Department of Laboratory Medicine and Pharmacy, Suzhou Health College, Suzhou, China.
Lett Appl Microbiol. 2011 Oct;53(4):409-16. doi: 10.1111/j.1472-765X.2011.03122.x. Epub 2011 Aug 8.
To investigate the antibiofilm effect of cinnamaldehyde on methicillin-resistant Staphylococcus aureus (MRSA) and analyse the effect of subminimum inhibitory concentrations (MICs) of cinnamaldehyde on the expression of the biofilm-related gene sarA.
The MICs and minimum bactericidal concentrations (MBCs) were determined using a microtitre broth dilution method. Biofilm susceptibility was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining and colony forming unit (CFU) counting assays. Antibiofilm effects were studied with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). SarA expression was assessed by real-time PCR. MICs and MBCs were in the range 0.0625-0.5% (v/v). The killing effects were concentration dependent. At a concentration of 5× MIC, all strains in biofilm were decreased to lower than 20% of the control groups. SEM and CLSM images indicated that a 5× MIC concentration of cinnamaldehyde was able to detach and kill existing biofilms. Apart from strain JB-06, real-time PCR showed that the expression of sarA of all other strains was decreased upon exposure to sub-MICs of cinnamaldehyde.
These data showed the strong killing effect of cinnamaldehyde against MRSA within biofilms.
This study indicated the potential of cinnamaldehyde as an inhibitory agent for use in MRSA biofilm-related infections.
研究肉桂醛对耐甲氧西林金黄色葡萄球菌（MRSA）的抗生物膜作用，并分析亚最小抑菌浓度（MIC）肉桂醛对生物膜相关基因 sarA 表达的影响。
采用微量肉汤稀释法测定 MIC 和最小杀菌浓度（MBC）。采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）染色和菌落形成单位（CFU）计数法测定生物膜易感性。通过扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）研究抗生物膜作用。通过实时 PCR 评估 SarA 表达。MIC 和 MBC 范围为 0.0625-0.5%（v/v）。杀菌效果呈浓度依赖性。在 5×MIC 浓度下，所有生物膜中的菌株均减少至低于对照组的 20%。SEM 和 CLSM 图像表明，5×MIC 浓度的肉桂醛能够分离和杀死现有的生物膜。除了 JB-06 株外，实时 PCR 显示所有其他菌株在接触亚 MIC 肉桂醛后 sarA 的表达均降低。
这些数据表明肉桂醛对生物膜内耐甲氧西林金黄色葡萄球菌具有很强的杀菌作用。
本研究表明肉桂醛作为一种抑制物在治疗耐甲氧西林金黄色葡萄球菌生物膜相关感染方面具有潜力。
