A Multifactor Analysis of Polymicrobial Wound Pathogenic Biofilms Using Conventional Assays, Nanoscale Imaging, and a Microfluidic Platform

This thesis investigates Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) pathogenic wound biofilms through a multifactor analysis. P. aeruginosa and MRSA are commonly found in chronic wound biofilms. Chronic wounds are of major concern to healthcare systems and medical professionals as they are costly to treat and often become infected. Co-culture biofilm studies are relatively novel. Quantitative results (P < 0.05) show that P. aeruginosa and MRSA act competitively, with P. aeruginosa being the dominant species. Co-culture biofilms were shown to produce less biofilm biomass than their mono-culture counterparts. Examination of microbial adhesion kinetics to various material-surfaces using Kelvin probe force microscopy revealed that both microorganisms preferred adhesion to positively charged surfaces. Measurements of cell surface potentials revealed significant changes upon adhesion to different material-surfaces and from co-culturing. Chemotaxis experiments using a nanoporous microfluidic platform showed that wound relevant cytokine VEGF acts as a chemoattractant and influences the swimming dynamics of P. aeruginosa.