Development and use of an efficient system for random mariner transposon mutagenesis to identify novel genetic determinants of biofilm formation in the core Enterococcus faecalis genome. Appl Environ Microbiol 2008 Jun;74(11):3377-86
Date
04/15/2008Pubmed ID
18408066Pubmed Central ID
PMC2423031DOI
10.1128/AEM.02665-07Scopus ID
2-s2.0-44949129965 (requires institutional sign-in at Scopus site) 81 CitationsAbstract
Enterococcus faecalis is a gram-positive commensal bacterium of the gastrointestinal tract and an important opportunistic pathogen. Despite the increasing clinical significance of the enterococci, most of the genetic analysis of these organisms has focused on mobile genetic elements, and existing tools for manipulation and analysis of the core E. faecalis chromosome are limited. We are interested in a comprehensive analysis of the genetic determinants for biofilm formation encoded within the core E. faecalis genome. To identify such determinants, we developed a substantially improved system for transposon mutagenesis in E. faecalis based on a mini-mariner transposable element. Mutagenesis of wild-type E. faecalis with this element yielded predominantly mutants carrying a single copy of the transposable element, and insertions were distributed around the entire chromosome in an apparently random fashion. We constructed a library of E. faecalis transposon insertion mutants and screened this library to identify mutants exhibiting a defect in biofilm formation. Biofilm-defective mutants were found to carry transposon insertions both in genes that were previously known to play a role in biofilm formation and in new genes lacking any known function; for several genes identified in the screen, complementation analysis confirmed a direct role in biofilm formation. These results provide significant new information about the genetics of enterococcal biofilm formation and demonstrate the general utility of our transposon system for functional genomic analysis of E. faecalis.
Author List
Kristich CJ, Nguyen VT, Le T, Barnes AM, Grindle S, Dunny GMAuthor
Christopher J. Kristich PhD Professor in the Microbiology and Immunology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
BiofilmsChromosomes, Bacterial
DNA Transposable Elements
Enterococcus faecalis
Genes, Bacterial
Genetic Complementation Test
Genome
Microscopy, Electron, Scanning
Mutagenesis, Insertional