Keywords

Clostridioides difficile, AgCNP, nanoparticle, spores, disinfection, abiotic surfaces

Abstract

The nosocomial pathogen Clostridioides difficile colonizes the gut leading to antibiotic-associated diarrhea, and severe inflammation. C. difficile spores—the main agent of transmission—survive for months on contaminated surfaces. Common disinfecting agents such as bleach and peroxides are used to prevent this; however, these chemicals are highly corrosive, toxic and pose serious health concerns. Seeking to address the challenges posed by conventional disinfectants, our research tested the feasibility of redox-active, silver-modified cerium oxide nanoparticles (AgCNP) formulations as a safer alternative. We tested the efficacy of AgCNP in rich culture media on C. difficile NAP1, a known hypervirulent strain associated with hospital endemics, and determined the minimum inhibitory concentration of these nanomaterials. In vitro growth kinetics of NAP1 and time-kill kinetics of AgCNP under different experimental conditions revealed a bactericidal effect of AgCNP against C. difficile. AgCNP-coated glass coupons mimicking actual environmental surfaces exhibited a 4-log reduction in germinating C. difficile spores, demonstrating sporicidal activity. This highlights the potential of AgCNP coatings on high-touch surfaces to mitigate CDI. However, we stumbled upon a curious phenomenon with sodium taurocholate, a bile salt that kickstarts spore germination. Viability studies and time-kill kinetics demonstrated that presence of sodium taurocholate attenuated bactericidal activity of AgCNP, resulting in a bacteriostatic mode of action. Cytotoxicity evaluations using MTT assay in MEF cells demonstrated that AgCNP displayed minimal toxicity at its bioactive concentration, outperforming equimolar hydrogen peroxide. This favorable biocompatibility profile highlights AgCNP promise for developing novel surface disinfection strategies against healthcare-associated infections like C. difficile.

Completion Date

2024

Semester

Summer

Committee Chair

Self, William

Degree

Master of Science (M.S.)

College

College of Medicine

Department

Burnett School of Biomedical Sciences

Degree Program

Biotechnology

Format

application/pdf

Identifier

DP0028885

URL

https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1472&context=etd2023

Language

English

Rights

In copyright

Release Date

2-15-2025

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Campus Location

Orlando (Main) Campus

Accessibility Status

Meets minimum standards for ETDs/HUTs

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