Search results for "Genome"
showing 10 items of 1913 documents
Two new Salmonella genomic islands 1 from Proteus mirabilis and description of blaCTX-M-15 on a variant (SGI1-K7)
2018
Objectives To characterize the structure of Salmonella genomic islands 1 (SGI1s) from two clinical Proteus mirabilis isolates: one producing an ESBL and the other a penicillinase. Methods WGS completed by PCR and Sanger sequencing was performed to determine sequences of SGI1s from Pm2CHAMA and Pm37THOMI strains. Results Two new variants of SGI1 named SGI1-Pm2CHAMA (53.6 kb) and SGI1-K7 (55.1 kb) were identified. The backbone of SGI1-Pm2CHAMA shared 99.9% identity with that of SGI1. Its MDR region (26.3 kb) harboured two class 1 integrons (an In2-type integron and an In4-type integron) containing in particular a qacH cassette (encoding a quaternary ammonium compound efflux pump). These two i…
Rhodoluna lacicola gen. nov., sp. nov., a planktonic freshwater bacterium with stream-lined genome
2014
A pure culture of an actinobacterium previously described as 'Candidatus Rhodoluna lacicola' strain MWH-Ta8 was established and deposited in two public culture collections. Strain MWH-Ta8(T) represents a free-living planktonic freshwater bacterium obtained from hypertrophic Meiliang Bay, Lake Taihu, PR China. The strain was characterized by phylogenetic and taxonomic investigations, as well as by determination of its complete genome sequence. Strain MWH-Ta8(T) is noticeable due to its unusually low values of cell size (0.05 µm(3)), genome size (1.43 Mbp), and DNA G+C content (51.5 mol%). Phylogenetic analyses based on 16S rRNA gene and RpoB sequences suggested that strain MWH-Ta8(T) is affi…
The frontier between cell and organelle: genome analysis of Candidatus Carsonella ruddii
2007
Background Bacterial symbioses are widespread among insects. The early establishment of such symbiotic associations has probably been one of the key factors for the evolutionary success of insects, since it may have allowed access to novel ecological niches and to new imbalanced food resources, such as plant sap or blood. Several genomes of bacterial endosymbionts of different insect species have been recently sequenced, and their biology has been extensively studied. Recently, the complete genome sequence of Candidatus Carsonella ruddii, considered the primary endosymbiont of the psyllid Pachpsylla venusta, has been published. This genome consists of a circular chromosome of 159,662 bp and…
Impact of analytic provenance in genome analysis
2014
Background Many computational methods are available for assembly and annotation of newly sequenced microbial genomes. However, when new genomes are reported in the literature, there is frequently very little critical analysis of choices made during the sequence assembly and gene annotation stages. These choices have a direct impact on the biologically relevant products of a genomic analysis - for instance identification of common and differentiating regions among genomes in a comparison, or identification of enriched gene functional categories in a specific strain. Here, we examine the outcomes of different assembly and analysis steps in typical workflows in a comparison among strains of Vi…
Rapid 96-well plates DNA extraction and sequencing procedures to identify genome-wide transposon insertion sites in a difficult to lyse bacterium: La…
2014
International audience; Random transposon mutagenesis followed by adequate screening methods is an unavoidable procedure to characterize genetics of bacterial adaptation to environmental changes. We have recently constructed a mutant library of Lactobacillus casei and we aimed to fully annotate it. However, we have observed that, for L. casei which is a difficult to lyse bacterium, methods used to identify the transposon insertion site in a few mutants (transposon rescue by restriction and recircularization or PCR-based methods) were not transposable for a larger number because they are too time-consuming and sometimes not reliable. Here, we describe a method for large-scale and reliable id…
The Evolutionary Fate of Nonfunctional DNA in the Bacterial Endosymbiont Buchnera aphidicola
2004
Reduction of the genome size in endosymbiotic bacteria is the main feature linked to the adaptation to a host-associated lifestyle. We have analyzed the fate of the nonfunctional DNA in Buchnera aphidicola, the primary endosymbiont of aphids. At least 164 gene losses took place during the recent evolution of three B. aphidicola strains, symbionts of the aphids Acyrthosiphon pisum (BAp), Schizaphis graminum (BSg), and Baizongia pistacia (BBp). A typical pattern starts with the inactivation of a gene, which produces a pseudogene, and is followed by the progressive loss of its DNA. Our results show that during the period from the separation of the Aphidinae and Pemphiginae lineages (86-164 MYA…
Evidence of Genomic Instability in Campylobacter jejuni Isolated from Poultry
1998
ABSTRACT Poultry isolates of Campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA to establish the clonal relationships between single-colony isolates. In the majority of batches studied, one or two genotype patterns predominated. However, in one batch (batch A), 21 single-colony isolates gave 14 different PFGE genotypes. The banding patterns obtained with Sma I were sufficiently different to distinguish between genotypes, although the patterns also produced many common bands. The question of whether these isolates represented different clones or had a common clonal ancestry was addressed by additi…
The respiratory microbiome in bronchial mucosa and secretions from severe IgE-mediated asthma patients
2017
Altres ajuts: This work was supported by Fundació Catalana de Neumología (FUCAP) and Centro de Investigación Biomédica en Red de Enfermedades Respiratorias(CIBERES). CIBERES is an initiative of the Instituto de Salud Carlos III. The bronchial microbiome in chronic lung diseases presents an abnormal pattern, but its microbial composition and regional differences in severe asthma have not been sufficiently addressed. The aim of the study was to describe the bacterial community in bronchial mucosa and secretions of patients with severe chronic asthma chronically treated with corticosteroids in addition to usual care according to Global Initiative for Asthma. Bacterial community composition was…
Analysis of microbiota in stable patients with chronic obstructive pulmonary disease
2014
To identify the bacterial diversity (microbiota) in expectorated sputum, a pyrosequencing method that investigates complex microbial communities of expectorated sputum was done in 19 stable chronic obstructive pulmonary disease patients (mean (SD) FEV1: 47 (18%) of predicted value). Using conventional culture, 3 phyla and 20 bacterial genera were identified, whereas the pyrosequencing approach detected 9 phyla and 43 genera (p < 0.001). In sputum the prevalent genera with pyrosequencing approach were Streptococcus, Actinomyces, Neisseria, Haemophilus, Rothia, Fusobacterium, Gemella, Granulicatella, Porphyromonas, Prevotella and Veillonella. Enterobacteriaceae, detected frequently in convent…
Fast and low-cost decentralized surveillance of transmission of tuberculosis based on strain-specific PCRs tailored from whole genome sequencing data…
2015
Molecular epidemiology has transformed our knowledge of how tuberculosis (TB) is transmitted. Whole genome sequencing (WGS) has reached unprecedented levels of accuracy. However, it has increased technical requirements and costs, and analysis of data delays results. Our objective was to find a way to reconcile speed and ease of implementation with the high resolution of WGS. The targeted regional allele-specific oligonucleotide PCR (TRAP) assay presented here is based on allele-specific PCR targeting strain-specific single nucleotide polymorphisms, identified from WGS, and makes it possible to track actively transmitted Mycobacterium tuberculosis strains. A TRAP assay was optimized to track…