Periodically Distrubing the Spatial Structure of a Microbial Community Composed of Pseudomonas aeruginosa and Staphylococcus aureus Determines its Composition
Abstract
Pseudomonas aeruginosa and Staphylococcus aureus can co-occur in chronic and hard-to-treat infections. They interact through several small diffusible molecules and enzymes which increase their virulence, growth rates, and antibiotic resistance. Previous work has shown that the spatial structure of microbial communities in continuously mixed environments and completely undisturbed environments affects bacterial interactions. These extreme cases fail to fully represent a natural environment where the spatial structures developed by the microbes are periodically disturbed. The objective of this study is to determine how periodic perturbations to spatial structures affects the interaction and co-existence of P. aeruginosa and S. aureus in co-culture. We found that in two extreme cases of disturbance, a continuously disturbed environment and a completely undisturbed environment, the microbial community was dominated by P. aeruginosa. Periodically disturbing the spatial structure of the population shifted dominance to S. aureus, which was consistent when the initial density of the populations were changed. Moreover, we found that the initial ratio of P. aeruginosa and S. aureus determines the ability of the latter to dominate the population. Agent based modeling suggests that interactions between competition for nutrition and antagonistic small diffusible molecules can explain this trend. Our results highlight how periodic changes to spatial structure can affect microbial community composition and may lead to new approaches to treat infections.
Faculty Sponsors
Dr. Omar T. Eldakar, Dr. Robert Smith
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2021 12:00 PM
End Date
4-9-2021 12:00 PM
Periodically Distrubing the Spatial Structure of a Microbial Community Composed of Pseudomonas aeruginosa and Staphylococcus aureus Determines its Composition
Alvin Sherman Library
Pseudomonas aeruginosa and Staphylococcus aureus can co-occur in chronic and hard-to-treat infections. They interact through several small diffusible molecules and enzymes which increase their virulence, growth rates, and antibiotic resistance. Previous work has shown that the spatial structure of microbial communities in continuously mixed environments and completely undisturbed environments affects bacterial interactions. These extreme cases fail to fully represent a natural environment where the spatial structures developed by the microbes are periodically disturbed. The objective of this study is to determine how periodic perturbations to spatial structures affects the interaction and co-existence of P. aeruginosa and S. aureus in co-culture. We found that in two extreme cases of disturbance, a continuously disturbed environment and a completely undisturbed environment, the microbial community was dominated by P. aeruginosa. Periodically disturbing the spatial structure of the population shifted dominance to S. aureus, which was consistent when the initial density of the populations were changed. Moreover, we found that the initial ratio of P. aeruginosa and S. aureus determines the ability of the latter to dominate the population. Agent based modeling suggests that interactions between competition for nutrition and antagonistic small diffusible molecules can explain this trend. Our results highlight how periodic changes to spatial structure can affect microbial community composition and may lead to new approaches to treat infections.
