Vahedi-Shahandashti Roya, Moroder Eleonora, Lass-Flörl Cornelia
Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.
Antimicrob Agents Chemother. 2025 Aug 6;69(8):e0024125. doi: 10.1128/aac.00241-25. Epub 2025 Jul 1.
Antifungal susceptibility testing (AFST) is essential for clinical decisions to effectively select optimal therapy against fungal infections. Reference standard broth microdilution methods provide accurate results; however, they are more challenging and time-consuming compared to conventional susceptibility testing methods such as gradient diffusion strips (Etest). This study assessed the Clinical and Laboratory Standards Institute (CLSI) yeast protocol and Etest for determining the echinocandin susceptibility profile (anidulafungin, caspofungin, micafungin, and rezafungin) in isolates ( = 60). A full agreement (100%) was observed between Etest and CLSI for caspofungin, micafungin, and rezafungin, but surprisingly, the agreement for anidulafungin was only 43.3%. Notably, 56.6% of isolates were anidulafungin resistant by Etest, whereas CLSI detected no resistance. Analysis of 1 gene hotspots (HS1 and HS2) revealed no mutations, proving that anidulafungin susceptibility results are method-dependent rather than a consequence of actual resistance. Our findings suggest that Etest may overestimate anidulafungin resistance in , which can lead to false resistance categorization. The low agreement between the two methods, Etest and CLSI, highlights the need to address these issues through improved quality control of the anidulafungin Etest or methodological adjustments. Given that anidulafungin is considered the leading drug in AFST for , caution is recommended when interpreting Etest results without confirmation via broth microdilution. Since these discrepancies in categorization occur for a specific species and a particular antifungal, anidulafungin, within the echinocandin class, rather than for all agents in that class (with anidulafungin also serving as the reference agent in AFST), this may suggest that, in the case of , either an alternative method should be used for anidulafungin susceptibility testing, or other echinocandins should be considered as reference agents in clinical settings.
抗真菌药敏试验(AFST)对于临床决策至关重要,有助于有效选择针对真菌感染的最佳治疗方案。参考标准肉汤微量稀释法可提供准确结果;然而,与传统药敏试验方法(如梯度扩散条带法(Etest))相比,该方法更具挑战性且耗时更长。本研究评估了临床和实验室标准协会(CLSI)针对酵母菌的方案以及Etest在测定60株分离株中棘白菌素敏感性谱(阿尼芬净、卡泊芬净、米卡芬净和瑞扎芬净)方面的情况。对于卡泊芬净、米卡芬净和瑞扎芬净,Etest与CLSI之间观察到完全一致(100%),但令人惊讶的是,阿尼芬净的一致性仅为43.3%。值得注意的是,通过Etest检测,5... 此处原文似乎不完整,翻译暂时到此。通过Etest检测,56.6%的分离株对阿尼芬净耐药,而CLSI未检测到耐药情况。对1个基因热点区域(HS1和HS2)的分析未发现突变,这证明阿尼芬净的药敏结果取决于方法,而非实际耐药的结果。我们的研究结果表明,Etest可能高估了分离株中阿尼芬净的耐药性,这可能导致错误的耐药分类。Etest和CLSI这两种方法之间的低一致性凸显了通过改进阿尼芬净Etest的质量控制或进行方法调整来解决这些问题的必要性。鉴于阿尼芬净被认为是针对分离株的AFST中的主要药物,在未经肉汤微量稀释法确认的情况下解释Etest结果时建议谨慎。由于分类差异发生在棘白菌素类中的特定物种和特定抗真菌药物阿尼芬净上,而不是该类中的所有药物(阿尼芬净在AFST中也用作参考药物),这可能表明,对于分离株,要么应使用替代方法进行阿尼芬净药敏试验,要么在临床环境中应考虑将其他棘白菌素作为参考药物。