Dubé, Kristy-Anne2017-03-222017-03-222017-03-03https://laurentian.scholaris.ca/handle/10219/2710Clostridium difficile infection (CDI) is the leading cause of nosocomial diarrhea worldwide. Prevention and treatment of CDI requires an intimate understanding of the immune response to the bacterium. Thus, this study investigated the plasma immune response of 79 patients at Health Sciences North in Sudbury, Ontario, Canada to identify immunodominant C. difficile proteins. Plasma samples were obtained from patients diagnosed with C. difficile infection, patients positive for C. difficile without symptoms, and patients who were negative for C. difficile, with and without symptoms. The plasma samples were tested for the presence of antibody reacting to C. difficile protein extracts using Western Blot analysis, Wes immunoblotting, and subsequent characterization by 2-D immunoblot analysis and mass spectrometry. Candidate immunodominant C. difficile proteins were found to be enolase, acetyl-coA acetyltransferase, and the 50s ribosomal protein, L7/L12. However, the presence and/or levels of antibodies that recognized these proteins in patient plasma were not statistically different between patient cohorts. Further analysis of the potential immunogenicity of these proteins could be useful to CDI treatment and preventionenClostridium difficile infection (CDI)immune responseimmunodominantasymptomatic carrierplasma IgGWes immunoblottingThesis