Biological consequences of petite mutations in Candida glabrata
Biological consequences of petite mutations in Candida glabrata
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DOI：
10.1093/jac/dki200
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发表时间：
2005-08-01
影响因子：
5.2
通讯作者：
Bouchara, JP
中科院分区：
文献类型：
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作者：
Brun, S;Dalle, F;Bouchara, JP
目的：为了确定光滑念珠菌的呼吸缺陷突变株的致病性，该突变株对唑类药物的敏感性降低，容易在体外通过暴露于这些药物或溴化乙锭诱导，并且可以在接受氟康唑的患者体内选择。比较了glabrata与氟康唑或溴化乙锭诱导的petite突变体细胞壁的碳水化合物和蛋白质组成、表面物理性质以及它们在小鼠体内的粘附能力和毒性。使用几种荧光凝集素对细胞壁碳水化合物的流式细胞术分析显示，与其亲本分离物相比，突变细胞与伴刀豆球蛋白A的结合增加，表明娇小突变体中细胞表面的葡萄糖-甘露糖残基的可用性更高或量增加。同样，在芽生孢子的蛋白提取物中，通过SDS-PAGE显示亲本和突变体分离物之间的一些定量差异。关于表面的物理性质，没有显着差异，被认为是在电泳迁移率确定的微电泳，但两相分配方法揭示了较低的细胞表面疏水性娇小的突变体。此外，突变体细胞表现出显着的CgEPA 1的过度表达所揭示的实时逆转录-PCR，但粘附能力的Caco-2细胞，人肠上皮细胞系，没有显着差异。最后，在协议与他们的缓慢增长，娇小的突变体毒性小于亲株在小鼠模型的全身infection.Conclusion：这在小鼠中的低毒力表明娇小的突变体可以忽略临床上，虽然他们可能会出现在氟康唑治疗。
Objectives: To define the pathogenicity of respiration-deficient mutants of Candida glabrata, which present a reduced susceptibility to azoles, that are easily induced in vitro by exposure to these drugs or to ethidium bromide and that may be selected in vivo in patients receiving fluconazole.Methods: Two wild-type isolates of C. glabrata were compared with their respective fluconazole- or ethidium bromide-induced petite mutants, regarding the carbohydrate and protein composition of the cellwall, as well as their surface physical properties, and also their adherence abilities and virulence in mice.Results: Flow cytometric analysis of cell wall carbohydrates using several fluorescent lectins showed an increased binding of mutant cells to concanavalin A compared with their parent isolates, suggesting a greater availability or an increased amount of glucose-mannose residues at the cell surface in petite mutants. Likewise, some quantitative differences between parent and mutant isolates were shown by SDS-PAGE in protein extracts from blastoconidia. Regarding the surface physical properties, no significant differences were seen in the electrophoretic mobility determined by microelectrophoresis, but the two-phase partitioning method revealed a lower cell surface hydrophobicity for petite mutants. Moreover, mutant cells exhibited significant overexpression of CgEPA1 as revealed by real-time reverse transcription-PCR, but the adherence capacities to Caco-2 cells, a human enterocyte line, were not significantly different. Finally, in agreement with their slower growth, petite mutants were less virulent than parent isolates in a murine model of systemic infection.Conclusion: This low virulence in mice suggests that petite mutants could be disregarded clinically although they may arise during fluconazole therapy.