Performance of the VITEK® MS system for the identification of filamentous fungi in a microbiological laboratory in Chile

Filamentous fungi are an emergent cause of severe infections in immunocompromised patients. Timely and accurate identification is crucial to initiate appropriate therapy. Traditional identification methods are time-consuming, labor-intensive, and operator-dependent. Matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry is a rapid and easy-to-perform identification method. The effectiveness of a commercial MALDI-TOF MS platform to identify filamentous fungi in a clinical laboratory was evaluated. The study included 67 fungal isolates from 35 species/species complexes, which were identified and confirmed in mycology reference laboratories; 32 derived from clinical samples, 34 from strain collections and one was an ATCC strain. The study used the VITEK® MS system (v3.2.0 database), after sample extraction by VITEK® MS Mould Kit. Results were classified as “correct species”, “correct species complex”, “correct genus”and “no identification”. VITEK® MS correctly identified 91.0% of isolates (58.2% to species, 29.9% to species complex, and 1.5% to genus level only). In 82%, the result matched the species/species complex identified by reference methods. No misidentifications were observed. The kit was rapid and easy to use. In conclusion, the VITEK® MS system showed a high capability to accurately identify filamentous fungi in a clinical laboratory.

Subjects

chile

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fungi

;

humans

;

laboratories

;

mycoses

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spectrometry, mass, matrix-assisted laser desorption-ionization

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trehalose

;

alternaria alternata

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article

;

aspergillus

;

aspergillus brasiliensis

;

aspergillus calidoustus

;

aspergillus flavus

;

aspergillus fumigatus

;

aspergillus nidulans

;

aspergillus niger

;

aspergillus sydowii

;

aspergillus terreus

;

aspergillus tritici

;

aspergillus versicolor

;

chile

;

coccidioides

;

coccidioides posadasii

;

controlled study

;

curvularia spicifera

;

epidermophyton floccosum

;

escherichia coli

;

filamentous fungus

;

fungus culture

;

fungus identification

;

fusarium proliferatum

;

fusarium solani

;

lichtheimia corymbifera

;

matrix assisted laser desorption ionization time of flight mass spectrometry

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microbiology

;

mucor

;

mucor velutinosus

;

nonhuman

;

penicillium

;

penicillium brevicompactum

;

penicillium canescens

;

penicillium chrysogenum

;

penicillium expansum

;

penicillium roqueforti

;

polymerase chain reaction

;

purpureocillium lilacinum

;

rhizopus delemar

;

rhizopus microsporus

;

rhizopus oryzae

;

sarocladium

;

sarocladium kiliense

;

sarocladium strictum

;

scedosporium boydii

;

sequence analysis

;

species identification

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sporothrix

;

sporothrix globosa

;

trichophyton rubrum

;

trichophyton tonsurans

;

chile

;

classification

;

diagnosis

;

fungus

;

human

;

isolation and purification

;

laboratory

;

matrix-assisted laser desorption-ionization mass spectrometry

;

microbiology

;

procedures