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

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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

Restricted to the UCF community until December 2010; it will then be open access.

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