Year of Graduation
2024
Level of Access
Restricted Access Thesis
Embargo Period
5-16-2024
Department or Program
Biochemistry
First Advisor
Danielle Dube
Abstract
The dangerous rise of antibiotic resistant bacteria in clinical infections demands the development of new antibiotics. Bacterial glycans are attractive antibiotic targets due to the highly divergent structures observed across bacterial species and their involvement in pathogenesis. Here, we turned to metabolic oligosaccharide engineering as a tool to probe the presence of bacterial monosaccharaides on the pathogenic bacteria Staphylococcus aureus, Helicobacter pylori, Plesiomonas shigelloides, and Vibrio vulnificus and commensal bacterium Bacteroides fragilis. In particular, we assessed the metabolic incorporation of peracetylated versus free N-azidoacetyl analogs of glucosamine, L-pneumosamine and L-rhamnosamine. Incorporation of the azido sugar probes into cellular glycans was assayed on live cells and in cell lysates. All pathogenic species preferentially incorporated the peracetylated probes, with strong incorporation onto cell surface glycans. Both S. aureus and B. fragilis were able to incorporate free sugars in addition to or in place of the peracetylated equivalent. Esterase activity assays in live cells and cell lysates revealed the presence of active esterase enzymes within these bacteria, supporting the use of peracetylated probes. These studies reveal insight into optimal design parameters of metabolic probes to study glycans in these bacteria.
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Available only to users on the Bowdoin campus.