ABSTRACT
The genus
Malassezia
comprises commensal yeasts on human skin. These yeasts are involved in superficial infections but are also isolated in deeper infections, such as fungemia, particularly in certain at-risk patients, such as neonates or patients with parenteral nutrition catheters. Very little is known about
Malassezia
epidemiology and virulence. This is due mainly to the difficulty of distinguishing species. Currently, species identification is based on morphological and biochemical characteristics. Only molecular biology techniques identify species with certainty, but they are time-consuming and expensive. The aim of this study was to develop and evaluate a matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) database for identifying
Malassezia
species by mass spectrometry. Eighty-five
Malassezia
isolates from patients in three French university hospitals were investigated. Each strain was identified by internal transcribed spacer sequencing. Forty-five strains of the six species
Malassezia
furfur
,
M. sympodialis
,
M. slooffiae
,
M. globosa
,
M. restricta
, and
M. pachydermatis
allowed the creation of a MALDI-TOF database. Forty other strains were used to test this database. All strains were identified by our
Malassezia
database with log scores of >2.0, according to the manufacturer's criteria. Repeatability and reproducibility tests showed a coefficient of variation of the log score values of <10%. In conclusion, our new
Malassezia
database allows easy, fast, and reliable identification of
Malassezia
species. Implementation of this database will contribute to a better, more rapid identification of
Malassezia
species and will be helpful in gaining a better understanding of their epidemiology.
Improved mass accuracy in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of peptides
