Discipline: Biological Sciences
Qaleelah Smith - Bennett College
Co-Author(s): Nhu Nguyen and Yann Dufour, Michigan State University, Lansing, MI
Mucus – mainly composed of mucins (sugar proteins) – is located on the lining of internal organs and protects epithelial cells by preventing bacteria and other pathogens from moving through. Mucus must be permeable enough for nutrients to go through, yet impermeable to opportunistic bacteria that try to penetrate, colonize, and infect the mucus layer. Bacterial pathogens can compromise the mucus layer to access and infect epithelial cells. Previous studies have shown that flagellar motility is an important virulence factor because when motility is disrupted virulence will decrease in many pathogenic bacteria. Mucus is a viscoelastic material and its characteristics can be measured using rheology. To obtain a better understanding of how mucus prevents bacterial motility, I will investigate the viscous and elastic components independently from each other. My hypothesis is that by exposing Escherichia coli to various viscous environments, there will be an evident change in the speed and directional persistence of the cells. The viscosity of the environment will be changed using different concentrations of polyvinylpyrrolidone (PVP). Viscosity will be measured by using single-particle tracking video-microscopy to calculate the diffusion coefficient of micro-beads and the viscosity of the environment. The behavior of Escherichia coli in different viscosity will also be characterized using single-particle tracking and computer analysis. Direct and detailed observations of how motile bacteria navigate viscoelastic environments will help us understand how pathogens compromise the mucosal defense and can help us design strategies to prevent bacterial infections.
Funder Acknowledgement(s): I wish to thank the following people for their help on the project: Nhu Nguyen and Yann Dufour. Also, all the BEACON/SROP Program Faculty & Facilitators.
Faculty Advisor: Hyunju Oh, email@example.com
Role: I executed a number of experiments that expanded my knowledge of microbiology and contributed to my research project. My goal was to expose Escherichia coli to various viscous environments and observe the changes in speed and directional persistence of the cells. I manipulated the viscosity of the environment using different concentrations of polyvinylpyrrolidone (PVP). Viscosity was measured by using single-particle tracking video-microscopy to calculate the diffusion coefficient of micro-beads and the viscosity of the environment. The behavior of Escherichia coli in different viscosity was characterized using single-particle tracking and computer analysis.