Abstract
Pharyngitis (strep throat) is a bacterial throat infection caused by Streptococcus pyogenes. Antibiotics are the most frequent prescription against pharyngitis. However, overprescription of antibiotics can lead to antibiotic-resistance, which can make treatment of bacterial infections more difficult over time. This experiment explores plant medicine as a potential alternative to antibiotics by analyzing the antibacterial effect of a plant-derived chemical called spilanthol. The goals of this experiment were to analyze the inhibitory effect and Minimal Inhibitory Concentration (MIC) of spilanthol extracted from the plant Acmella oleracea on Streptococcus pyogenes. Serial two-fold dilutions in a 96-well plate were carried out for spilanthol dilutions (in 10% DMSO) against 10% DMSO controls. Differences in optical density at 660 nm (OD660) between the dilution assay and DMSO control were analyzed. Any negative differences in OD660meant spilanthol exhibited inhibition beyond DMSO, indicating that spilanthol may have an
inhibitory effect on Streptococcus pyogenes. After analyzing trials individually as well as trends between the trials, it was noted that the inhibition increased as the spilanthol concentration increased. Regarding the MIC, the incline in OD660 was gradual, making it difficult to accurately interpret the MIC of spilanthol. High variability between samples coupled with low sample size means further trials are necessary to determine the MIC of spilanthol.