氨基丁酸联合卡泊芬净的体外抗白色假丝酵母菌协同作用研究

目的探讨氨基丁酸联合卡泊芬净体外抗白色假丝酵母菌的协同作用。方法采用CLSI公布的M27-A方案微量棋盘液基稀释法测定氨基丁酸单用以及联合卡泊芬净对白色假丝酵母菌标准株SC5314的MIC80值和FICI值。采用抗真菌试管敏感性实验,考察给药24h后,卡泊芬净单用以及氨基丁酸联合卡泊芬净对白色假丝酵母菌SC5314生长的影响。采用生长曲线实验,测定氨基丁酸联合卡泊芬净抗白色假丝酵母菌SC5314的生长曲线。结果氨基丁酸单用对白色假丝酵母菌SC5314的MIC80>20μmol·L-1,说明氨基丁酸单用对SC5314没有抑菌作用;但1.25μmol·L-1氨基丁酸与卡泊芬净合用的FICI<0.5,说明氨基丁酸与卡泊芬净合用表现出协同关系。另外,在抗真菌试管敏感性实验中,1.25μmol·L-1的氨基丁酸联合0.012 5μg·mL-1的卡泊芬净与0.012 5μg·mL-1的卡泊芬净单用组相比,可以直观地观察到试管内浑浊程度明显减弱,SC5314的生长受到抑制。在生长曲线实验中,1.25μmol·L-1氨基丁酸联合0.012 5μg·mL-1卡泊芬净的生长曲线显著低于同浓度下两药单用的生长曲线(P<0.05)。结论氨基丁酸本身对白色假丝酵母菌标准株SC5314没有抑菌作用,但氨基丁酸能显著增强卡泊芬净对白色假丝酵母菌SC5314的杀菌作用。

Synergetic antifungal effect of aminobutyric acid with caspofungin against Candida albicans

Objective To investigate the influence of aminobutyric acid （GABA） on the antifungal effect of caspofungin against Can-dida albicans .Methods Standard stains of Candida albicans SC5314 were used in this study .The minimal inhibitory concentra-tion for 80% （MIC80 ） and the fractional inhibitory concentration index （FICI） were determined by broth microdilution antifungal susceptibility test （published by CLSI） .The antifungal susceptibility assay was used in this study ,at about 24 h post-dose .The group of GABA with caspofungin comparing with the group of caspofungin only was calculated .The growth curves of GABA on-ly ,caspofungin only and GABA with caspofungin against SC5314 were performed for indicating whether GABA with caspofungin has the synergetic antifungal effect against Candida albicans .Results The MIC80 of GABA against SC5314 was 〉 20 μmol ？ L - 1 , which showed that the antifungal effect of GABA only was weak ;however ,the FICI values of SC5314 for combination of GABA with caspofungin was less than 0 .5 ,indicating the presence of synergism .And then ,we clearly observed that the groups of GA-BA （1 .25 μmol ？ L - 1 ） combination of caspofungin （0 .012 5 μg ？ mL - 1 ） showed an adverse effect on the growth of SC5314 compa-ring with the group of caspofungin only .And the growth curve of GABA （1 .25 μmol ？ L - 1 ） with caspofungin （0 .012 5 μg ？ mL - 1 ） against SC5314 was clearly reduced （P〈 0 .05） comparing with the groups of GABA only and caspofungin only .Conclusion The antifungal effect of GABA against Candida albicans SC5314 was weak ,while GABA and caspofungin possess synergetic effect against Candida albicans SC5314 .