TY - JOUR
T1 - Quality of MALDI-TOF Mass Spectra in Routine Diagnostics
T2 - Results from an International External Quality Assessment including 36 Laboratories from 12 countries using 47 challenging bacterial strains
AU - for the ESGMD study group
AU - Cuénod, Aline
AU - Aerni, Martina
AU - Bagutti, Claudia
AU - Bayraktar, Banu
AU - Boz, Efe Serkan
AU - Carneiro, Cynthia Beisert
AU - Casanova, Carlo
AU - Coste, Alix T.
AU - Damborg, Peter
AU - van Dam, Dirk W.
AU - Demirci, Mehmet
AU - Drevinek, Pavel
AU - Dubuis, Olivier
AU - Fernandez, José
AU - Greub, Gilbert
AU - Hrabak, Jaroslav
AU - Hürkal Yiğitler, Gülen
AU - Hurych, Jakub
AU - Jensen, Thøger Gorm
AU - Jost, Géraldine
AU - Kampinga, Greetje A.
AU - Kittl, Sonja
AU - Lammens, Christine
AU - Lang, Claudia
AU - Lienhard, Reto
AU - Logan, Julie
AU - Maffioli, Carola
AU - Mareković, Ivana
AU - Marschal, Matthias
AU - Moran-Gilad, Jacob
AU - Nolte, Oliver
AU - Oberle, Michael
AU - Pedersen, Michael
AU - Pflüger, Valentin
AU - Pranghofer, Sigrid
AU - Reichl, Julia
AU - Rentenaar, Rob J.
AU - Riat, Arnaud
AU - Rodríguez-Sánchez, Belén
AU - Schilt, Camille
AU - Schlotterbeck, Ann Kathrin
AU - Schrenzel, Jacques
AU - Troib, Shani
AU - Willems, Elise
AU - Wootton, Mandy
AU - Ziegler, Dominik
AU - Egli, Adrian
N1 - Funding Information:
We thank Dr. Vladimira Hinic, Dr. Fanny Wegner, Dr. Helena Seth-Smith, and Dr. Marco Meola for valuable feedback on this manuscript. We thank Valerie Courtet and Daniel Gander (University Hospital of Basel, Basel, Switzerland); Dr. Orli Sagi and Dr. Boris Khalfin (Soroka University Medical Center, Beersheva, Israel); Manja Ipsen Hanegård and Tony Bønnelycke (University of Copenhagen, Copenhagen, Denmark); Ivana Jozić and Neno Petrić (University Hospital Centre Zagreb, Croatia); Alison Kolaru and Milena Antuskova (Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic); Stefanie Müller, Simon Feyer and Estelle Gohl (Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland); Jris Wyss (Institute for Infectious Diseases, University of Bern, Switzerland); Myriam Corthesy (Institute of Microbiology, University Hospital Lausanne, Switzerland); Eliane Haessler, Michael Trouessin and Pierre Glükler (Viollier AG) and Annette Wittmers (University Hospital Freiburg, Freiburg im Breisgau, Germany), Roxanne Mouchet and Dr. Samuel Lüdin (Mabritec AG) for technical support and acquiring MALDI-TOF mass spectra at their respective centre. Further, we would like to thank Dr. Victoria Girard (bioMérieux, Marcy l’Étoile, France) for providing us access to the VitekMS database and technical consultancy as well as Ilona Mossbrugger (Bruker Daltonics, Bremen, