不同浓度酒精对两种常见细菌生物膜的影响

Effects of different alcohol concentrations on the biofilms of two common bacteria

目的探讨不同浓度的酒精对金黄色葡萄球菌和大肠杆菌生物膜形成的抑制作用。方法配制不同浓度的酒精(1.25%、2.5%、5%和10%),作用于培养24 h形成成熟生物膜的金黄色葡萄球菌和大肠埃希菌,利用FDA/PI荧光染料染色,在激光共聚焦显微镜扫描生物膜并分析活菌与死菌比例。结果不同浓度的酒精对两种细菌生物膜的形成均有一定破坏作用,5%、10%浓度酒精对金黄色葡萄球菌生物膜破坏最大,活菌与死菌比例为0.142±0.007、0.006±0.001;10%浓度酒精对大肠埃希菌生物膜破坏最大,活菌与死菌比例为5.751±1.779。结论较低浓度的酒精可抑制金黄色葡萄球菌和大肠埃希菌生物膜的形成,且10%浓度的酒精效果最好。

Objective To study the effects of different alcohol concentrations against the biofilms of Staphylococcus aureus and Escherichia coli. Methods Different concentrations of alcohol （ 1.25%, 2.5%, 5% and 10% ） were used to treat Staphylococcus aureus and Escherichia coli with biofilm after cultivated for 24 hours. The ratio of viable vs inactive organisms was analyzed by FDA/PI fluoresce- in staining through confocal microscopy scanning. Results Different concentrations of alcohol brought a certain degree of destroy to the biofilms. 5% and 10% concentrations caused the most severe damage to the biofilm of Staphylococcus aureus, with the ratio of viable vs. inactive organisms being 0. 142 ± 0. 007 and 0. 006 ± 0.001 respectively. 10% of alcohol acutely destroyed the biofilm of Escherichia coli, with the ratio of viable vs. inactive organisms being 5.751±1. 779. Conclusion Lower concentration of alcohol inhibits the formation of biofilms of Staphylococcus aureus and Escherichia coli more effectly, with the optimal concentration being 10%.