AUTHOR=De Carolis Elena , Marchionni Federica , La Rosa Marilisa , Meis Jacques F. , Chowdhary Anuradha , Posteraro Brunella , Sanguinetti Maurizio 

TITLE=Are We Ready for Nosocomial Candida auris Infections? Rapid Identification and Antifungal Resistance Detection Using MALDI-TOF Mass Spectrometry May Be the Answer

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.645049

DOI=10.3389/fcimb.2021.645049

ISSN=2235-2988

ABSTRACT=<p>The occurrence of multidrug-resistant <italic>Candida auris</italic> isolates and the increased mortality associated with invasive infections or outbreaks due to this <italic>Candida</italic> species have been reported in many healthcare settings. Therefore, accurate and rapid identification at the species level of clinical <italic>C. auris</italic> isolates as well as their timely differentiation as susceptible or resistant to antifungal drugs is mandatory. Aims of the present study were to implement the MALDI-TOF mass spectrometry (MS) Bruker Daltonics Biotyper<sup>®</sup> database with <italic>C. auris</italic> spectrum profiles and to develop a fast and reproducible MS assay for detecting anidulafungin (AFG) resistance in <italic>C. auris</italic> isolates. After creation of main <italic>C. auris</italic> spectra, a score-oriented dendrogram was generated from hierarchical cluster analysis, including spectra of isolates from <italic>C. auris</italic> and other <italic>Candida</italic> (<italic>C. glabrata</italic>, <italic>C. guilliermondii</italic>, <italic>C. haemulonii</italic>, <italic>C. lusitaniae</italic>, and <italic>C. parapsilosis</italic>) or non-<italic>Candida</italic> (<italic>Rhodotorula glutinis</italic>) species. Cluster analysis allowed to group and classify the isolates according to their species designation. Then, a three-hour incubation antifungal susceptibility testing (AFST) assay was developed. Spectra obtained at null, intermediate, or maximum AFG concentrations were used to create composite correlation index matrices for eighteen <italic>C. auris</italic> isolates included in the study. All six resistant <italic>C. auris</italic> isolates were detected as resistant whereas 11 of 12 susceptible <italic>C. auris</italic> isolates were detected as susceptible by the MS-AFST assay. In conclusion, our MS-based assay offers the possibility of rapidly diagnosing and appropriately treating patients with <italic>C. auris</italic> infection.</p>