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Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

2008

Theses and Dissertations

Streptococcus sanguinis

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Full-Text Articles in Medicine and Health Sciences

Identification Of Virulence Determinants For Streptococcus Sanguinis Infective Endocarditis, Lauren Turner Aug 2008

Identification Of Virulence Determinants For Streptococcus Sanguinis Infective Endocarditis, Lauren Turner

Theses and Dissertations

Streptococcus sanguinis is the second most common causative agent of bacterial infective endocarditis (IE). Risk of S. sanguinis IE is dependent on pre-disposing damage to the heart valve endothelium, which results in deposition of clotting factors for formation of a sterile thrombus (referred to as vegetation). Despite medical advances, high mortality and morbidity rates persist. Molecular characterization of S. sanguinis virulence determinants may enable development of prevention methods. In a previous screen for S. sanguinis virulence determinants by signature-tagged mutagenesis (STM) an attenuated mutant was identified with a transposon insertion in the nrdD gene, encoding an anaerobic ribonucleotide reductase. Evaluation …


Physiological And Molecular Characterization Of Genetic Competence In Streptococcus Sanguinis, Alejandro Rodriguez Jul 2008

Physiological And Molecular Characterization Of Genetic Competence In Streptococcus Sanguinis, Alejandro Rodriguez

Theses and Dissertations

The ability of bacteria to assimilate free DNA from the environment is known as competence. Though many studies have focused on competence regulation in Streptococcus pneumoniae and Streptococcus gordonii, Streptococcus sanguinis has yet to be examined. Physiological characterization of competence in S. sanguinis strain SK36 and its comC mutant, JFP41, led to the genome-wide transcriptional analysis of cells induced to competence via addition of competence-stimulating peptide (CSP). A total of 128 genes were induced at least 2-fold, 74 of which were classified as either “early” or “late” based on their induction patterns. Expression patterns were verified using qRT-PCR. This study …