Project description:Within this work we identified and characterized gene Bmul_2557 (ldhR) of B. multivorans ATCC 17616, a bacterial species associated with chronic respiratory infections in cystic fibrosis patients. LdhR belongs to the LysR-type family of transcriptional regulators and its deletion from the B. multivorans genome affected considerably the formation of planktonic cellular aggregates and surface-attached biofilms.
Project description:An efficient and quantitative method to analyze the transposition of various insertion sequence (IS) elements in Burkholderia multivorans ATCC 17616 was devised. pGEN500, a plasmid carrying a Bacillus subtilis-derived sacB gene, was introduced into ATCC 17616 cells, and 25% of their sucrose-resistant derivatives were found to carry various IS elements on pGEN500. A PCR-based experimental protocol, in which a mixture of several specific primer pairs was used, revealed that pGEN500 captured, in addition to five previously reported IS elements (IS401, IS402, IS406, IS407, and IS408), three novel IS elements, ISBmu1, ISBmu2, and ISBmu3. The global transposition frequency of these IS elements was enhanced more than sevenfold under a high-temperature condition (42 degrees C) but not under oxidative stress or starvation conditions. To our knowledge, this is the first report demonstrating the elevated transposition activities of several IS elements at a high temperature. The efficient experimental protocol developed in this study will be useful in quantitatively and simultaneously investigating various IS elements, as well as in capturing novel functional mobile elements from a wide variety of bacteria.
Project description:The gene expression of the opportunictic cystic fibrosis lung pathogen Burkholderia multivorans ATCC 17616 was investigated under different growth conditions relevant for growth in the cystic fibrosis lung.
Project description:The gene expression of the opportunictic cystic fibrosis lung pathogen Burkholderia multivorans ATCC 17616 was investigated under different growth conditions relevant for growth in the cystic fibrosis lung.
Project description:The gene expression of the opportunictic cystic fibrosis lung pathogen Burkholderia multivorans ATCC 17616 was investigated under different growth conditions relevant for growth in the cystic fibrosis lung.
Project description:The Burkholderia multivorans strain ATCC 17616 carries three circular chromosomes with sizes of 3.4, 2.5, and 0.9 Mb. To determine the distribution and organization of the amino acid biosynthetic genes on the genome of this beta-proteobacterium, various auxotrophic mutations were isolated using a Tn5 derivative that was convenient not only for the determination of its insertion site on the genome map but also for the structural analysis of the flanking regions. Analysis by pulsed-field gel electrophoresis revealed that 20 out of 23 insertion mutations were distributed on the 3.4-Mb chromosome. More detailed analysis of the his, trp, arg, and lys mutations and their flanking regions revealed the following properties of these auxotrophic genes: (i) all nine his genes were clustered on the 3.4-Mb chromosome; (ii) seven trp genes were organized within two distinct regions, i.e., a trpEGDC cluster on the 3.4-Mb chromosome and a trpFBA cluster on the 2.5-Mb chromosome; (iii) the leu gene cluster, leuCDB, was also located close to the trpFBA cluster; and (iv) lysA and argG genes were located on the 2.5-Mb chromosome, in contrast to the argH gene, which was located on the 3.4-Mb chromosome. Southern hybridization analysis, allelic exchange mutagenesis of ATCC 17616, and complementation tests demonstrated that all of the genes examined were functional and existed as a single copy within the genome. The present findings also indicated that the 2.5-Mb chromosome carried various auxotrophic genes with no structural or functional counterparts on the remaining two chromosomes.
Project description:Burkholderia cepacia complex (Bcc) comprises opportunistic bacteria infecting hosts such as cystic fibrosis (CF) patients. Bcc long-term infection of CF patient airways has been associated with emergence of phenotypic variation. Here we studied two Burkholderia multivorans clonal isolates (D2095 and D2214) displaying different morphotypes from a chronically infected CF patient in order to evaluate traits development during lung infection.