Staphylococcus aureus biofilm formation and clogging dynamics within microfluidic environments

Abstract

Biofilm formation poses a significant problem in industrial and medical transport systems. Research about biofilm dynamics in fluid flow environments has revealed that biofilms behave as deformable materials that develop complex flow dependent structures. Specifically, the development of biofilm streamers trailing from rippled and curved surfaces is associated with the disruption of bulk fluid motion and rapid clogging. Current difficulties in preventing bacterial colonization and infection of implanted medical devices originate from our nascent understanding of the complex biological and physical factors that influence biofilm behavior. Research on species such as Staphylococcus aureus, Pseudomonas aeruginosa and others demonstrate that biofilm formation is regulated by quorum sensing; a process in which bacteria control gene expression in response to cell density. The Staphylococci agr (accessory gene regulator) biochemical signaling network plays a crucial role in the initiation of biofilm degradation and virulence expression (Novick et al. 2008). Augmenting our existing understanding of biofilm formation and behavior, we investigated the effects of key biological and physical conditions on bioclogging processes in microscale flow environments. Our findings suggest that bioclogging occurs more rapidly within microfluidic environments as fluid flow rates and bacterial cell densities increase. Moreover, we observed that S. aureus biofilm clogging dynamics exhibit no dependence on agr signaling. Overall, our results suggest that geometric features and physical conditions have significant effects on the timescales for S. aureus biofilm formation within flow environments.