melibiose, d-mannose, and 5 ketogluconate. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, and three phospholipids; MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C_15:0, anteiso C_17:0, C_20:0, and anteiso C_19:0. The DNA G+C content was 42.1 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA gene sequence indicated that strain FarD^T had as its closest relative Virgibacillus salinus (similarity of 96.3 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain FarD^T is proposed as a novel species of the genus Virgibacillus within the order Clostridiales, for which the name V. natechei is proposed. The type strain is FarD^T (=DSM 25609^T = CCUG 62224^T).     

Azithromycin and cough-specific health status in patients with chronic obstructive pulmonary disease and chronic cough: a randomised controlled trial

Background

Macrolides reduce exacerbations in patients with COPD. Their effects on health status has not been assessed as primary outcome and is less clear. This study assessed the effects of prophylactic azithromycin on cough-specific health status in COPD-patients with chronic productive cough.

Methods

In this randomised controlled trial 84 patients met the eligibility criteria: age of ≥40 years, COPD GOLD stage ≥2 and chronic productive cough. The intervention-group (n = 42) received azithromycin 250 mg 3 times a week and the control-group (n = 42) received a placebo. Primary outcome was cough-specific health status at 12 weeks, measured with the Leicester Cough Questionnaire (LCQ). Secondary outcomes included generic and COPD-specific health status and exacerbations. Changes in adverse events and microbiology were monitored.

Results

Mean age of participants was 68 ± 10 years and mean FEV1 was 1.36 ± 0.47 L. The improvement in LCQ total score at 12 weeks was significantly greater with azithromycin (difference 1.3 ± 0.5, 95% CI 0.3;2.3, p = 0.01) and met the minimal clinically important difference. Similar results were found for the domain scores, and COPD-specific and generic health status questionnaires. Other secondary endpoints were non-significant. No imbalances in adverse events were found.

Conclusions

Prophylactic azithromycin improved cough-specific health status in COPD-patients with chronic productive cough to a clinically relevant degree.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01071161","term_id":"NCT01071161"}}NCT01071161     

Studies ON Epimeric-D-asabino-and-D-ribo-tetritol-1-yl-2-phenyl-2 H-1,2,3-triazoles. Synthesis and Anomeric Configuration of 4-(α-and β-D-Erythrofuranosyl)-2-phenyl-2 H-1,2,3-Triazole C-Nucleoside Analogs

Abstract

Treatment of 4-(D-arabino-tetritol-1-yl)-2-phenyl-2 H-1,2,3-triazole (1) with one mole equivalent of tosyl chloride in pyridine solution, afforded the C-nucleoside analogs, 4-(α-D-erythrofuranosyl)-2-phenyl-2 H-1,2,3-triazole (2) in 25% yield, as well as the byproduct 4-(4-chloro-4-deoxy-D-arabino-tetritol-1-yl)-2-phenyl-2 H-1,2,3-triazole(3). Treatment of the epimeric 4-(D-ribo-tetritol-1-yl)-2-phenyl-2 H-1,2,3-triazole(8) with tosyl chloride in pyridine solution afforded the anomeric C-nucleoside analogs, 4-(β-D-erythrofuranosyl)-2-phenyl-2 H-1,2,3-triazole (9) in 23% yield. Similar treatment of 8 with trifluoromethanesulfonyl chloride in pyridine solution afforded 9. The structure and anomeric configuration of these compounds were determined by acylation, NMR, NOE, circular dichroism spectroscopy and mass spectrometry.     

Molecular Architecture of Synaptic Actin Cytoskeleton in Hippocampal Neurons Reveals a Mechanism of Dendritic Spine Morphogenesis

Excitatory synapses in the brain play key roles in learning and memory. The formation and functions of postsynaptic mushroom-shaped structures, dendritic spines, and possibly of presynaptic terminals, rely on actin cytoskeleton remodeling. However, the cytoskeletal architecture of synapses remains unknown hindering the understanding of synapse morphogenesis. Using platinum replica electron microscopy, we characterized the cytoskeletal organization and molecular composition of dendritic spines, their precursors, dendritic filopodia, and presynaptic boutons. A branched actin filament network containing Arp2/3 complex and capping protein was a dominant feature of spine heads and presynaptic boutons. Surprisingly, the spine necks and bases, as well as dendritic filopodia, also contained a network, rather than a bundle, of branched and linear actin filaments that was immunopositive for Arp2/3 complex, capping protein, and myosin II, but not fascin. Thus, a tight actin filament bundle is not necessary for structural support of elongated filopodia-like protrusions. Dynamically, dendritic filopodia emerged from densities in the dendritic shaft, which by electron microscopy contained branched actin network associated with dendritic microtubules. We propose that dendritic spine morphogenesis begins from an actin patch elongating into a dendritic filopodium, which tip subsequently expands via Arp2/3 complex-dependent nucleation and which length is modulated by myosin II-dependent contractility.     

