Controlled-release Antimicrobials for Preventing Biofilm Formation in Food and Medical Applications

OF THE THESIS CONTROLLED-RELEASE ANTIMICROBIALS FOR PREVENTING BIOFILM FORMATION IN FOOD AND MEDICAL APPLICATIONS By LINDA E. ROSENBERG Thesis Director: Dr. Michael Chikindas Bacterial biofilms generally are more resistant to stresses as compared to free planktonic cells. Therefore, the discovery of antimicrobial stress factors that have strong inhibitory effects on bacterial biofilm formation would have great impact on the food, personal care, and medical industries. Biofilm formation can be prevented through controlled release of nature-derived antimicrobials formulated into polymer systems, especially those featuring multiple stresses as hurdles for the bacteria to overcome to prevent the development of resistance. Salicylate-based poly(anhydride-esters) have previously been shown to inhibit biofilm formation. Our research evaluated the effect of salicylate-based poly(anhydrideesters) on biofilm forming Salmonella enterica serovar Typhimurium. The results indicate that the salicylic acid-based polymers do interfere with biofilm formation through a combination of pH effects and a thus-far-unknown mechanism. Systems combining pH stress with the controlled release of natural antimicrobials have great potential to prevent biofilm development in many environments to prevent adverse outcomes, especially implant contamination and foodborne illness.