Inactivation of gram positive or gram negative microbes using different histotripsy regimes

Abstract

Abscesses are infected walled-off collections of pus and bacteria. They can affect any part of the body. Current treatment is typically limited to antibiotics, catheter drainage and hospitalization, or surgical wash-out. Although bacteria can develop drug resistance, they remain susceptible to thermal and mechanical damage. Histotripsy generates localized cavitation without heating and represents a potential new noninvasive treatment modality. Successful histotripsy treatments were demonstrated with gram-negative E-coli in both in vitro and in vivo studies [Brayman et al., UMB 44, 1996–2008 (2018); Matula et al., UMB 47, 603–619 (2020)]. Interestingly, preliminary data showed that boiling histotripsy was less effective than cavitation histotripsy in killing bacteria. In this talk, we will describe more in-depth studies that compare cavitation histotripsy (low number of cycles, high-pulse repetition rate) with boiling histotripsy (high number of cycles, low-pulse repetition rate) on inactivation rates of microbes. [Work funded in part by NIH NIBIB No. R01EB019365.]