title: Sonodynamic inactivation of methicillin-resistant Staphylococcus aureus in planktonic condition by curcumin under ultrasound sonication.
abstract: Methicillin-Resistant Staphylococcus aureus (MRSA) is an important cause of difficult-to-treat infections. The present study aims to investigate sonodynamic inactivation of MRSA in planktonic condition using curcumin under ultrasound sonication. Dark toxicity of curcumin to MRSA was investigated to choose the concentration range of curcumin used in the study. The uptake of curcumin in MRSA was observed before ultrasound sonication. After sonication colony forming units (CFUs) and bacterial viability were investigated using fluorescence assay. Additionally, chromosomal DNA fragmentation was also analyzed. Curcumin showed no dark toxicity to MRSA in the concentration range of⩽500μM. The maximum uptake of curcumin in MRSA occurred in 50min after curcumin incubation. Counting of CFUs showed that curcumin had significantly sonodynamic killing effect on MRSA in a curcumin dose-dependent manner, and 5-log reduction in CFU was observed after curcumin treatment (40μM) at room temperature in the dark for 50min followed by exposure to ultrasound with intensity of 1.56W/cm(2) for 5min. The ratio of green-fluorescent intensity to red-fluorescent intensity was obviously decreased after curcumin treatment under ultrasound sonication. No significant change in chromosomal DNA was found in the cultured MRSA after the combined treatment of curcumin and ultrasound. These results demonstrated that sonodynamic action of curcumin had significant inactivation of MRSA in planktonic condition.
authors: School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Xinna
authors: X
authors: Wang
authors: Department of Microbiology, Faculty of Medicine, The Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Margaret
authors: M
authors: Ip
authors: School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Albert Wingnang
authors: AW
authors: Leung
authors: School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China. Electronic address: csxu@cuhk.edu.hk.
authors: Chuanshan
authors: C
authors: Xu
mesh_terms: D015169:Colony Count, Microbial; D003474:Curcumin / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D010933:Plankton; D013010:Sonication
chemical_list: D003474:Curcumin
keywords: Curcumin; MRSA; Planktonic bacteria; Sonodynamic chemotherapy; Sonodynamic inactivation