Keywords
Biofilms, Enterococcus faecalis, Mutagenesis, Selenium
Abstract
Enterococcus faecalis is a well known nosocomial drug resistant pathogen that is responsible for urinary tract infections, bacteremia, wound infections and endocarditis through the formation of biofilms. It has been shown that 68 genes present within the core genome of E. faecalis are upregulated in biofilm formation. One of those 68 genes is a putative seleniumdependent molybdenum hydroxylase (SDMH). Adjacent to this gene are a series of open reading frames that have been postulated to play a role in the maturation of a labile selenium cofactor. The biosynthesis of this labile cofactor has yet to be studied at either the genetic or biochemical level. The addition of selenium to growth medium caused a significant increase in biofilm density and extracellular hydrogen peroxide by wild type E. faecalis. By site-directed mutagenesis gene products encoded in the SDMH operon were shown to be necessary for the selenium-dependent biofilm formation as well as extracellular hydrogen peroxide production. This biofilm and peroxide phenotype is inhibited both by tungsten or auranofin in wild type E. faecalis suggesting the SDMH is a necessary enzyme for selenium-dependent biofilm and peroxide formation. These results show that the gene products encoded within the SDMH operon are necessary for a selenium-dependent biofilm formation as well as extracellular hydrogen peroxide production. These mutants will provide the basis for defining the synthesis of the labile selenium cofactor and allow for an expanded understanding of the biological use of selenium.
Notes
If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu
Graduation Date
2010
Semester
Fall
Advisor
Self, William T.
Degree
Master of Science (M.S.)
College
College of Medicine
Department
Biomedical Sciences
Format
application/pdf
Identifier
CFE0003420
URL
http://purl.fcla.edu/fcla/etd/CFE0003420
Language
English
Release Date
December 2010
Length of Campus-only Access
None
Access Status
Masters Thesis (Open Access)
Subjects
Dissertations, Academic -- Medicine, Medicine -- Dissertations, Academic
STARS Citation
Mallard, Christopher J., "In-frame Mutagenesis Of Genes Encoding A Selenium-dependent Molybdenum Hydroxylase And Putative Accessory Proteins In Enterococcus Faecalis" (2010). Electronic Theses and Dissertations. 1640.
https://stars.library.ucf.edu/etd/1640