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Management of patients during and after exacerbations of chronic obstructive pulmonary disease: the role of primary care physicians

Current treatments have failed to stem the continuing rise in health care resource use and fatalities associated with exacerbations of chronic obstructive pulmonary disease (COPD). Reduction of severity and prevention of new exacerbations are therefore important in disease management, especially for patients with frequent exacerbations. Acute exacerbation treatment includes short-acting bronchodilators, systemic corticosteroids, and antibiotics if bacterial infections are present. Oxygen and/or ventilatory support may be necessary for life-threatening conditions. Rising health care costs have provided added impetus to find novel therapeutic approaches in the primary care setting to prevent and rapidly treat exacerbations before hospitalization is required. Proactive interventions may include risk reduction measures (eg, smoking cessation and vaccinations) to reduce triggers and supplemental pulmonary rehabilitation to prevent or delay exacerbation recurrence. Long-term treatment strategies should include individualized management, addressing coexisting nonpulmonary conditions, and the use of maintenance pharmacotherapies, eg, long-acting bronchodilators as monotherapy or in combination with inhaled corticosteroids to reduce exacerbations. Self-management plans that help patients recognize their symptoms and promptly access treatments have the potential to prevent exacerbations from reaching the stage that requires hospitalization

Global landscape of phenazine biosynthesis and biodegradation reveals species-specific colonization patterns in agricultural soils and crop microbiomes

Phenazines are natural bacterial antibiotics that can protect crops from disease. However, for most crops it is unknown which producers and specific phenazines are ecologically relevant, and whether phenazine biodegradation can counter their effects. To better understand their ecology, we developed and environmentally-validated a quantitative metagenomic approach to mine for phenazine biosynthesis and biodegradation genes, applying it to >800 soil and plant-associated shotgun-metagenomes. We discover novel producer-crop associations and demonstrate that phenazine biosynthesis is prevalent across habitats and preferentially enriched in rhizospheres, whereas biodegrading bacteria are rare. We validate an association between maize and Dyella japonica, a putative producer abundant in crop microbiomes. D. japonica upregulates phenazine biosynthesis during phosphate limitation and robustly colonizes maize seedling roots. This work provides a global picture of phenazines in natural environments and highlights plant-microbe associations of agricultural potential. Our metagenomic approach may be extended to other metabolites and functional traits in diverse ecosystems

Mobile genetic elements in the genome of the beneficial rhizobacterium Pseudomonas fluorescens Pf-5

<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas fluorescens </it>Pf-5 is a plant-associated bacterium that inhabits the rhizosphere of a wide variety of plant species and and produces secondary metabolites suppressive of fungal and oomycete plant pathogens. The Pf-5 genome is rich in features consistent with its commensal lifestyle, and its sequence has revealed attributes associated with the strain's ability to compete and survive in the dynamic and microbiologically complex rhizosphere habitat. In this study, we analyzed mobile genetic elements of the Pf-5 genome in an effort to identify determinants that might contribute to Pf-5's ability to adapt to changing environmental conditions and/or colonize new ecological niches.</p> <p>Results</p> <p>Sequence analyses revealed that the genome of Pf-5 is devoid of transposons and IS elements and that mobile genetic elements (MGEs) are represented by prophages and genomic islands that collectively span over 260 kb. The prophages include an F-pyocin-like prophage 01, a chimeric prophage 03, a lambdoid prophage 06, and decaying prophages 02, 04 and 05 with reduced size and/or complexity. The genomic islands are represented by a 115-kb integrative conjugative element (ICE) PFGI-1, which shares plasmid replication, recombination, and conjugative transfer genes with those from ICEs found in other <it>Pseudomonas </it>spp., and PFGI-2, which resembles a portion of pathogenicity islands in the genomes of the plant pathogens <it>Pseudomonas syringae </it>and <it>P. viridiflava</it>. Almost all of the MGEs in the Pf-5 genome are associated with phage-like integrase genes and are integrated into tRNA genes.</p> <p>Conclusion</p> <p>Comparative analyses reveal that MGEs found in Pf-5 are subject to extensive recombination and have evolved in part via exchange of genetic material with other <it>Pseudomonas </it>spp. having commensal or pathogenic relationships with plants and animals. Although prophages and genomic islands from Pf-5 exhibit similarity to MGEs found in other <it>Pseudomonas </it>spp., they also carry a number of putative niche-specific genes that could affect the survival of <it>P. fluorescens </it>Pf-5 in natural habitats. Most notable are a ~35-kb segment of "cargo" genes in genomic island PFGI-1 and bacteriocin genes associated with prophages 1 and 4.</p

A proteomic analysis of Psychrobacter articus 273-4 adaptation to low temperature and salinity using a 2-D liquid mapping approach

Psychrobacter 273-4 was isolated from a 20 000–40 000–year-old Siberian permafrost core, which is characterized by low temperature, low water activity, and high salinity. To explore how 273-4 survives in the permafrost environment, proteins in four 273-4 samples cultured at 4 and 22°C in media with and without 5% 14sodium chloride were profiled and comparatively studied using 2-D HPLC and MS. The method used herein involved fractionation via a pH gradient using chromatofocusing followed by nonporous silica 14(NPS) RP-HPLC and on-line electrospray mass mapping. It was observed that 33 14proteins were involved in the adaptation to low temperature in the cells grown in the nonsaline media while there were only 14 proteins involved in the saline media. There were 45 14proteins observed differentially expressed in response to salt at 22°C while there were 22 14proteins at 4°C. In addition, 5% 14NaCl and 4°C showed a combination effect on protein expression. A total of 56 14proteins involved in the adaptation to low temperature and salt were identified using MS and database searching. The differentially expressed proteins were classified into different functional categories where the response of the regulation system to stress appears to be very elaborate. The evidence shows that the adaptation of 273-4 is based primarily on the control of translation and transcription, the synthesis of proteins (chaperones) to facilitate RNA and protein folding, and the regulation of metabolic pathways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55939/1/467_ftp.pd

Chronotropic incompetence predicts mortality in severe obstructive pulmonary disease

We evaluated the prevalence of chronotropic incompetence (CI), a marker of autonomic dysfunction, and its prognostic value in patients with chronic obstructive pulmonary disease (COPD). We performed a retrospective analysis of 449 patients with severe COPD who underwent a cardiopulmonary exercise test, after excluding patients with lung volume reduction surgery, left ventricular dysfunction and those not in sinus rhythm. CI was defined as percent predicted heart rate reserve (%HRR). Events were defined as death or lung transplant during a median follow-up of 68 months. Median age was 61 years; median percent predicted forced expiratory volume in one second (%FEV1) of 25% and median %HRR of 33%. The hazard ratio for an event in the lowest quartile of %HRR, taking the highest quartile as reference, was of 3.2 (95% confidence interval: 2.1-4.8; p < 0.001). In a multivariate regression model, %HRR was an independent predictor of events. In conclusion, Cl was an independent and powerful outcome predictor in patients with severe COPD. (C) 2013 Elsevier B.V. All rights reserved