Yan Xin, Gu Shanshan, Shi Yunjia, Cui Xingyang, Wen Shanshan, Ge Junwei
College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
Arch Microbiol. 2017 Nov;199(9):1267-1275. doi: 10.1007/s00203-017-1396-8. Epub 2017 Jun 14.
Staphylococcus aureus (S. aureus) is a Gram-positive pathogen and forms biofilm easily. Bacteria inside biofilms display an increased resistance to antibiotics and disinfectants. The objective of the current study was to assess the antimicrobial activities of emodin, 1,2,8-trihydroxy-6-methylanthraquinone, an anthraquinone derivative isolated from Polygonum cuspidatum and Rheum palmatum, against S. aureus CMCC26003 grown in planktonic and biofilm cultures in vitro. In addition, a possible synergistic effect between emodin and berberine chloride was evaluated. As quantified by crystal violet method, emodin significantly decreased S. aureus biofilm growth in a dose-dependent manner. The above findings were further supported by scanning electron microscopy. Moreover, the present study demonstrated that sub-MICs emodin obviously intervened the release of extracellular DNA and inhibited expression of the biofilm-related genes (cidA, icaA, dltB, agrA, sortaseA and sarA) by real-time RT-PCR. These results revealed a promising application for emodin as a therapeutic agent and an effective strategy to prevent S. aureus biofilm-related infections.
金黄色葡萄球菌是一种革兰氏阳性病原体，很容易形成生物膜。生物膜内的细菌对抗生素和消毒剂表现出更高的抗性。本研究的目的是评估大黄素（一种从虎杖和掌叶大黄中分离出的蒽醌衍生物，即1,2,8 - 三羟基 - 6 - 甲基蒽醌）对体外浮游和生物膜培养的金黄色葡萄球菌CMCC26003的抗菌活性。此外，还评估了大黄素与盐酸小檗碱之间可能的协同作用。通过结晶紫法量化，大黄素以剂量依赖的方式显著降低了金黄色葡萄球菌生物膜的生长。扫描电子显微镜进一步支持了上述发现。此外，本研究表明，亚抑菌浓度的大黄素通过实时逆转录聚合酶链反应明显干预了细胞外DNA的释放，并抑制了生物膜相关基因（cidA、icaA、dltB、agrA、分选酶A和sarA）的表达。这些结果揭示了大黄素作为一种治疗剂的潜在应用前景，以及预防金黄色葡萄球菌生物膜相关感染的有效策略。
