Life Sciences Commons^™

Bacterial Stress Responses To 1-Megahertz Pulsed Ultrasound In The Presence Of Microbubbles, Amy Cheng Vollmer, Sylvia D. Sakyiama Kwakye , '98, Matthew Evan Halpern , '98, E. Carr Everbach

Engineering Faculty Works

Members of a panel of stress-responsive biosensors have been used to study the effect of megahertz frequency ultrasound onEscherichia coli. Insonification causes acoustic cavitation, the collapse of oscillating microbubbles in solution, which can damage bacterial cells. A focused 1-MHz ultrasound transducer, capable of generating a spatial peak pulse average intensity of 500 W/cm2, was used to treat liquid bacterial cultures. Stress-responsive promoters fused to luxCDABE allowed the continuous measurement of light produced as a result of protein damage, DNA damage, oxidative stress, and membrane perturbation. A promoter responsive to ammonia limitation was not transcriptionally activated under test conditions. In contrast …