Inactivation of Planktonic Escherichia coli by Focused 1-MHz Ultrasound Pulses with Shocks: Efficacy and Kinetics Upon Volume Scale-Up |
| |
Authors: | Andrew A. Brayman Brian E. MacConaghy Yak-Nam Wang Keith T. Chan Wayne L. Monsky Valery P. Chernikov Sergey V. Buravkov Vera A. Khokhlova Thomas J. Matula |
| |
Affiliation: | 2. Tacoma Radiology Associates, Tacoma WA, USA;3. Department of Radiology, University of Washington, Seattle, WA, USA;4. Research Institute of Human Morphology, Laboratory of Cell Pathology, Moscow, Russia;5. Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow, Russia;6. Department of Acoustics, Physics Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia |
| |
Abstract: | This study addresses inactivation of E. coli in either 5- or 10-mL volumes, which were 50- to 100-fold greater than used in an earlier study (Brayman et al. 2017). Cells were treated with 1-MHz pulsed high-intensity focused ultrasound (10 cycles, 2-kHz repetition frequency, +65/–12.8 MPa focal pressures). The surviving fraction was assessed by coliform assay, and inactivation demonstrated curvilinear kinetics. The reduction of surviving fraction to 50% required 2.5 or 6 min in 5- or 10-mL samples, respectively. Exposure of 5 mL for 20 min reduced the surviving fraction to ~1%; a similar exposure of 10-mL samples reduced the surviving fraction to ~10%. Surviving cells from 5-min exposures appeared normal under light microscopy, with minimal debris; after 20 min, debris dominated. Transmission electron microscopy images of insonated samples showed some undamaged cells, a few damaged but largely intact cells and comminuted debris. Cellular damage associated with substantive but incomplete levels of inactivation can be variable, ranging from membrane holes tens of nanometers in diameter to nearly complete comminution. |
| |
Keywords: | Acoustic bacterial inactivation Focused ultrasound Pulsed HIFU Light microscopy of bacterial HIFU lysate Non-linear waveform distortion Planktonic bacterial inactivation Shock fronts TEM of bacterial HIFU lysate Ultrasonic bacterial inactivation |
本文献已被 ScienceDirect 等数据库收录! |
|