Inactivation of bacteria using histotripsy: A step toward the treatment of abscesses Free

Abscesses are walled-off collections of pus and bacteria that commonly require invasive treatments. Abdominal abscesses in particular rank among the top diseases requiring rehospitalization. Thus, abscesses represent a ubiquitous global healthcare problem. The long-term goal of this work is to investigate histotripsy as a noninvasive alternative to eradicate bacteria in situ. In our previous work, the inactivation of Escherichia coli (E. coli) was evaluated at different histotripsy parameters, including peak negative pressure, pulse length, and treatment time. This study investigates the frequency dependence of E. coli inactivation in vitro. We also report on preliminary studies to use histotripsy on a large ex vivo porcine abscess. The in vitro studies consisted of 10 mL E. coli suspensions treated at three frequencies (0.81 MHz, 1.20 MHz, and 3.25 MHz). In vitro treatment results showed a decreasing trend of E. coli inactivation with increasing frequency. The ex vivo abscess was treated at 1.5 MHz, 1 ms pulse duration, and 10 Hz pulse repetition frequency (PRF). Ex vivo studies showed a reduction in viscosity post-treatment suggesting the abscesses can be liquefied.