Search

Phylogenetic diversities of the endolithic bacterial communities in dolomite and limestone rocks from a karst canyon (Nanjiang Canyon), China, were analyzed based on the 16S rRNA gene analysis. In the dolomite endolithic bacterial communities, members of Cyanobacteria were the most abundant followed in abundance by members of Alphaproteobacteria, Acidobacteria, and Actinobacteria. Members of Betaproteobacteria, Deltaproteobacteria, Bacteriodetes, Verrucomicrobia, and Chloroflexi were also present. Large percentages of bacterial clones in the limestone were related to the Actinobacteria, Alphaproteobacteria, and Cyanobacteria. In addition, members of Deltaproteobacteria, Bacteriodetes, Chloroflexi, Acidobacteria, Firmicutes, Planctomycetes, and Candidate division TM7 were identified. Slight differences in endolithic bacterial abundance and community structure existed between the dolomite and limestone rocks. These rock microorganisms are inferred to have played an important role in the formation of Karst soil from carbonate rocks during a long geological history. [ABSTRACT FROM AUTHOR]

Abstract: A polyphasic taxonomic study was performed on seven Bacillus-like bacteria isolated from three hypersaline and alkaline lakes located in China, Kenya and Tanzania. All strains were moderately halophilic and alkaliphilic, Gram positive, motile rods. The DNA G+C content from the seven isolates ranged from 42.2 to 43.4mol% and their major fatty acid was anteiso-C15:0. Strain CG1T, selected as representative strain of the isolates, possesses meso-diaminopimelic acid in the cell wall peptidoglycan, MK-7 as the predominant menaquinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. Comparative 16S rRNA gene sequence analysis indicated that the isolates belonged to the genus Bacillus. The seven isolates shared 97.7–99.9% 16S rRNA gene sequence similarity, and formed a branch that was distinct from the type strains of the recognized species of the genus Bacillus. They were most closely related to Bacillus agaradhaerens DSM 8721T (92.6–93.8% 16S rRNA sequence similarity). DNA–DNA hybridization values between the seven isolates were 85–100%. According to the polyphasic characterization, the strains represent a novel species, for which the name Bacillus locisalis sp. nov. is proposed. The type strain is CG1T (CCM 7370T =CECT 7152T =CGMCC 1.6286T =DSM 18085T). [Copyright &y& Elsevier]

Introduction: Current strategies for the prevention of acute exacerbations in chronic obstructive pulmonary disease (COPD) are primarily based on clinical measurements but fail to target the pathophysiological mechanisms, namely endotypes, of the disease. Studies identifying endotypes underlying exacerbation susceptibility and discovering specific biomarkers may lead to the development of targeted therapeutics but are lacking. This study aims to assess a broad spectrum of biomarkers at multiple biological levels (genetics, airway inflammation and respiratory microbiome) for their ability in predicting acute exacerbations of COPD, thus enables high-resolution disease endotyping and may lead to precision treatment of the disease., Methods and Analysis: In this prospective cohort study, participants with stable COPD (n=600) will be recruited and assessed for demographics, symptom scores, spirometry, medication use and comorbidities at baseline. Blood will be obtained for genotyping variants in a panel of nine genes. Induced sputum will be collected for the profile of microbiota using 16S rRNA gene sequencing, quantification of bacterial load, inflammatory mediators assay and sputum cytometry. Participants will be followed up for their exacerbations till 12 months and reassessed for the clinical measurements as baseline. The primary outcomes are total number of exacerbations, severe exacerbations, moderate exacerbations and time to first exacerbation. The secondary outcomes are changes in lung function and symptom scores. The effect of biomarkers representing genetic variants, airway inflammation and respiratory microbiome on predicting the frequent exacerbator phenotype and exacerbation frequency will be analysed with multivariable modelling, and time to first exacerbation with a Cox regression model., Ethics and Dissemination: The study has been approved by the Clinical Trial and Biomedical Ethics Committee of West China Hospital of Sichuan University (No. 2018-298). The results of the study will be published on peer-reviewed journals., Trial Registration Number: ChiCTR1800019063., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)