Honors Theses

Date of Award

5-2026

Document Type

Undergraduate Thesis

Degree Name

BS

Department

Biomedical Sciences

Faculty Mentor

Terrence J. Ravine, Ph.D.

Advisor(s)

Catherine W. Brock, Ph.D. and Padmamalini Thulasiraman, Ph.D.

Abstract

This project will focus on determining if differences in bacterial cell wall composition influences adhesiveness to thermoplastic materials used to construct patient orthotic splints. Bacteria with decreased adhesion are unable to remain bonded to orthotic splints, increasing its ability to transfer to a patient’s wound, leading to an infection. Antibiotic resistant bacteria used in this investigation included gram-positive cocci vancomycin-resistant (VRE) Enterococcus faecalis, methicillin-resistant Staphylococcus aureus (MRSA), and gram-negative rods extended-spectrum beta-lactamase (ESBL) Escherichia coli and Pseudomonas aeruginosa. Each test bacterium is a major pathogen causing healthcare-associated infections (HAIs). Saline, artificial perspiration, and ascites fluids were used to determine the effects of fluid composition on adhesion after either 1 hour or 24 hours contact with different thermoplastics. Each investigation demonstrated that gram-positives were more easily removed across all three thermoplastics when compared to gram-negatives, regardless of fluid type. Additionally, that reduced removal of all tested bacteria was seen at 24 hours. Specifically, VRE demonstrated greater removal at both 1- and 24-hour intervals from all thermoplastics indicating the least adhesion. In contrast P. aeruginosa demonstrated the least removal at both 1- and 24-hour intervals from all thermoplastics indicating greater adhesion. My results contribute to an enhanced understanding of bacterial-thermoplastic interactions as it related to infection potential. Additionally, they support prior investigations where gram-positive bacteria were the predominant bacteria recovered from sampling both in-use thermoplastic patient radiation therapy masks and orthotic splints. Further investigation such as scanning electron microscopy is warranted to look for differences in biofilm development between gram-positive and gram-negative bacteria.

Download

Share

COinS