Basil (Ocimum Spp.) Leaf Extracts as Inhibitors of Methicillin-resistant Staphylococcus aureus Growth and Quorum Sensing
Open Access
- Author:
- Boltz, Danika
- Area of Honors:
- Veterinary and Biomedical Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Joshua J Kellogg, Thesis Supervisor
Robert John Vansaun, Thesis Honors Advisor - Keywords:
- basil
MRSA
AIP
MIC
ocimum - Abstract:
- Methicillin-resistant Staphyococcus aureus (MRSA) is a pathogen of concern worldwide. Increased drug resistance within the various strains has made it difficult to treat MRSA infections, creating a need for new products capable of inhibiting MRSA growth and pathogenicity. Ocimum species have a long history of use in traditional medicine, including being used as a treatment for bacterial infections. The goal of this thesis project is to evaluate the ability of O. basilicum, O. tenuiflorum, and O. gratissimum methanolic extracts to inhibit both MRSA growth and auto-inducing peptide (AIP) production, and to determine whether antimicrobial activity is impacted by the unique metabolite profiles of each species. Growth inhibition ability was evaluated via a visually assessed MIC assay, while AIP production inhibition was quantified via an LC-MS AIP assay. Results of the MIC assay did not indicate a strong ability for methanolic basil extracts to inhibit MRSA, and there was no clear difference between the sample species and the ability to inhibit MRSA growth. The results of the AIP assay indicate that methanolic basil extracts have the potential to inhibit AIP production and there was significant species variation of the activity. A one-way ANOVA test revealed that O. basilicum species had significantly lower AIP inhibition compared to O. gratissimum and O. tenuiflorum. Analysis of the metabolites within each basil sample to determine which metabolites are bioactive may help to identify the mechanism via which methanolic basil extracts inhibit the production of AIP by MRSA.