Sonodynamic effects of hematoporphyrin monomethyl ether on Staphylococcus aureus in vitro

This study aims to investigate the effect of hematoporphyrin monomethyl ether (HMME)-mediated sonodynamic antimicrobial chemotherapy (SACT) on Staphylococcus aureus. SACT was carried out using HMME and 1 MHz ultrasound irradiation. The bactericidal effect was evaluated by the counting colony-forming units (CFU), and important SACT parameters including ultrasound intensity and HMME concentration were determined. More than 95% of the bacteria colonies were effectively killed in the SACT group by 50 μg mL(-1) HMME combined with 6 W cm(-2) tone-burst ultrasound at 1 MHz, but this ultrasound level without HMME only reduced CFU by 38%. In the sonodynamic treatment, higher HMME concentrations and higher ultrasound intensities caused more death of bacteria. Incubation with different HMME concentrations without ultrasound showed no effect. Our results show that the HMME-mediated SACT can be significantly in killing S. aureus.