Investigation of the Role of Gene SA1798 in S. aureus
Open Access
- Author:
- Cole, Kaitlin
- Area of Honors:
- Biochemistry and Molecular Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Timothy Charles Meredith, Thesis Supervisor
Ming Tien, Thesis Honors Advisor - Keywords:
- Staphylococcus aureus
tunicamycin
antibiotic resistance
SA1798
SA618 - Abstract:
- Staphylococcus aureus remains a prevalent pathogen responsible for a wide range of infections. S. aureus is a gram-positive bacterium that is particularly problematic due to the emergence of antibiotic resistant forms. The cell wall is a major target for antibiotics because of structural differences between the cell walls of bacteria compared with eukaryotic cells. Previous research has found that the gene SA618 is important in resistance of S. aureus to the antibiotic tunicamycin. However, overexpression of the gene SA1798 has been shown to suppress this phenotype of increased susceptibility in ΔSA618 strains. In this study, the role of SA1798 was investigated through analysis of the phenotype of cells with a single nucleotide polymorphism in the promoter region of the gene. Further, the role of SA1798 in the structure of the peptidoglycan and wall teichoic acids in S. aureus was investigated. Elevated expression of SA1798 was found to decrease susceptibility of ΔSA618 strains to tunicamycin and the point mutation investigated in the promoter region was confirmed to lead to higher levels of SA1798 expression. There was no indication that SA1798 played a role in modifying the peptidoglycan structure or altered the structure of wall teichoic acid in S. aureus. Finally, the role of SA618 in virulence factor expression was investigated. Expression levels of the virulence factor spdC did not alter susceptibility of ΔSA618 or ΔSA1798 strains to tunicamycin. Differential gene expression depending on levels of SA618 expression were observed for the virulence factors sceD, agr, and asp23 in northern blots.