(293e) Microsphere Hydrogel Encapsulation to Identify Interactions in Chronic Wound Microbial Consortia

Authors: 
Pratt, S. - Presenter, Montana State University
Chang, C., Montana State University
Russell, P., Montana State University
Most bacterial cells are members of diverse microbial communities. Community life allows for chemical and physical interactions that give rise to emergent traits such as antibiotic resistance, increased biomass production, or the expansion of tolerable growth environments. Community-associated traits play a detrimental role in chronic infections, such as cystic fibrosis lung infections, diabetic foot ulcers, and chronic rhinosinusitis, all of which are frequently caused by a polymicrobial consortia. Understanding how microbial interactions lead to observable traits in pathogenic communities is important in developing treatments for chronic infections of the human body. An especially ubiquitous and potent pathogenic consortium in chronic infections is that of Pseudomonas aeruginosa and Staphylococcus aureus. Preliminary research has identified emergent traits in this community related to pathogenicity. We aim to probe species-species interactions to further identify the emergent traits of P. aeruginosa and S. aureus consortia. These studies are conducted by encapsulating bacteria in chemically permeable hydrogel microspheres. Cells in the microspheres are physically, but not chemically, isolated. Comparing systems that allow only chemical interactions to systems that allow both physical and chemical interactions, such as bulk growth or co-encapsulation, tests the role of both interaction types. The test systems are probed metabolically and genetically. When coupled with the ability to monitor single cell growth using confocal laser scanning microscopy, and to expose cells to stresses such as oxygen limitation and antibiotic treatment, we can relate interactions to observed changes in growth and stress response. Thus, by applying a novel microsphere hydrogel system to the study of P. aeruginosa and S. aureus, we can begin to unravel the relationships between interactions and pathology in P. aeruginosa and S. aureus communities.