Genome-scale analysis of the genes that contribute to Burkholderia pseudomallei biofilm formation identifies a crucial exopolysaccharide biosynthesis gene cluster
| Autor: | Ivo Steinmetz, Grace I. Borlee, Mihnea R. Mangalea, Mary N. Burtnick, Paul J. Brett, David P. AuCoin, Brooke A. Plumley, Dean C. Crick, M. Nurul Islam, Kevin H. Martin, John T. Belisle, Nawarat Somprasong, Bradley R. Borlee, Herbert P. Schweizer |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Exopolysaccharides Burkholderia pseudomallei Burkholderia cenocepacia Mutant Glycobiology Gene Expression Biochemistry Database and Informatics Methods Mobile Genetic Elements Gene cluster Comparative Genomic Hybridization lcsh:Public aspects of medicine Polysaccharides Bacterial Genomics 3. Good health Infectious Diseases Multigene Family Sequence Analysis Research Article Transposable element lcsh:Arctic medicine. Tropical medicine Multidrug tolerance Bioinformatics lcsh:RC955-962 030106 microbiology Biology Biosynthesis Research and Analysis Methods Microbiology Bacterial genetics 03 medical and health sciences Genetic Elements Polysaccharides Genetics Gene Regulation Gene Transposable Elements Public Health Environmental and Occupational Health Biofilm Biology and Life Sciences lcsh:RA1-1270 Gene Expression Regulation Bacterial biochemical phenomena metabolism and nutrition bacterial infections and mycoses biology.organism_classification Genetic Loci Biofilms Mutation bacteria Sequence Alignment Genome Bacterial |
| Zdroj: | PLoS Neglected Tropical Diseases, Vol 11, Iss 6, p e0005689 (2017) PLoS Neglected Tropical Diseases |
| ISSN: | 1935-2735 |
| Popis: | Burkholderia pseudomallei, the causative agent of melioidosis, is an important public health threat due to limited therapeutic options for treatment. Efforts to improve therapeutics for B. pseudomallei infections are dependent on the need to understand the role of B. pseudomallei biofilm formation and its contribution to antibiotic tolerance and persistence as these are bacterial traits that prevent effective therapy. In order to reveal the genes that regulate and/or contribute to B. pseudomallei 1026b biofilm formation, we screened a sequence defined two-allele transposon library and identified 118 transposon insertion mutants that were deficient in biofilm formation. These mutants include transposon insertions in genes predicted to encode flagella, fimbriae, transcriptional regulators, polysaccharides, and hypothetical proteins. Polysaccharides are key constituents of biofilms and B. pseudomallei has the capacity to produce a diversity of polysaccharides, thus there is a critical need to link these biosynthetic genes with the polysaccharides they produce to better understand their biological role during infection. An allelic exchange deletion mutant of the entire B. pseudomallei biofilm-associated exopolysaccharide biosynthetic cluster was decreased in biofilm formation and produced a smooth colony morphology suggestive of the loss of exopolysaccharide production. Conversely, deletion of the previously defined capsule I polysaccharide biosynthesis gene cluster increased biofilm formation. Bioinformatics analyses combined with immunoblot analysis and glycosyl composition studies of the partially purified exopolysaccharide indicate that the biofilm-associated exopolysaccharide is neither cepacian nor the previously described acidic exopolysaccharide. The biofilm-associated exopolysaccharide described here is also specific to the B. pseudomallei complex of bacteria. Since this novel exopolysaccharide biosynthesis cluster is retained in B. mallei, it is predicted to have a role in colonization and infection of the host. These findings will facilitate further advances in understanding the pathogenesis of B. pseudomallei and improve diagnostics and therapeutic treatment strategies. Author summary B. pseudomallei, the etiological agent of melioidosis, is an emerging pathogen with limited therapeutic options and no available vaccines. A better understanding of the role of biofilm formation during pathogenesis will aid in melioidosis diagnosis and the development of new therapeutics and vaccines. Melioidosis has both acute and chronic disease manifestations in addition to a highly variable period of latency, which contributes to complications in diagnosis and treatment of the disease. Relapsing melioidosis is correlated with biofilm formation and the role of biofilm growth during chronic human infections has been widely accepted. We utilized a two-allele sequence defined transposon mutant library of B. pseudomallei 1026b to identify genes involved in biofilm formation. This study identified factors that contribute to biofilm formation and included a previously undescribed exopolysaccharide and the genes underlying its biosynthesis. Since antibiotic tolerance in B. pseudomallei has been associated with biofilm formation, the genes identified in this study that contribute to biofilm production are potential targets for therapeutic development. Additionally, the products of these biofilm genes could be used for the development of diagnostics and vaccines. |
| Databáze: | OpenAIRE |
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