Researcher ORCID Identifier

Graduation Year


Date of Submission


Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts



Reader 1

Pete Chandrangsu

Reader 2

Anna Wenzel


The ongoing battle against antibiotic resistance implores us to look deeper into traditional medicines. Copper is documented as an ancient Egyptian treatment for a variety of ailments in the Smith Papyrus and the Ebers Papyrus. Staphylococcus epidermidis symbiotically lives on human skin and mucus but is an opportunistic pathogen once it invades the human body. These invasions primarily occur via medical and prosthetic devices, making it one of the leading causes of nosocomial infections. To understand how S.epidermidis evolves resistance to the antimicrobial effects of copper, multiple generations of S.epidermidis were grown in increasing concentrations of Cu. The initial MIC was nearly doubled from 3-4mM Cu to 5-6mM Cu. Eight colonies of the evolved strain underwent genome sequencing to determine the potential mutations that caused their copper resistance. All colonies were found to have a mutation in a putative Nramp family divalent metal transporter gene. We created in-frame deletion of the NRAMP gene and found that the clean deletion phenocopies the evolved Cu-resistant strain. Our findings will contribute to the discovery of novel antibiotic treatments to combat Staphylococcal infections.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.