The specific anti-biofilm effect of gallic acid on Staphylococcus aureus by regulating the expression of the ica operon
The specific anti-biofilm effect of gallic acid on Staphylococcus aureus by regulating the expression of the ica operon
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没食子酸通过调节ica操纵子表达对金黄色葡萄球菌的特异性抗生物膜作用
DOI：
10.1016/j.foodcont.2016.09.015
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发表时间：
2017-03-01
期刊：
影响因子：
6
通讯作者：
Du, Xiaodan
中科院分区：
文献类型：
--
作者：
Liu, Meihui;Wu, Xiaoxia;Du, Xiaodan
金黄色葡萄球菌(S.aureus)生物膜在食品安全方面具有重要意义，因为生物膜可以增加食品污染的风险，增强细菌的致病性。ICA编码的多糖胞间黏附素(PIA)在生物膜的形成中起着重要作用。在本研究中，没食子酸在悬液中对金黄色葡萄球菌的MIC为2 mg/m L，在生物膜中的MIC为4 mg/m L。生物被膜的定量结晶紫染色显示，2 mg/mL的没食子酸能有效地抑制生物被膜的形成，环境扫描电子显微镜图像清楚地显示了金黄色葡萄球菌的三维生物被膜形态和由此产生的抗生物被膜效应。对生物膜中活菌的检测表明，没食子酸渗透生物膜对金黄色葡萄球菌有杀灭作用，对生物膜细菌的杀菌效果与浮游细菌相当。我们进一步探讨了没食子酸对金黄色葡萄球菌生物膜形成过程中ICA家族基因表达和多糖黏液形成的影响。结果表明，随着没食子酸浓度的增加，ICaA和iCAD的表达呈剂量依赖性下调，而iCab和ICac的表达无明显变化。减少了多糖粘液的形成。根据这些结果，没食子酸作为一种天然物质，可能在食品工业中发挥重要作用。(C)2016爱思唯尔有限公司。保留所有权利。
Staphylococcus aureus (S. aureus) biofilms are of considerable interest in food safety because biofilms can increase the risk of food contamination and enhance the pathogenicity of bacteria. The ica-encoded polysaccharide intercellular adhesin (PIA) plays an important role in biofilm formation. In this study, the MIC of gallic acid against S. aureus in suspension and in biofilms was 2 mg/mL and 4 mg/mL, respectively. Quantitative crystal violet staining of biofilms showed that 2 mg/mL gallic acid can effectively inhibit biofilm formation and the ESEM images clearly showed the three-dimensional biofilm morphology of the S. aureus and the resulting anti-biofilm effect. The determination of viable bacteria in the biofilm revealed that gallic acid penetrated the biofilm to kill S. aureus, the bactericidal effect on the biofilm bacteria was comparable to that of planktonic bacteria. We further explored the influence of gallic acid on ica family gene expression and polysaccharide slime formation in S. aureus biofilm formation. The results showed that icaR was significantly activated that; icaA and icaD were downregulated in a dose dependent manner with increasing concentrations of gallic acid; however, the expression of icaB and icaC was not significantly affected. The polysaccharide slime formation was reduced as well. Based on these results, gallic acid, as a natural substance, may play an important role in the food industry. (C) 2016 Elsevier Ltd. All rights reserved.