Rapid and robust identification of clinical isolates of Talaromyces marneffei based on MALDI-TOF mass spectrometry or dimorphism in Galleria mellonella.
Med Mycol
; 57(8): 969-975, 2019 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-30649411
ABSTRACT
Talaromyces marneffei is a thermally dimorphic fungal pathogen that causes serious infections particularly in patients with human immunodeficiency virus (HIV). Although the mould form typically produces a characteristic red-diffusing pigment, and conidia from penicillate heads, several nonpathogenic Talaromyces/Penicillium species are morphologically and phenotypically similar. While those other species do not exhibit thermal dimorphism, conversion of T. marneffei to the distinctive fission yeast form in vitro is arduous and frequently incomplete. Here we show that T. marneffei can be rapidly and unambiguously discriminated from related nonpathogenic Talaromyces/Penicillium spp., either by matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry or conversion to fission yeast after introduction into Galleria mellonella. Conversion of T. marneffei conidia to the fission yeast form in G. mellonella larvae occurred as early as 24 h post inoculation at 37oC. Identification by MALDI-TOF was possible after supplementation of the commercial Bruker database with in-house mass spectral profiles created from either the yeast or mycelial phase of T. marneffei. In addition, we show that in-house generated mass spectral profiles could be successfully used to identify T. marneffei with a recently published on-line MALDI-TOF database, circumventing the need to create extensive in-house additional databases for rarely encountered fungal pathogens.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Técnicas Microbiológicas
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Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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Talaromyces
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Lepidópteros
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
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Humans
Idioma:
En
Revista:
Med Mycol
Assunto da revista:
MEDICINA VETERINARIA
/
MICROBIOLOGIA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Reino Unido