TY - JOUR

T1 - Identification of Dermatophyte and mold species by MALDI-TOF Mass Spectrometry

AU - Reich, Marco

AU - Stark, Maik

AU - Huesgen, G.

AU - Bosshard, Philipp P.

AU - Borgmann, Stefan

N1 - Funding Information: The authors would like to thank Dagmar Beier for reading of the manuscript. Work in the authors’ labs was supported by grants from the priority programmes SFB554 (H.F.), SFB567 (R.G.), and SPP1127 (H.F.) of the Deutsche Forschungsgemeinschaft.

PY - 2009/9/1

Y1 - 2009/9/1

N2 - Routine procedures for dermatophyte and mold identification rely on anexamination of strain characteristics and microscopic morphology.Conventional methods used to identify dermatophytes and molds are oftentime-consuming and may be inconclusive because of atypical microscopic orcolony morphology. The present study evaluates a promising alternative basedon the analysis of clinical fungal isolates by MALDI-TOF mass spectrometry.A total of 63 isolates belonging to 27 species of dermatophytes and molds wereanalyzed. The isolates were obtained from reference samples(„Ringversuchsproben“, INSTAND e.V., n= 17) as well as from reliableidentified clinical isolates from a variety of specimens including skin, nailscrapings and hair fragments. The clinical isolates were obtained from theUniversity Hospital of Zurich (Department of Dermatology, n= 30) and fromthe Synlab Laboratory Leinfelden (n=16). Because many fungi attached verystrong to agar, sample harvesting without agar contamination was not possible.Therefore, the isolates were additionally inoculated in liquid culture media.Almost 93% (59 of 63) of the MALDI-TOF identification results matched tothose of conventional methods respectively to the identity of the referencesamples. Four mismatches were obtained from clinical isolates. Trichophytonmentagropytes var. Interdigitale was identified incorrectly as Trichophytontonsurans (n= 4). However these mismatches arise from database discrepancyand could be eliminated by further development of the database.In Summary,MALDI- TOF analyses of common dermatophytes and molds resulted inreliable species identification. Furthermore, this procedure allowed very rapididentification results. The isolates could be identified already after a growthtime of 4-14 days, when inoculated in liquid culture media.

AB - Routine procedures for dermatophyte and mold identification rely on anexamination of strain characteristics and microscopic morphology.Conventional methods used to identify dermatophytes and molds are oftentime-consuming and may be inconclusive because of atypical microscopic orcolony morphology. The present study evaluates a promising alternative basedon the analysis of clinical fungal isolates by MALDI-TOF mass spectrometry.A total of 63 isolates belonging to 27 species of dermatophytes and molds wereanalyzed. The isolates were obtained from reference samples(„Ringversuchsproben“, INSTAND e.V., n= 17) as well as from reliableidentified clinical isolates from a variety of specimens including skin, nailscrapings and hair fragments. The clinical isolates were obtained from theUniversity Hospital of Zurich (Department of Dermatology, n= 30) and fromthe Synlab Laboratory Leinfelden (n=16). Because many fungi attached verystrong to agar, sample harvesting without agar contamination was not possible.Therefore, the isolates were additionally inoculated in liquid culture media.Almost 93% (59 of 63) of the MALDI-TOF identification results matched tothose of conventional methods respectively to the identity of the referencesamples. Four mismatches were obtained from clinical isolates. Trichophytonmentagropytes var. Interdigitale was identified incorrectly as Trichophytontonsurans (n= 4). However these mismatches arise from database discrepancyand could be eliminated by further development of the database.In Summary,MALDI- TOF analyses of common dermatophytes and molds resulted inreliable species identification. Furthermore, this procedure allowed very rapididentification results. The isolates could be identified already after a growthtime of 4-14 days, when inoculated in liquid culture media.

KW - Chemistry

KW - Biology

KW - Animals

KW - Bacterial Physiological Phenomena

KW - Cell Physiological Phenomena

KW - Cells/microbiology

KW - Insecta/cytology

KW - Symbiosis

UR - http://www.journals.elsevier.com/international-journal-of-medical-microbiology/special-issues/

UR - http://www.scopus.com/inward/record.url?scp=56949106496&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/44f19529-a171-35ec-a82b-a8def771c926/

U2 - 10.1016/j.ijmm.2009.08.001

DO - 10.1016/j.ijmm.2009.08.001

M3 - Conference abstract in journal

C2 - 18640072

VL - 299

SP - 13

JO - International Journal of Medical Microbiology

JF - International Journal of Medical Microbiology

SN - 1438-4221

IS - Supplement 1

M1 - EKP09

ER -