Validation of a modified algorithm for the identification of yeast isolates using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS)

TY - JOUR

T1 - Validation of a modified algorithm for the identification of yeast isolates using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS)

AU - van Herendael, B.H.

AU - Bruynseels, P.

AU - Bensaid, M.

AU - Boekhout, T.

AU - de Baere, T.

AU - Surmont, I.

AU - Mertens, A.H.

N1 - Reporting year: 2011

PY - 2011

Y1 - 2011

N2 - Optimising antifungal treatment requires the fast and species-specific identification of yeast isolates. We evaluated a modified protocol for the rapid identification of clinical yeast isolates using matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) technology. First, we evaluated a simplified extraction procedure using 54 clinical yeast isolates. Second, we validated a new protocol with this simplified extraction procedure and lower identification threshold by analysing 167 isolates with either MALDI-TOF or conventional identification techniques. MALDI-TOF analysis with both the standard and short extraction procedure yielded identical identification results, although the log-scores were lower with the latter. With the modified protocol, 163/167 (97.6%) isolates showed a correct identification as compared to conventional identification techniques. A total of 135 out of the 163 (82.8%) correct identifications showed log-scores above 1.7, which we considered as the minimum log-score for secure species identification. The rapid identification of clinical yeast isolates is crucial in patient management. The MALDI-TOF technique using a short extraction procedure can be an alternative for the labourious standard procedure, although the log-scores will be lower. The identification of clinical yeast isolates with the modified protocol is a practical and accurate alternative for conventional identification techniques. If the isolate shows a log-score below 1.7, the standard extraction procedure should be used.

AB - Optimising antifungal treatment requires the fast and species-specific identification of yeast isolates. We evaluated a modified protocol for the rapid identification of clinical yeast isolates using matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) technology. First, we evaluated a simplified extraction procedure using 54 clinical yeast isolates. Second, we validated a new protocol with this simplified extraction procedure and lower identification threshold by analysing 167 isolates with either MALDI-TOF or conventional identification techniques. MALDI-TOF analysis with both the standard and short extraction procedure yielded identical identification results, although the log-scores were lower with the latter. With the modified protocol, 163/167 (97.6%) isolates showed a correct identification as compared to conventional identification techniques. A total of 135 out of the 163 (82.8%) correct identifications showed log-scores above 1.7, which we considered as the minimum log-score for secure species identification. The rapid identification of clinical yeast isolates is crucial in patient management. The MALDI-TOF technique using a short extraction procedure can be an alternative for the labourious standard procedure, although the log-scores will be lower. The identification of clinical yeast isolates with the modified protocol is a practical and accurate alternative for conventional identification techniques. If the isolate shows a log-score below 1.7, the standard extraction procedure should be used.

U2 - 10.1007/s10096-011-1383-y

DO - 10.1007/s10096-011-1383-y

M3 - Article

SN - 0934-9723

JO - European Journal of Clinical Microbiology and Infectious Diseases

JF - European Journal of Clinical Microbiology and Infectious Diseases

ER -