Investigation of Antimicrobial Activity of Cartaderia selloana, Pampas Grass

Foodborne infections affect millions of people in both developed and developing countries. Many of these infections are due to contaminated food or water. Therefore there is a constant need for new antimicrobial agents to prevent survival and growth of bacteria in food. The use of natural compounds from plants can provide an alternative approach against foodborne pathogens. Cortaderia selloana, pampas grass, is an invasive species outside of its native South American habitat. Our hypothesis is this plant has antimicrobial activity against pathogens which contribute to its success. The aim of our work is to explore the antimicrobial properties of C. selloana. In this experiment, extracts of roots, flowers, leaves, and stems were made in ethyl acetate and water. The extracts were then screened against Staphylococcus aureus (gram-positive), Escherichia coli (gram-negative) bacteria, and Saccharomyces cerevisiae (fungus) using agar diffusion assays. The ethyl-acetate leaf extract (333 mg/ml) inhibited all of the test microbes with zones of inhibition ranging from 13.1 to 14.0 mm. The minimum bactericidal concentration of the leaf extract against Sa. cerevisiae and against E. coli is 41.67 mg/mL. The chemical nature of the antimicrobial compound(s) is being determined. The effectiveness of the leaf extract preventing E. coli survival and growth in fresh produce is being determined. The results so far indicate that C. selloana has the potential to be a natural antimicrobial to prevent foodborne gram-negative bacterial infection.