苦参总碱对无乳链球菌、粪肠球菌和白假丝酵母菌增殖影响的体外观察研究

Effects of Sophora flavescens alkaloids on the proliferation of Streptococcus agalactiae, Enterococcus faecalis and Candida albicansin in vitro

目的:研究苦参总碱对女性下生殖道几种常见致病菌(无乳链球菌、粪肠球菌和白假丝酵母菌)体外增殖的影响以及对白假丝酵母菌生物膜形成的影响。方法:体外培养无乳链球菌、粪肠球菌和白假丝酵母菌,通过琼脂板稀释法制备菌板,检测不同浓度苦参总碱对无乳链球菌、粪肠球菌和白假丝酵母菌的最小抑菌浓度(MIC);通过结晶紫染色法和共聚焦显微成像检测苦参总碱对白假丝酵母菌生物膜形成的影响;通过扫描电镜成像法观察苦参总碱对生物膜形成和菌落形态的影响。结果:苦参总碱对无乳链球菌、粪肠球菌和白假丝酵母菌的MIC分别为16,32,32 mg·mL-1。苦参总碱质量浓度1 mg·mL-1时对白假丝酵母菌生物膜的形成有明显的抑制作用(P<0.05),且抑制程度呈浓度依赖性,浓度越高,对生物膜的抑制作用越明显。同时,电镜下亦可见随着苦参总碱浓度的升高,白假丝酵母菌不仅生物膜形成受到抑制,且菌丝形成受到阻断,菌落中菌丝变短、菌丝间连接变疏松。结论:苦参总碱(16,32,32 mg·mL-1)对无乳链球菌、粪肠球菌和白假丝酵母菌的增殖均有抑制作用,且能抑制白假丝酵母菌生物膜形成,阻断酵母-菌丝二相性转换,对进一步探索苦参总碱治疗阴道炎,减少复发的临床应用具有重要意义。

OBJECTIVE To explore the effects of Sophora flavescens alkaloids on the proliferation of several common pathogenic bacteria(Streptococcus agalactiae,Enterococcus faecalis and Candida albicans)in female lower reproductive tract and the biofilm formation of Candida albicans in vitro.METHODS Streptococcus agalactiae,Enterococcus faecalis and Candida albicans were cultured in vitro.The minimum inhibitory concentration(MIC)of Sophoraflavescens alkaloids against the above 3 bacteria was detected respectively by AGAR plate dilution method.Crystal violet staining and confocal microscopic imaging were used to detect the effect of Sophora flavescens alkaloids on the biofilm formation of Candida albicans.Scanning electron microscopy imaging was used to observe the effects of Sophora flavescens alkaloids on the formation of biofilm and the morphology of colony.RESULTS The MIC values of Sophora flavescens alkaloids against Streptococcus agalactiae,Enterococcus faecalis and Candida albicans were 16,32 and 32 mg·mL-1,respectively.Sophora flavescens alkaloids had a significant inhibitory effect on the biofilm of Candida albicans at the concentration of 1 mg·mL-1(P<0.05),and the inhibitory degree was concentration-dependent,indicating the higher the concentration,the more obvious the inhibitory effect on the biofilm.Meanwhile,it was also observed by the electron microscope that with the increase of Sophora flavescens alkaloids concentration,not only the formation of Candida albicans biofilm was inhibited,but also the formation of hypha was suppressed,resulting in shorter hypha in the colony and loose interhyphal connections.CONCLUSION Sophora flavescens alkaloids could inhibit the growth of Streptococcus agalactiae,Enterococcus faecalis and Candida albicans to varying degrees,and could significantly inhibit the biofilm formation of Candida albicans and suppress the yeast-hypha conversion,which have important clinical significance in treating vaginitis and reducing recurrence.