Asadzadeh Mohammad, Ahmad Suhail, Meis Jacques F, Parker Josie E, Alfouzan Wadha
Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya 46300, Kuwait.
Department of Medical Microbiology, Radboud University Medical Center, 6525 Nijmegen, The Netherlands.
J Fungi (Basel). 2025 Jul 30;11(8):570. doi: 10.3390/jof11080570.
Invasive infections with rare yeasts are increasing worldwide and are associated with higher mortality rates due to their resistance to antifungal drugs. Accurate antifungal susceptibility testing (AFST) is crucial for proper management of rare yeast infections. We performed AFST of 74 isolates by Etest, EUCAST-based MICRONAUT-AM assay (MCN-AM) and reference Clinical and Laboratory Standards Institute broth microdilution method (CLSI). Essential agreement (EA, ±1 two-fold dilution), categorical agreement (CA), major errors (MEs) and very-major errors (VmEs) were determined using epidemiological cut-off values of ≤1.0 µg/mL, ≤0.03 µg/mL, ≤0.5 µg/mL and ≤1 µg/mL, defining wild-type isolates for fluconazole, voriconazole, micafungin and amphotericin B (AMB), respectively. Results for AMB susceptibility were correlated with mutations and total-cell sterols. CA of ≥97% was recorded between any two methods while EA varied between 72 and 82%, 87 and 92%, and 49 and 76% for fluconazole, voriconazole and micafungin, respectively. For AMB, CAs between CLSI and Etest; CLSI and MCN-AM; MCN-AM and Etest were 95% (4 ME, 0 VmE), 96% (3 ME, 0 VmE) and 99%, respectively, while EA varied from 32% to 69%. Non-synonymous mutations and no ergosterol were found in seven of eight isolates of non-wild types for AMB by Etest. Our data show that Etest, CLSI and MCN-AM methods are suitable for AFST of for fluconazole, voriconazole and micafungin. Excellent CAs for AMB between Etest and MCN-AM with concordant sterol profiles but not with CLSI suggest that Etest is also an excellent alternative for the detection of isolates with reduced susceptibility to AMB.
全球范围内，由罕见酵母菌引起的侵袭性感染正在增加，且由于其对抗真菌药物具有耐药性，导致死亡率更高。准确的抗真菌药敏试验（AFST）对于妥善管理罕见酵母菌感染至关重要。我们采用Etest法、基于欧洲抗菌药物敏感性试验委员会（EUCAST）的MICRONAUT-AM检测法（MCN-AM）以及参考的美国临床和实验室标准协会肉汤微量稀释法（CLSI），对74株分离株进行了AFST。使用氟康唑、伏立康唑、米卡芬净和两性霉素B（AMB）的流行病学截断值（分别为≤1.0 µg/mL、≤0.03 µg/mL、≤0.5 µg/mL和≤1 µg/mL）来确定基本一致性（EA，±1个两倍稀释度）、分类一致性（CA）、主要错误（ME）和非常主要错误（VmE），以定义野生型分离株。AMB药敏试验结果与突变和总细胞甾醇相关。任意两种方法之间的CA均≥97%，而氟康唑、伏立康唑和米卡芬净的EA分别在72%至82%、87%至92%和49%至76%之间变化。对于AMB，CLSI与Etest之间、CLSI与MCN-AM之间、MCN-AM与Etest之间的CA分别为95%（4个ME，0个VmE）、96%（3个ME，0个VmE）和99%，而EA在32%至69%之间变化。通过Etest法在8株非野生型AMB分离株中的7株中发现了非同义突变且无麦角甾醇。我们的数据表明，Etest法、CLSI法和MCN-AM法适用于氟康唑、伏立康唑和米卡芬净的AFST。Etest与MCN-AM之间对于AMB具有出色的CA且甾醇谱一致，但与CLSI不一致，这表明Etest也是检测对AMB敏感性降低的分离株的出色替代方法。
