Characterization of Multispecies Biofilm Dispersion

Authors: Ankita Kundu, Francesca Mendejar, Aiden Park, Karin Sauer

Field of Study: Biological Sciences

Faculty Mentors: David G. Davies

Easel: 21

Timeslot: Afternoon

Abstract: Biofilm-associated infections are frequently polymicrobial and present significant challenges to infection control. Dispersion, the final stage of the biofilm life cycle, enables cells to detach and disseminate within the host, yet it remains poorly understood in Gram-positive and multispecies biofilms. This study investigates exogenous dispersion in biofilms formed by Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. Biofilms were grown as single-, double-, and triple-species communities and induced to disperse using either a five-fold increase in nutrient concentration or 310 nM cis-2-decenoic acid (cis-DA). Dispersion was evaluated by quantifying released cells, determining the timing of dispersion, and measuring extracellular matrix-degrading enzyme activity. Approximately 53–57% of biofilm cells dispersed following induction, while nutrient depletion did not trigger dispersion. In triple-species biofilms, P. aeruginosa dispersed first (20–25 min), whereas S. aureus and S. epidermidis showed delayed dispersion compared with their single-species biofilms. All species released enzymes capable of degrading carbohydrates, proteins, lipids, and DNA, suggesting coordinated matrix degradation during dispersion and highlighting potential targets for antibiofilm strategies.