Fine-mapping of the BaMMV, BaYMV-1 and BaYMV-2 resistance of barley (Hordeum vulgare) accession PI1963

Barley yellow mosaic disease caused by the bymoviruses barley mild mosaic virus (BaMMV) and barley yellow mosaic virus (BaYMV) is one of the economically most important diseases of winter barley in Europe. In European barley breeding programmes, resistance is currently due to only two genes—rym4, which is effective against viruses BaMMV and BaYMV-1, and rym5, which is effective against BaYMV-2. Diversification of resistance is therefore an important task. Because the accession PI1963 confers immunity against all European strains of barley yellow mosaic disease and is not allelic to rym5, we have attempted to develop closely linked markers in order to facilitate the efficient introgression of this resistance into adapted germplasm. By means of restriction fragment length polymorphism analysis, we located a gene locus for resistance to BaMMV, BaYMV-1 and BaYMV-2 of PI1963 on chromosome 4HL using a mapping population (W757) comprising 57 doubled haploid (DH) lines. Subsequent tests for allelism indicated that the BaMMV resistance gene in PI1963 is allelic to rym11. Two DH populations, IPK1 and IPK2, comprising 191 and 161 DH lines, respectively, were derived from the initial mapping population W757 and used for further analysis. As random amplified polymorphic DNA development did not facilitate the identification of more closely linked markers, simple sequence repeat (SSR) analyses were conducted. For population IPK1, the closest SSRs detected were Bmac181 and Bmag353, which flank the gene at 2.1 cM and 2.7 cM, respectively. For the IPK2 population, the SSR markers HVM3 and Bmag353 are located proximally at 2.5 cM and distally at 8.2 cM, respectively. In order to develop markers more tightly linked to rym11, a targeted amplified fragment length polymorphism (AFLP) marker identification approach was adopted using bulks comprising lines carrying recombination events proximal and distal to the target interval. Using this approach we identified six AFLP markers closely linked to rym11, with the two markers, E56M32 and E49M33, co-segregating with rym11 in both populations. The SSRs and AFLPs identified in this study represent useful tools for marker-assisted selection.     

Cardiac mitochondrial connexin 43 regulates apoptosis

Connexin 43 (Cx43) is thought to be present largely in the plasma membrane and its function solely to provide low resistance electrical connection between myocytes. A recent report suggested the presence of Cx43 in the mitochondria as well. We confirmed the presence of Cx43 in the mitochondria isolated from adult rat ventricles with the Cx43 immunoreactivity fractionating to the outer mitochondrial membrane. Mitochondrial Cx43 is mostly phosphorylated only detected by a phospho-specific antibody. Using a Ca2+ -sensitive electrode and Western blot, we showed that the gap junction inhibitors 18-beta-glycyrrhetinic acid (beta-GA), oleamide, and heptanol all induced concomitant release of Ca2+ and cytochrome C in isolated mitochondria whereas the inactive analog 18-beta-glycyrrhizic acid failed to do so. In low density neonatal myocyte culture with no appreciable cell-cell contacts, beta-GA induced apoptosis as assessed by TUNEL staining. Our results suggest a novel role of Cx43 as a regulator of mitochondrial physiology and myocyte apoptosis.     

Nerve growth factor promotes reorganization of the axonal microtubule array at sites of axon collateral branching

The localized debundling of the axonal microtubule array and the entry of microtubules into axonal filopodia are two defining features of collateral branching. We report that nerve growth factor (NGF), a branch‐inducing signal, increases the frequency of microtubule debundling along the axon shaft of chicken embryonic sensory neurons. Sites of debundling correlate strongly with the localized targeting of microtubules into filopodia. Platinum replica electron microscopy suggests physical interactions between debundled microtubules and axonal actin filaments. However, as evidenced by depolymerization of actin filaments and inhibition of myosin II, actomyosin force generation does not promote debundling. In contrast, loss of actin filaments or inhibition of myosin II activity promotes debundling, indicating that axonal actomyosin forces suppress debundling. MAP1B is a microtubule associated protein that represses axon branching. Following treatment with NGF, microtubules penetrating filopodia during the early stages of branching exhibited lower levels of associated MAP1B. NGF increased and decreased the levels of MAP1B phosphorylated at a GSK‐3β site (pMAP1B) along the axon shaft and within axonal filopodia, respectively. The levels of MAP1B and pMAP1B were not altered at sites of debundling, relative to the rest of the axon. Unlike the previously determined effects of NGF on the axonal actin cytoskeleton, the effects of NGF on microtubule debundling were not affected by inhibition of protein synthesis. Collectively, these data indicate that NGF promotes localized axonal microtubule debundling, that actomyosin forces antagonize microtubule debundling, and that NGF regulates pMAP1B in axonal filopodia during the early stages of collateral branch formation. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1441–1461, 2015