The Effectiveness of Uzarigenin as an Antiseptic against Staphylococcus aureus

by Gabrielle Moore

Faculty Mentor: Professor Lynn Lewis

To determine the effectiveness of uzarigenin on S. aureus, the agar disk diffusion method was first completed to study the cytotoxicity effect of uzarigenin directly on the bacteria. A cytotoxicity assay was then completed to test the cytotoxicity of the uzarigenin on the human epithelial fibroblasts themselves. After, a TCID50 assay was used to test for a preventative dose of uzarigenin against S. aureus to determine at what dilutions the uzarigenin can protect the cells from infection at least 50% of the time. It was found that there was an average 8.5 mm zone of inhibition compared to a standard 26.4 mm zone of inhibition by tetracycline. Since there may be different diffusion rates, S. aureus may be resistant to uzarigenin. It was also found that the uzarigenin caused cytopathic effects (CPE, changes in the host cell morphology due to infection) on the human epithelial fibroblasts up until a dilution of 10^-6. Additionally, the 10^-6 and 10^-9 dilutions of uzarigenin were effective in combatting an infection from S. aureus, leaving little to no traces of cytopathic effect. However, dilutions further than 10^-9 seemed to be too diluted to combat an infection, which resulted in CPE in all or most of the wells. Furthermore, the preventative dose for uzarigenin against S. aureus was found to be 10^11.2. In conclusion, uzarigenin may be able to be used as an antiseptic.