The antifungal echinocandin caspofungin acetate kills growing cells of Aspergillus fumigatus in vitro
The antifungal echinocandin caspofungin acetate kills growing cells of Aspergillus fumigatus in vitro
复制标题
DOI：
10.1128/aac.46.9.3001-3012.2002
复制
发表时间：
2002-09-01
影响因子：
4.9
通讯作者：
Douglas, CM
中科院分区：
文献类型：
--
作者：
Bowman, JC;Hicks, PS;Douglas, CM
醋酸卡泊芬净是一种抗真菌抗生素，可抑制1，3-β-D-葡聚糖的合成，1，3-β-D-葡聚糖是真菌细胞壁的重要成分。虽然卡泊芬净导致酵母菌和双相真菌（如白色念珠菌）的细胞死亡，但其对烟曲霉的影响尚不清楚。我们使用荧光染料5，（6）-羧基荧光素二乙酸酯（CFDA）和双-（1，3-二丁基巴比妥酸）三甲氧羰基（DiBAC），分别染色活细胞和死细胞，以进一步表征卡泊芬净的抗真菌活性。为了比较，还评价了作用模式为抑真菌（氟康唑、伊曲康唑）或杀真菌（阿替霉素B）的化合物。首先用C.建立了卡泊芬净诱导的活力丧失、CFDA染色减少和DiBAC染色增加之间的相关性。白色念珠菌。对于.烟曲霉，卡泊芬净引起类似的染料染色的变化，这是定量的荧光分析染色菌丝生长在培养基中，促进分散生长。产生这些变化所需的卡泊芬净的最低浓度也降低了指示染料Alcohol Blue的生长依赖性还原水平。我们观察到卡泊芬净作为细胞位置的函数的差异效应：88%的顶端细胞和61%的亚顶端分支细胞未能用活性染料CFDA染色，但只有24%的亚顶端细胞未染色。从DiBAC染色的卡泊芬净处理的培养物中观察到了补充结果。延长A.烟曲霉菌与单剂量卡泊芬净作用相同比例的顶端和亚顶端分支细胞长达72小时。染色图谱表明，细胞处于新细胞壁合成的活性中心。烟曲霉菌丝在暴露于卡泊芬净时被杀死。
Caspofungin acetate is an antifungal antibiotic that inhibits synthesis of 1,3-beta-D-glucan, an essential component of the fungal cell wall. While caspofungin causes cell death in yeasts and dimorphic fungi such as Candida albicans, its effect on Aspergillus fumigatus is less well understood. We used the fluorescent dyes 5,(6)-carboxyfluorescein diacetate (CFDA) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC), which stain live and dead cells, respectively, to further characterize the antifungal activity of caspofungin. For comparison, compounds whose mode of action was either fungistatic (fluconazole, itraconazole) or fungicidal (amphotericin B) were also evaluated. A correlation between caspofungin-induced loss of viability, decreased CFDA staining, and increased DiBAC staining was established first with C. albicans. For A. fumigatus, caspofungin caused similar dye-staining changes, which were quantified by fluorimetric analysis of stained hyphae grown in a medium that promoted dispersed growth. The minimum concentration of caspofungin required to produce these changes also decreased the level of growth-dependent reduction of the indicator dye Alamar Blue. We observed a differential effect of caspofungin as a function of cell position: 88% of apical cells and 61% of subapical branching cells failed to stain with the viable dye CFDA, but only 24% of subapical cells were unstained. Complementary results were seen with germlings from DiBAC-stained, caspofungin-treated cultures. Extended incubation of A. fumgatus with a single dose of caspofungin affected the same proportion of apical and subapical branching cells for up to 72 h. The dye-staining patterns illustrate that the cells at the active centers for new cell wall synthesis within A. fumigatus hyphae are killed when they are exposed to caspofungin.