AUTHOR=Takei Satomi , Teramoto Kanae , Fujimura Junya , Fujiwara Megumi , Suzuki Mai , Fukui Yukiko , Sekiguchi Yuji , Kawakami Takaaki , Chonan Masayoshi , Wakita Mitsuru , Horiuchi Yuki , Miida Takashi , Naito Toshio , Kirikae Teruo , Tada Tatsuya , Tabe Yoko 

TITLE=Isolation and identification of Wickerhamiella tropicalis from blood culture by MALDI-MS

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1361432

DOI=10.3389/fcimb.2024.1361432

ISSN=2235-2988

ABSTRACT=<p><italic>Wickerhamiella</italic> is a genus of budding yeast that is mainly isolated from environmental samples, and 40 species have been detected. The yeast isolated from human clinical samples usually only contain three species: <italic>W. infanticola</italic>, <italic>W. pararugosa</italic> and <italic>W. sorbophila</italic>. In this study, we isolated <italic>W. tropicalis</italic> from a blood sample of a six-year-old female with a history of B-cell precursor lymphoblastic leukemia in Japan in 2022. Though the strain was morphologically identified as <italic>Candida</italic> species by routine microbiological examinations, it was subsequently identified as <italic>W. tropicalis</italic> by sequencing the internal transcribed spacer (ITS) of ribosomal DNA (rDNA). The isolate had amino acid substitutions in ERG11 and FKS1 associated with azole and echinocandin resistance, respectively, in <italic>Candida</italic> species and showed intermediate-resistant to fluconazole and micafungin. The patient was successfully treated with micafungin. Furthermore, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) detected three novel peaks that are specific for <italic>W. tropicalis</italic>, indicating that MALDI-MS analysis is useful for rapid detection of <italic>Wickerhamiella</italic> species in routine microbiological examinations.</p>