Application of matrix assisted laser desorption ionization time-of-flight mass spectrometry in rapid identification of clinical infectious aspergillus

Abstract

Objective To explore the value applying matrix assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS, VITEK MS V 3.0) in the identification of clinical invasive aspergillosis. Methods Aspergilli were isolated from the specimens of patients with clinical invasive aspergillus infection and cultured purely under different culture conditions. The aspergilli were identified by MALDI-TOF MS technique and traditional morphological identification technique. The results of the identification were compared. Results The 88 strains were cultured in Sabouraud dextrose liquid medium, Sabouraud dextrose agar medium, and Chalet agar medium; the accuracies of the identification by MALDI-TOF MS technology were 95.74%, 95.45%, and 95.17% and those by traditional morphological technology were 82.10%, 86.08%, and 81.82%, with statistical differences in the accuracies of the identification cultured in different culture media (χ2=136.936, P=0.000; χ2=75.918, P=0.000; χ2=122.612, P=0.000). The 88 strains were cultured for 48, 72, 96, and 120 h, the accuracies of the identification by MALDI-TOF MS technology were 90.15%, 97.35%, 97.35%, and 96.97% and those by traditional morphological technology 77.27%, 82.58%, 85.23%, and 88.26%, with statistical differences in the accuracies of the identification in different culture times (χ2=65.824, P=0.000; χ2=132.021, P=0.000; χ2=93.598, P=0.000; χ2=61.382, P=0.000). Conclusion The accuracy of the identification of Aspergillus by MALDI-TOF MS technology is higher than that by traditional morphological technology; and MALDI-TOF MS technology can be popularized in the identification of clinical invasive aspergillosis. Key words: Matrix assisted laser desorption/ionization time-of-flight mass spectrometry; MALDI-TOF MS; Traditional morphological identification technique; Aspergillus