Enterococci have emerged over the past few decades as the second or third most common cause of nosocomial infectious disease including urinary tract infections, soft tissue infections, bacteremia, meningitis and endocarditis. Enterococci are well equipped to thrive in an over-medicated environment due to both their intrinsic resistance to antibiotics their talent in swapping genetic information, which allows them to gain and share resistance determinants. The widespread swapping of genetic information is illustrated in the first publicly available genome; strain V583 is more than one-quarter mobile DNA, more than any other sequenced bacterial genome to date. In addition to contributing to antibiotic resistance, this proclivity to share DNA has likely led to much variation between different strains of Enterococcus faecalis.

This project will perform a detailed comparison of closely related genomes of E. faecalis strains: OG1RF, the most commonly studied research strain; HH22, a close relative of the only E. faecalis strain to be sequenced (V583) but which is 15 times more virulent than V583 in a mouse model; and TX0104, another endocarditis strain. The information generated will be analyzed with particular regard to virulence factors, and will serve as the basis for future studies comparing other E. faecalis genomes as well as hypotheses generated from this work as to critical genes for virulence.