多肽bCAT通过下调白念珠菌HWP1基因表达抑制生物被膜的形成机制

发布时间：2018-11-23 13:13

【摘要】：目的明确多肽bCAT抑制白念珠菌生物被膜形成能力,并探索其与黏附基因HWP1表达的关系。方法标准菌株白念珠菌ATCC10231和临床菌株作为研究对象,XTT法检测其生物被膜形成能力,bCAT抗浮游白念珠菌的MIC值以CLSI-M27-A3方法确定,XTT法及菌落计数检测bCAT抑制生物被膜形成作用,并计算代谢活性确定抑制50%生物被膜形成的MIC(BIC_(50)),bCAT减少白念珠菌的黏附作用经倒置显微镜下观察及菌落计数法检测,并采用RT-PCR通过2~(-ΔΔCt)法计算HWP1的表达量。统计方法为单因素方差分析,组内比较采用Dunnett T3检验。结果标准菌株及临床菌株均有较强生物被膜形成能力。bCAT抗浮游状态的白念珠菌MIC值为40~80μmol/L,BIC_(50)为80~160μmol/L;并且bCAT能减少白念珠菌的黏附作用,空白对照组菌落计数为(27 822.22±2 472.74)cfu,bCAT浓度为160、80、40、20、10μmol/L时的菌落个数分别为(5 355.55±1 264.03)cfu、(11 377.78±2 232.58)cfu、(17 488.89±1 136.27)cfu、(22 377.78±3 521.99)cfu、(26 044.44±1 329.57)cfu。组间差异具有统计学意义(F=147.018,P=0.001),组内比较发现160、80、40μmol/L处理组与不含bCAT时差异具有统计学意义(P0.05)。RT-PCR发现160μmol/L处理组HWP1相对表达量为空白对照组的12.24%。结论 bCAT能有效抑制白念珠菌生物被膜形成,其机制可能与降低HWP1基因的表达从而减少白念珠菌的黏附有关。具有一定的临床前景。
[Abstract]:Objective to investigate the inhibitory effect of polypeptide bCAT on biofilm formation of Candida albicans and its relationship with the expression of adhesion gene HWP1. Methods the biofilm forming ability of Candida albicans ATCC10231 and clinical strains was detected by XTT method. The MIC value of bCAT against Candida albicans was determined by CLSI-M27-A3 method. XTT and colony count were used to detect the inhibitory effect of bCAT on biofilm formation, and the metabolic activity was calculated to determine the inhibitory effect of MIC (BIC_ (50),) on biofilm formation by 50% biofilm. The effect of bCAT on the adhesion of Candida albicans was observed under inverted microscope and detected by colony counting method. The expression of HWP1 was calculated by RT-PCR through 2- 螖 Ct method. The statistical method was single factor ANOVA and Dunnett T3 test was used for intra-group comparison. Results both the standard strain and clinical strain had strong biofilm forming ability. The MIC of Candida albicans with bCAT resistance to plankton was 400.80 渭 mol/L,BIC_ (50), 80,160 渭 mol/L;. BCAT could reduce the adhesion of Candida albicans. When the colony count of blank control group was (27 822.22 卤2 472.74) cfu,bCAT, the number of colony was (5 355.55 卤1 264.03) cfu, (11 377.78 卤2 232.58) cfu, at the concentration of 160 mol/L. (17 488.89 卤1 136.27) cfu, (22 377.78 卤3 521.99) cfu, (26 044.44 卤1 329.57) cfu. The difference between groups was statistically significant (FF147.018P0. 001). There was significant difference between 160 渭 mol/L and 40 渭 mol/L groups (P0.05). The relative expression of HWP1 in 160 渭 mol/L treated group was 12.24% of that in the blank control group (P0.05). Conclusion bCAT can effectively inhibit the formation of biofilm in Candida albicans, and its mechanism may be related to the reduction of the expression of HWP1 gene and the decrease of adhesion of Candida albicans. It has certain clinical prospect.
【作者单位】：重庆医科大学附属第一医院重症医学科;重庆医科大学附属第一医院肝胆外科;
【基金】：重庆市卫计委重点项目(2016ZDXM001)
【分类号】：R379.4

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