Robert Marie Gladys, Romero Charlotte, Dard Céline, Garnaud Cécile, Cognet Odile, Girard Thomas, Rasamoelina Tahinamandranto, Cornet Muriel, Maubon Danièle
Laboratoire de Parasitologie et Mycologie, CHU Grenoble Alpes, Grenoble, France
Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France.
J Clin Microbiol. 2020 Apr 23;58(5). doi: 10.1128/JCM.01687-19.
MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP ( = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) ( = <0.001 and = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol.
基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）对致病性丝状真菌的鉴定常常因难以收获嵌入培养基中的菌丝以及冗长的提取方案而受到阻碍。ID真菌平板（IDFP）是一种新开发的培养方法，旨在解决此类难题并通过MALDI-TOF MS改进丝状真菌的鉴定。我们在IDFP、沙氏琼脂-氯霉素（SAB）和显色念珠菌琼脂（CAN2）上培养了64株菌株和11份临床样本。然后我们比较了这三种培养基在生长、收获难易程度、采集的材料量以及快速直接转移（DT）或长时间乙醇-乙腈（EA）提取方案后的MALDI-TOF鉴定分数。还比较了在SAB和IDFP上继代培养后十种霉菌的抗真菌药敏试验和微观形态。三种培养基的生长速率和形态方面相似。使用IDFP时，在92.4%的病例中，用于提取程序的真菌材料收获迅速且容易，而在SAB或CAN2上分别有65.2%和80.3%的病例中收获过程很繁琐。使用IDFP的两种提取方案中，得分高于1.7（定义为可接受鉴定）的比例相当（P = 0.256）。此外，在IDFP上进行DT后可接受鉴定的比例（93.9%）显著高于用SAB（69.7%）或CAN2（71.2%）进行EA提取后获得的比例（分别为P <0.001和P = 0.001）。IDFP和SAB之间的形态方面和抗真菌药敏试验相似。IDFP是一种有助于并改进丝状真菌鉴定的培养平板，允许使用快速提取方案通过MALDI-TOF-MS对霉菌进行准确的常规鉴定。
