阿奇霉素对金黄色葡萄球菌生物被膜的抑制作用

Inhibition of azithromycin on biofilms of Staphylococcus aureus

金黄色葡萄球菌(S.aureus)是感染性疾病常见病原体之一,具有较高的发病率和病死率。采用微量稀释法测定阿奇霉素对S.aureus悬浮菌和生物被膜的抗菌活性,并通过生物被膜形成实验、溶血素检测、Western blot分析和荧光定量PCR实验考察了阿奇霉素对S.aureus生物被膜形成和主要毒力因子分泌的影响。结果表明:阿奇霉素对S.aureus悬浮菌和生物被膜具有较好的抗菌活性,并可有效地抑制生物被膜的形成;亚抑菌浓度的阿奇霉素呈剂量依赖式抑制S.aureusα-溶血素和肠毒素A的分泌,1/2MIC时其分泌几乎完全受到抑制,这将有助于治疗由S.aureus导致的感染。

Staphylococcus aureus is one of the most common pathogens of infectious diseases with a significant morbidity and mortality.Antimicrobial activity of azithromycin against S.aureus were determined for each microorganism grown in suspension or biofilm using microbroth dilution method,and influence of azithromycin on biofilm formation and secretion of virulence factors by S.aureus was assessed by biofilm formation assay,hemolysin assay,Western blot and real-time RT-PCR.The results showed that azithromycin had better antimicrobial activity against S.aureus grown in suspension or biofilm,and effective inhibition of biofilm formation;subinhibitory concentration of azithromycin reduced the production of α-haemolysin and enterotoxin A by S.aureus in dosedependent manner.In particular,1/2MIC of azithromycin almost completely suppresses the production of α-haemolysin and enterotoxin A.This study might be especially helpful for the treatment of S.aureus infections.