This research is centered on the elucidation of the mechanisms involved in the recently discovered strong synergistic effect between ultrasound irradiation and antibiotic therapy on bacterial cell killing in-vitro. Preliminary results have been published Pitt et al. 1994 and a US patent application was filed by Dr. W.G. Pitt (University of Utah) for the Antimicrobial Delivery to Bacterial Biofilms. However, the mechanism producing this important and promising phenomenon is unclear. In the present project EPR technology is being applied to monitor the effect of ultrasound on 1) biofilm permeability and 2) trans- membrane transport into cells of two paramagnetic compounds (Tempone and 16-doxylstearate) and a spin-labeled antibiotic carboxy-proxyl-gentamicin. Pseudomonas aeruginosa are used as a model bacterium. The effect of ultrasonic irradiation of various frequencies and intensities on the permeability of bacterial biofilms will be monitored using a specially designed permeation cell. The possible disruption of bacterial cell membranes, changes in lipid bilayer structure, permeability of cell membranes to paramagnetic probes and antibiotic as well as their partitioning between the membranes and cytoplasm will be monitored by EPR as a function of the ultrasound frequently and intensity. Interactive activities include: teaching a junior level course in materials science, and a graduate course entitled "Environmental Issues in Polymer Technology"; lecturing in the departments of Chemical Engineering, Chemistry, and Physics; serving as an ad hoc member of the committee that administers Brigham Young University's Women in Science Center; and speaking on past and present life in Russia and about her friend and colleague, Audrey Sakharov.
