Sonodynamic action of hypocrellin B on methicillin-resistant Staphylococcus aureus.
Methicillin-resistant Staphylococcus aureus (MRSA) commonly causes refractory infections and has recently become a serious public health concern. The present study was designed to investigate sonodynamic action of hypocrellin B on MRSA. A MRSA strain (ATCC BAA-43) was used in the present study. The dark toxicity of hypocrellin B on MRSA and its uptake in MRSA first were measured. And then bacteria were incubated with hypocrellin B and exposed to ultrasound. After sonodynamic treatment, colony forming unit assay and bacterial viability assay were conducted. Membrane permeability assay, DNA fragmentation assay, and DNA synthesis assay were also performed to examine the underlying mechanism. The results showed that hypocrellin B at concentrations of up to 500 μM had no toxicity to MRSA in the dark. After incubation for 50 min, hypocrellin B could be maximally absorbed by MRSA, and exhibited significant sonodynamic activity in a dose-dependent manner. The 5-log reduction in colony forming unit (CFU) was observed after hypocrellin B (40 μM) treatment at an intensity of 1.38 W/cm(2) ultrasound for 5 min. Compared to the control, hypocrellin B alone and ultrasound sonication alone group, more dead cells were found and bacterial membrane integrity was notably damaged after sonodynamic treatment of hypocrellin B. However, no remarkable DNA damage was found in MRSA after sonodynamic treatment of hypocrellin B. All the findings demonstrated that hypocrellin B could serve as a potential antibacterial sonosensitizer to significantly cause damage to the membrane integrity of MRSA and inhibit its growth under ultrasound sonication.
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
Xinna
X
Wang
Department of Microbiology, Faculty of Medicine, The Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
Margaret
M
Ip
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address: awnleung@cuhk.edu.hk.
Albert Wingnang
AW
Leung
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
Pan
P
Wang
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
Hongwei
H
Zhang
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
Heyu
H
Hua
School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address: csxu@cuhk.edu.hk.
Chuanshan
C
Xu
D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D053672:Electrochemotherapy / Q000379:methods*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D010569:Perylene / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011809:Quinones / Q000008:administration & dosage*; D011829:Radiation Dosage; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage; D013010:Sonication / Q000379:methods*; D013242:Sterilization / Q000379:methods*
D011809:Quinones; D011838:Radiation-Sensitizing Agents; D010569:Perylene; C064522:hypocrellin B
Drug-resistant bacteria; Hypocrellin B; Sonodynamic antibacterial chemotherapy; Sonodynamic inactivation; Staphylococcus aureus; Traditional Chinese medicines