HIGH INTENSITY FOCUSED ULTRASOUND (HIFU) HEATING IMPROVES PERFUSION AND ANTIMICROBIAL EFFICACY IN MOUSE &ITSTAPHYLOCOCCUS&IT ABSCESS

Chronic wounds typically require long-duration treatment with a combination of antibiotics administered systemically. This incurs adverse side effects and can require aversive surgical treatments and limb amputations. To improve non-invasive antimicrobial therapy, the objective of this study was to investigate antimicrobial chemotherapy combined with high-intensity focused ultrasound (HIFU) heating (HT). A Staphylococcus aureus abscess (80 +/- 30 mm(3)) was generated in the mouse Hank region. Once the average temperature (similar to 42 degrees C-46 degrees C) in the abscess was reached with HIFU-HT, a broad-spectrum antimicrobial (ciprofloxacin, 10 mg/kg) and perfusion marker (Evans blue dye, 40 mg/kg wt) were administered intravenously via the tail vein. Four hours later, mean abscess perfusion and colony-forming units (CFUs) per gram of abscess were determined. HIFU-HT increased abscess perfusion by similar to 2.5-fold (4 +/- 0.6 mu g/mL Evans blue) compared with control (1.5 +/- 0.7 mu g/mL), and improved antimicrobial efficacy to decrease percentage average survival of S. aureus by similar to 20% (46 +/- 7 CFUs/g of abscess) versus that seen with ciprofloxacin alone (61 +/- 4 CFU/g). Our in vivo data suggest that HIFU-HT can improve antimicrobial treatment responses against deep-seated bacteria in abscess wounds via enhanced perfusion. (C) 2018 World Federation for Ultrasound in Medicine & Biology. All rights reserved.