The antibacterial mechanism of oridonin against methicillin-resistant Staphylococcus aureus (MRSA)

Pharmaceutical Biology

Xu Song¹  Zhongqiong Yin¹  Hualin Fu¹  Tayyab Rehman¹  Changliang He¹  Kexin Gu¹  Zhongwei Yuan¹  Zhixiang Yuan¹  Gang Shu¹  Lizi Yin¹  Juchun Lin¹  Tianyi Zhang¹  Yuanfeng Zou¹  Lixia Li¹  Xiaoxia Liang¹  Ping Ouyang¹ 

[1] College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, Chin;

关键词: Bacteriostat;    cell membrane;    cell wall;    protein metabolism;    LDH;    DNA;    microscopic structure;   

DOI  :  10.1080/13880209.2019.1674342

来源: Taylor & Francis

【 摘 要 】

Context: Methicillin-resistant Staphylococcus aureus (MRSA) is a very harmful bacterium. Oridonin, a component in Rabdosia rubescens (Hemsl.) Hara (Lamiaceae), is widely used against bacterial infections in China.Objective: We evaluated oridonin effects on MRSA cell membrane and wall, protein metabolism, lactate dehydrogenase (LDH), DNA and microscopic structure.Materials and methods: Broth microdilution and flat colony counting methods were used to measure oridonin minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against USA300 strain. Electrical conductivity and DNA exosmosis were analysed to study oridonin effects (128 μg/mL) on cell membrane and wall for 0, 1, 2, 4 and 6 h. Sodium dodecyl sulphate polyacrylamide gel electrophoresis was used to detect effects on soluble protein synthesis after 6, 10 and 16 h. LDH activity was examined with an enzyme-linked immunosorbent assay. Effects of oridonin on USA300 DNA were investigated with DAPI staining. Morphological changes in MRSA following oridonin treatment were determined with scanning electron microscopy (SEM) and transmission electron microscopy (TEM).Results: Oridonin MIC and MBC values against USA300 were 64 and 512 μg/mL, respectively. The conductivity and DNA exosmosis level of oridonin-treated USA300 improved by 3.20±0.84% and increased by 58.63 ± 1.78 μg/mL, respectively. LDH and soluble protein levels decreased by 30.85±7.69% and 27.51 ± 1.39%, respectively. A decrease in fluorescence intensity was reported with time. Oridonin affected the morphology of USA300.Conclusions: Oridonin antibacterial mechanism was related to changes in cell membrane and cell wall permeability, disturbance in protein and DNA metabolism, and influence on bacterial morphology. Thus, oridonin may help in treating MRSA infection.

【 授权许可】

CC BY