(368ai) Uncovering Bacterial-Mammalian Cell Interactions VIA Single-Cell Tracking

Research Interests: Biomolecular engineering, downstream and upstream process development, molecular biology, antibiotic tolerance, RNA therapeutics, Antibody therapeutics, cell and gene therapy.

Abstract

The interactions between bacterial pathogens and host cells are characterized by a multitude of complexities, leading to a wide range of heterogeneous outcomes. Despite extensive research, we still have a limited understanding of how bacterial motility in complex environments impacts their ability to tolerate antibiotics and adhere to mammalian cell surfaces. The challenge lies in unraveling the complexity of these interactions and developing informative metrics to predict the behavior of bacterial populations.

To address this challenge, we directed our efforts towards Pseudomonas aeruginosa, a pathogenic bacterium known for producing thick films in the lungs of cystic fibrosis patients. Single cell tracking revealed that P. aeruginosa exhibits diverse and complex interactions on mammalian cell surfaces, such as adhesion, rotational motion, and swimming, unlike the less interactive behavior of Escherichia coli. Our analysis indicated that P. aeruginosa demonstrated lower mean-squared displacement (MSD) values and greater adherence to mammalian cells compared to E. coli, which showed higher MSD slopes and less frequent adherence. Genetic mutations in P. aeruginosa resulted in altered displacement patterns and reduced adhesion, with the ΔfliD mutant displaying a more Gaussian displacement distribution and significantly less adherence to mammalian cells. This reduced adhesion correlated with decreased antibiotic tolerance, suggesting that adhesive bacteria might be less susceptible to antibiotics due to the protective environment provided by bacterial aggregation.

Overall, our findings underscore the importance of single cell tracking in accurately assessing bacterial behavior over short time periods and highlight its significant potential in guiding effective intervention strategies.