Posteraro Brunella, Spanu Teresa, Fiori Barbara, De Maio Flavio, De Carolis Elena, Giaquinto Alessia, Prete Valentina, De Angelis Giulia, Torelli Riccardo, D'Inzeo Tiziana, Vella Antonietta, De Luca Alessio, Tumbarello Mario, Ricciardi Walter, Sanguinetti Maurizio
Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Rome, Italy.
Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
Antimicrob Agents Chemother. 2015 Jul;59(7):3944-55. doi: 10.1128/AAC.00285-15. Epub 2015 Apr 20.
Sensititre YeastOne (SYO) is an affordable alternative to the Clinical and Laboratory Standards Institute (CLSI) reference method for antifungal susceptibility testing. In this study, the MICs of yeast isolates from 1,214 bloodstream infection episodes, generated by SYO during hospital laboratory activity (January 2005 to December 2013), were reanalyzed using current CLSI clinical breakpoints/epidemiological cutoff values to assign susceptibility (or the wild-type [WT] phenotype) to systemic antifungal agents. Excluding Candida albicans (57.4% of all isolates [n = 1,250]), the most predominant species were Candida parapsilosis complex (20.9%), Candida tropicalis (8.2%), Candida glabrata (6.4%), Candida guilliermondii (1.6%), and Candida krusei (1.3%). Among the non-Candida species (1.9%), 7 were Cryptococcus neoformans and 17 were other species, mainly Rhodotorula species. Over 97% of Candida isolates were susceptible (WT phenotype) to amphotericin B and flucytosine. Rates of susceptibility (WT phenotype) to fluconazole, itraconazole, and voriconazole were 98.7% in C. albicans, 92.3% in the C. parapsilosis complex, 96.1% in C. tropicalis, 92.5% in C. glabrata, 100% in C. guilliermondii, and 100% (excluding fluconazole) in C. krusei. The fluconazole-resistant isolates consisted of 6 C. parapsilosis complex isolates, 3 C. glabrata isolates, 2 C. albicans isolates, 2 C. tropicalis isolates, and 1 Candida lusitaniae isolate. Of the non-Candida isolates, 2 C. neoformans isolates had the non-WT phenotype for susceptibility to fluconazole, whereas Rhodotorula isolates had elevated azole MICs. Overall, 99.7% to 99.8% of Candida isolates were susceptible (WT phenotype) to echinocandins, but 3 isolates were nonsusceptible (either intermediate or resistant) to caspofungin (C. albicans, C. guilliermondii, and C. krusei), anidulafungin (C. albicans and C. guilliermondii), and micafungin (C. albicans). However, when the intrinsically resistant non-Candida isolates were included, the rate of echinocandin nonsusceptibility reached 1.8%. In summary, the SYO method proved to be able to detect yeast species showing antifungal resistance or reduced susceptibility.
Sensititre YeastOne（SYO）是一种价格亲民的抗真菌药敏试验方法，可替代临床和实验室标准协会（CLSI）的参考方法。在本研究中，对2005年1月至2013年12月医院实验室活动期间SYO产生的1214例血流感染病例中的酵母分离株的最低抑菌浓度（MIC），使用当前CLSI临床断点/流行病学临界值重新进行分析，以确定系统性抗真菌药物的敏感性（或野生型[WT]表型）。排除白色念珠菌（占所有分离株的57.4%[n = 1250]）后，最主要的菌种是近平滑念珠菌复合体（20.9%）、热带念珠菌（8.2%）、光滑念珠菌（6.4%）、季也蒙念珠菌（1.6%）和克柔念珠菌（1.3%）。在非念珠菌属菌种（1.9%）中，7株为新生隐球菌，17株为其他菌种，主要是红酵母属菌种。超过97%的念珠菌分离株对两性霉素B和氟胞嘧啶敏感（WT表型）。白色念珠菌对氟康唑、伊曲康唑和伏立康唑的敏感率（WT表型）分别为98.7%、92.3%、96.1%、92.5%、100%和100%（氟康唑除外）。耐氟康唑的分离株包括6株近平滑念珠菌复合体分离株、3株光滑念珠菌分离株、2株白色念珠菌分离株、2株热带念珠菌分离株和1株葡萄牙念珠菌分离株。在非念珠菌分离株中，2株新生隐球菌分离株对氟康唑的敏感性为非WT表型，而红酵母属分离株的唑类MIC升高。总体而言，99.7%至99.8%的念珠菌分离株对棘白菌素敏感（WT表型），但有3株对卡泊芬净（白色念珠菌、季也蒙念珠菌和克柔念珠菌）、阿尼芬净（白色念珠菌和季也蒙念珠菌）和米卡芬净（白色念珠菌）不敏感（中介或耐药）。然而，当纳入固有耐药的非念珠菌分离株时，棘白菌素不敏感率达到1.8%。总之，SYO方法被证明能够检测出显示抗真菌耐药或敏感性降低的酵母菌种。
