In vitro antifungal drug susceptibilities of dermatophytes microconidia and arthroconidia
In vitro antifungal drug susceptibilities of dermatophytes microconidia and arthroconidia
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DOI：
10.1093/jac/dkn245
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发表时间：
2008-10-01
影响因子：
5.2
通讯作者：
Martinez-Rossi, Nilce M.
中科院分区：
文献类型：
--
作者：
Coelho, Luciene M.;Aquino-Ferreira, Roseli;Martinez-Rossi, Nilce M.
目的：节孢子虫是引起皮肤癣菌感染的主要原因。然而，体外抗真菌试验主要评估小分生孢子或菌丝的反应，并且皮肤真菌在体内通常产生节分生孢子，这是一种细胞结构，推测对抗真菌剂更具抗性。本研究的目的是比较红色毛癣菌、断毛癣菌和马毛癣菌的小分生孢子和节分生孢子对灰黄霉素、伊曲康唑、特比萘芬、氟康唑、两性霉素B和潮霉素B的体外敏感性。方法：在体外产生小分生孢子和节分生孢子，并通过评估CLSI M38-A肉汤微量稀释法评估其对每种药物的敏感性。结果：节分生孢子对氟康唑、灰黄霉素和伊曲康唑的耐药性高于小分生孢子。特比萘芬对所有菌株的小分生孢子和节分生孢子的MIC相同，阿替霉素B对所有菌株的小分生孢子和节分生孢子的MIC相同。equinum和T. tonsurans，但T.红色。最后，所有菌株对抗生素潮霉素B的小分生孢子的抗性水平为25至400 mg/L。结论：小分生孢子和节分生孢子之间的敏感性差异取决于药物和菌株，可能是治疗失败的原因之一。此外，这些菌株的小分生孢子对抗生素潮霉素B的抗性水平将允许在未来的基因功能研究中使用潮霉素抗性作为真菌转化程序中的显性标记。
Objectives: Arthroconidia have been considered as the primary cause of infection by dermatophytes. However, the in vitro antifungal testing evaluates the responses mainly of microconidia or hyphae, and dermatophytes in vivo often produce arthroconidia, a cellular structure presumably more resistant to antifungals. The aim of this study was to compare the in vitro susceptibility of microconidia and arthroconidia of Trichophyton rubrum, Trichophyton tonsurans and Trichophyton equinum to griseofulvin, itraconazole, terbinafine, fluconazole, amphotericin B and hygromycin B.Methods: Microconidia and arthroconidia were produced in vitro, and their susceptibility to each drug was evaluated by assessing the CLSI M38-A broth microdilution method.Results: Arthroconidia of all strains analysed appeared to be more resistant to fluconazole, griseofulvin and itraconazole than microconidia. The MIC of terbinafine was the same for microconidia and arthroconidia for all strains, and the MIC of amphotericin B for microconidia and arthroconidia was the same for isolates of T. equinum and T. tonsurans, but differed for T. rubrum. Finally, the level of resistance of microconidia for all strains towards the antibiotic hygromycin B was from 25 to 400 mg/L.Conclusions: The difference in the susceptibility between microconidia and arthroconidia depends on the drug and on the strain, and may be one of the causes of therapeutic failure. Also, the level of resistance to the antibiotic hygromycin B presented by microconidia of these isolates will allow the use of hygromycin resistance as a dominant marker in fungal transformation procedures in future studies of gene function.