ChBE Spring 2018 Seminar, Speaker Dr. Philip Stewart

Armour College of Engineering's Chemical and Biological Engineering Department will host a seminar featuring Professor of Chemical and Biological Engineering, Center for Biofilm Engineering at Montana State University, Dr. Philip Stewart. He will present his lecture, Biofilm Infections on Medical Devices.

Bacteria that colonize the surface of indwelling medical devices such as catheters or prosthetic joints can establish slow-moving yet persistent infections. Once the microorganisms form a biofilm, they become protected from killing by antiseptics, antibiotics, and the body’s innate immune defenses. Protective mechanisms in biofilms include incomplete antimicrobial penetration and dormancy of a subpopulation of microbial cells. Both mechanisms derive from reaction-diffusion interactions that are amenable to engineering analysis. Because established biofilms are so recalcitrant to chemotherapy, approaches to preventing biofilm formation are sought. An alternative and still unexplored strategy is to guide or boost the host defenses around the implanted device to eliminate contaminating bacteria. This strategy is partly inspired by recent stunning progress with immunotherapeutic approaches for treating cancer. To investigate the factors that govern immune cell efficacy on an abiotic surface, the ability of human neutrophils to clear newly attached S. aureus bacteria from a serum-coated glass surface was examined in vitro using time-lapse confocal scanning laser microscopy and quantitative image analysis. Results show that the ratio of the surface concentrations of neutrophils and bacteria and the time required to recruit neutrophils to the surface are critical parameters affecting the potential of host defenses to eradicate nascent biofilm. Ultimately, such research could lead to a new generation of immunomodulatory biomaterials that direct and enhance the ability of innate immune cells to prevent infections associated with implanted medical devices.

Biography:

Dr. Stewart is a Chemical and Biological Engineering Professor at the Center for Biofilm Engineering at Montana State University. He holds degrees in Chemical Engineering from Rice University and Stanford University. His research focuses on the control of detrimental microbial biofilms and strategies for preventing biofilm infections. Dr. Stewart has been integrally involved with the Center for Biofilm Engineering since his arrival on the Montana State campus, serving as director from 2005 to 2015.