Rapid identification of moulds and arthroconidial yeasts from positive blood cultures by MALDI-TOF mass spectrometry.
Moulds and arthroconidial yeasts are potential life-threatening agents of fungemia in immunocompromised patients. Fast and accurate identification (ID) of these pathogens hastens initiation of targeted antifungal therapy, thereby improving the patients' prognosis. We describe a new strategy that enabled the identification of moulds and arthroconidial yeasts directly from positive blood cultures by MALDI-TOF mass spectrometry (MS). Positive blood cultures (BCs) with Gram staining showing hyphae and/or arthroconidia were prospectively selected and submitted to an in-house protein extraction protocol. Mass spectra were obtained by Vitek MS™ system, and identifications were carried out with in the research use only (RUO) mode with an extended database (SARAMIS™ [v.4.12] plus in-house database). Fusarium solani, Fusarium verticillioides, Exophiala dermatitidis, Saprochaete clavata, and Trichosporon asahii had correct species ID by MALDI-TOF MS analysis of positive BCs. All cases were related to critically ill patients with high mortality fungemia and direct ID from positive BCs was helpful for rapid administration of targeted antifungal therapy.
Central Laboratory Division-LIM03, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil Laboratory of Medical Mycology - LIM-53, Hospital das Clínicas da FMUSP and Instituto de Medicina Tropical, Universidade de São Paulo, Brazil jnaj99@gmail.com.
João N
JN
de Almeida
Children's Institute, Hospital das Clínicas Faculdade de Medicina da Universidade de São Paulo, Brazil.
Jaques
J
Sztajnbok
Central Laboratory Division-LIM03, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil.
Afonso Rafael
AR
da Silva
Children's Institute, Hospital das Clínicas Faculdade de Medicina da Universidade de São Paulo, Brazil.
Vinicius Adriano
VA
Vieira
Children's Institute, Hospital das Clínicas Faculdade de Medicina da Universidade de São Paulo, Brazil.
Anne Layze
AL
Galastri
Laboratory of Bacteriology-LIM54, Instituto de Medicina Tropical, Universidade de São Paulo, Brazil.
Leandro
L
Bissoli
Children's Institute, Hospital das Clínicas Faculdade de Medicina da Universidade de São Paulo, Brazil.
Nadia
N
Litvinov
Laboratory of Medical Mycology - LIM-53, Hospital das Clínicas da FMUSP and Instituto de Medicina Tropical, Universidade de São Paulo, Brazil.
Gilda Maria Barbaro
GM
Del Negro
Central Laboratory Division-LIM03, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil.
Adriana Lopes
AL
Motta
Central Laboratory Division-LIM03, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil.
Flávia
F
Rossi
Laboratory of Medical Mycology - LIM-53, Hospital das Clínicas da FMUSP and Instituto de Medicina Tropical, Universidade de São Paulo, Brazil.
Gil
G
Benard
D000293:Adolescent; D000368:Aged; D000071997:Blood Culture / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D016469:Fungemia / Q000175:diagnosis*; D005658:Fungi / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors
MALDI-TOF mass spectrometry; Mould; athroconidial yeasts; blood culture; fungemia