基于重水拉曼技术的氯己定对白色念珠菌 抑菌效能的研究

目的评价重水拉曼技术的普适性及氯己定(CHX)对白色念珠菌的抑菌效能。方法1)采用分光光度计测定吸光度值OD600,重水拉曼技术测定C?D ratio(重水峰所占比例)随时间的变化,探索重水对白色念珠菌生长的影响及该菌对重水的吸收规律,以评价重水拉曼技术的普适性。2)采用肉汤稀释法和重水拉曼技术,测定CHX对白色念珠菌的最低抑菌浓度(MIC)及最小代谢活性抑制浓度(MIC?MA),评价CHX对白色念珠菌生长及代谢的抑制效果。结果1)白色念珠菌在质量分数≤30%重水中,生长未受到明显抑制(P>0.05);白色念珠菌能活跃代谢重水并通过拉曼图谱检测,且C?D ratio与重水质量分数呈线性正相关关系(R^2=0.9894,P<0.05)。2)CHX对白色念珠菌的MIC为4μg·mL^-1,MIC?MA为8μg·mL^-1。在MIC下,白色念珠菌的生长受到完全抑制,但仍具有很高的代谢活性;只有达到2×MIC,即MIC?MA,该菌的代谢才能得到完全抑制。结论重水拉曼技术适用于评价药物对真菌代谢活性的影响,临床常用质量分数的CHX可完全抑制白色念珠菌的生长及代谢。

Antimicrobial effect of chlorhexidine on Candida albicans in vitro according to D2O-labeled single-cell Raman micro-spectroscopy

Objective To evaluate the universality of D2O-labeled single-cell Raman micro-spectroscopy and the bacteriostatic effect of chlorhexidine(CHX)on Candida albicans(C.albicans)in vitro.Methods The universality of D2Olabeled single-cell Raman micro-spectroscopy was investigated by exploring the growth of C.albicans under various doses of D2O and the regularity of D2O intake by C.albicans on the basis of the temporal change in OD600 and C-D ratio,respectively.Furthermore,we determined the effects of inhibiting the growth and CHX metabolism on C.albicans according to minimum inhibitory concentration(MIC)and minimum inhibitory concentration based on metabolic activity(MICMA)values,using broth dilution test and D2O-labeled single-cell Raman micro-spectroscopy,respectively.Results The growth of C.albicans was not significantly affected at concentrations below or equal to 30% D2O,and C.albicans can actively metabolize D2O,as indicated by Raman micro-spectroscopy results.Moreover,the C-D ratio of C.albicans at the stationary phase was positively correlated with D2O concentration.The MIC and MIC-MA of CHX were 4 and 8μg·mL^-1,respectively.Under the MIC,the growth of C.albicans was completely inhibited,but metabolic activity was active.Metabolic activity can be inhibited only when the concentration of 2×MIC was reached.Conclusion D2Olabeled single-cell Raman micro-spectroscopy is suitable for evaluating the metabolism activity of C.albicans.The commonly used concentration CHX in clinical practice effectively inhibits the growth and even the metabolism of C.albicans.