ITS rDNA Gene Analysis Versus MALDI-TOF MS For Identification of <i>Neoscytalidium dimidiatum</i> Isolated from Onychomycosis and Dermatomycosis Cases in Medellin (Colombia)

• Main Authors: Sindy V. Flórez-Muñoz, Juan C. Gómez-Velásquez, Natalia Loaiza-Díaz, Célia Soares, Carla Santos, Nelson Lima, Ana C. Mesa-Arango
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Microorganisms
• Subjects: Neoscytalidium dimidiatum; Botryosphaeriaceae; ITS rDNA region; MALDI-TOF MS; onychomycosis; dermatomycosis
• Online Access: https://www.mdpi.com/2076-2607/7/9/306

Within the <i>Neoscytalidium</i> genus, <i>N. dimidiatum</i>, <i>N. oculus</i>, <i>N. orchidacearum,</i> and <i>N. novaehollandiae</i> have been recognized. Although these species are frequently found in soil, <i>N. dimidiatum</i> has been identified as an etiologic agent of onychomycosis or dermatomycosis, and <i>N. oculus</i> has been identified as an etiologic agent of an ocular lesion. All these species can be cultured <i>in vitro</i>, but their morphological identification by macroscopic and microscopic traits is difficult and imprecise due to their similarity. In this study, 34 isolates of <i>Neoscytalidium</i> spp. from 32 onychomycosis and two dermatomycosis cases in Medellin (Colombia) were identified at the species level using sequencing of the ITS1+5.8S+ITS2 nuclear rDNA region and MALDI-TOF mass spectrometry (MS). <i>Neoscytalidium dimidiatum</i> strain MUM 17.21 was used to construct the reference spectrum in the in-house library to identify the clinical isolates by MALDI-TOF MS. Additionally, <i>N. dimidiatum</i> PPC-216 and PLAB-055 strains were used to validate the in-house constructed reference spectra. Although four groups were observed in the dendrogram obtained from the proteins of each isolate profile, MALDI-TOF MS and sequencing results are in accordance, since all isolates were identified as <i>N. dimidiatum</i>.