摘要
目的研究人抗菌肽LL-37对耐甲氧西林金黄色葡萄球菌(MRSA)生物膜的相关作用,为MRSA的预防治疗以及新药物开发应用提供新策略。方法运用微量肉汤稀释法测定LL-37对临床MRSA菌株的最小抑菌浓度;建立96孔板及6孔板生物膜体外模型;通过结晶紫定量法以及激光共聚焦荧光染色法检测LL-37对MRSA生物膜形成的影响。结果微量肉汤稀释法测得LL-37对临床MRSA菌株的MIC为12.5μmol/L。不同浓度LL-37作用后,结晶紫定量法结果表明1/20 MIC亚抑菌浓度的LL-37即可抑制生物膜形成(P<0.01),且抑制率随用药浓度增加也随之提高,在1/4 MIC条件下生物膜形成抑制率可达到63%。与生理盐水对照组相比,激光共聚焦扫描显微镜下可见,用药组生物膜排列稀疏,厚度变薄,组成菌量明显减少。结论低浓度的LL-37能够抑制MRSA生物膜的形成,并且对成熟生物膜结构也具有一定的破坏作用。
Objective To investigate the effect of human cathelicidin antibacterial peptide LL-37 on biofilm formation of methicillin-resistant Staphylococcus aureus（ MRSA）, and provide a new strategy for clinical prevention and treatment of drug-resistant biofilm infection.Methods The minimal inhibitory concentration of LL-37 was determined by broth microdilution assay.The model of MRSA biofilms in vitro was established in 96- and 6-well plates.The biofilm production was quantified by crystal violet and the biofilm morphology was observed by confocal laser scanning microscopy（ CLSM）.Results The minimal inhibitory concentration of LL-37 was 12.5 μmol/L.The model of MRSA biofilms in vitro was successfully established.LL37 treatment inhibited the attachment and biofilm formation of MRSA in a dose-dependent way.A low concentration of LL37（ 1/20 MIC） decreased the biofilm formation of MRSA,and even the inhibition rate of1/4 MIC reached to 63%.After LL-37 treatment,the bacterial biofilm mass was significantly reduced and the biofilm was thinner and looser observed by CLSM.Conclusion LL37 with a low concentration far below MIC may decrease the bacteria attachment and the biofilm mass in vitro.
出处
《广东药学院学报》
CAS
2016年第4期498-502,共5页
Academic Journal of Guangdong College of Pharmacy
基金
广州医科大学青年科研项目(2013A09)
