Inhibition Of Microbial Biofilms

The purpose of this research is to identify the antibacterial effect of different substances, including mealworm, earthworm, lichen and cranberry extracts, have on Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli and Pseudomonas fluorescens, and their effectiveness in inhibiting the formation of biofilms, as well as removing formed biofilms of bacteria. Biofilms are microbially derived sessile communities characterized by cells that are irreversibly attached to a substratum and embedded in a matrix. They can adhere to medical devices, causing contamination and infection. The first phase of the project involved using a well diffusion assay in the antibacterial test. Only lichen extract displayed antibacterial effect against S. epidermidis and P. fluorescens. The next phase involved a microtitre plate assay to determine the effectiveness of extracts in inhibiting the formation of biofilms and removing formed biofilms. Mealworm and earthworm extracts were effective in both inhibiting and removing biofilms of S. epidermidis and E. coli. The Kruskal- Wallis test showed significant difference in the absorbance among the samples with earthworm extract, mealworm extract, and control without extract.