[MALDI-TOF mass spectrometry: Evaluation of the preanalytical phase for identification of molds]

Abstract

In order to optimize the identification of molds with MALDI-TOF MS, three protein extraction-methodologies were evaluated against 44 isolates: water extraction (WE), zirconium extraction (ZE) and the provider's recommended method (PRM). Two data bases were compared, Bruker (BK) and Bruker+National Institutes of Health. Considering both databases, results were respectively as follows: correct identification (CI) at gender level, 10 and 16 by WE; 27 and 32 by ZE and 18 and 23 by PRM; CI at species level, 5 and 7 by WE; 17 and 20 by ZE and 11 and 14 by PRM; non-reliable identification, 18 and 12 by WE; 9 and 4 by ZE and by PRM. No peaks were observed in 16 by WE, 8 by ZE and 17 by PRM. ZE showed the best perfomance (p<0.05).

Keywords: Espectrometría de masas; Hongos miceliales; Mass spectrometry; Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; Molds.