Clostridioides difficile is a Gram positive, spore-producing, anaerobic bacterium. It is considered a nosocomial pathogen due to high incidence rates of C. difficile infections (CDI) in hospitals. However, research reveals an increase in community-associated cases. CDI is most common in the elderly, immunocompromised, or those taking a course of antibiotics. These individuals are more vulnerable to experiencing gut dysbiosis, allowing C. difficile to colonize the colon. CDI are an urgent threat due to their ability to sporulate. Spores are hardy and not eradicated by common disinfectants. They persist on surfaces the patient may have contact with during CDI. Current decontamination methods include the utilization of bleach-based disinfectants followed by ultraviolet (UV) light and adherence to a strict quality control protocol. However, spores may remain in the environment even after this process, thus allowing the pathogen to spread through surface contact. Another problem is the cost incurred by the hospital over time in terms of inpatient and equipment turnover related costs. These reasons make it imperative a better means of disinfection is developed. Silver is a known antimicrobial agent and utilized in clinical settings for burn treatment. Cerium oxide nanoparticles (CNP) possess antioxidant properties and can be used for drug delivery. Preliminary studies show silver-modified CNP (AgCNP) possess antiviral activity against COVID-19 and rhinovirus. To study the antimicrobial effects of the AgCNP against vegetative cells, a three-day time-kill assay was performed. Two strains of C. difficile, R20291 and NAP1, were cultured in BHIS (brain heart infusion, supplemented) and grown overnight. Glass coupons coated with AgCNP1 or AgCNP3, CNP1 or CNP3, or left uncoated were used in this study. They were incubated with cell culture at a variety of time points. The results indicate AgCNP3 may possess bactericidal activity. Further research should be conducted to determine the extent of this activity.
Bachelor of Science (B.S.)
College of Medicine
Burnett School of Biomedical Sciences
Length of Campus-only Access
Gupta, Saloni, "The Effects of Silver-Modified Nanoceria on Clostridioides difficile Vegetative Cells in an in vitro Environment" (2023). Honors Undergraduate Theses. 1482.