Abstract
While previous studies have shown that presence of bacteria in systemic circulation can cause infective endocarditis, there is no information on the specific amount of bacteria necessary to cause this condition. The purpose of this study was to establish the minimum level of circulating bacteria that will cause colonization of damaged heart valves in rats. Fifty-two Sprague-Dawley rats were anesthetized and their heart valves were damaged using an established protocol. A clinical isolate of Enterococcus faecalis was transformed with a plasmid bearing the luxF and Chloramphenicol cassettes to label the bacteria with the light-emitting protein. After four weeks, the rats were re-anesthetized and intravenously injected with various concentrations of the labeled E. faecalis ranging from 1 x 102 to 1 x 108 cells in a 100 μl volume. The animals were sacrificed one week after infection and the hearts were excised and incubated overnight in brain heart infusion containing chloramphenicol. The presence or absence of luminescent bacteria was examined under a low light imager and recorded. All animals injected with 1 x 108 E. faecalis cells consistently demonstrated colonization of their heart valves. Variable incidence of colonization was also observed in animals injected with 1 x 103 to 1 x 107 cells. None of the rats injected with 5 x 102 or 1 x 102 bacterial cells demonstrated colonization of their heart valves. This study has established for the first time the lowest level of bacteria, which can cause colonization of damaged heart valves in rats.
School
Graduate School
First Advisor
Mahmoud Torabinejad
Second Advisor
Alan Escher
Third Advisor
Shahrokh Shabahang
Degree Name
Master of Science (MS)
Degree Level
M.S.
Year Degree Awarded
2004
Date (Title Page)
9-2004
Language
English
Library of Congress/MESH Subject Headings
Enterococcus Faecalis; Heart Valve; Heart Valve Diseases; Endocarditis, Bacterial
Type
Thesis
Page Count
viii; 33
Digital Format
Digital Publisher
Loma Linda University Libraries
Copyright
Author
Usage Rights
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Recommended Citation
Stromberg, Louis Zane, "Levels of Intravenous Enterococcus faecalis That Cause Heart Colonization" (2004). Loma Linda University Electronic Theses, Dissertations & Projects. 2481.
https://scholarsrepository.llu.edu/etd/2481
Collection
Loma Linda University Electronic Theses and Dissertations
Collection Website
http://scholarsrepository.llu.edu/etd/
Repository
Loma Linda University. Del E. Webb Memorial Library. University Archives
Included in
Animal Experimentation and Research Commons, Bacteria Commons, Cardiovascular System Commons, Endodontics and Endodontology Commons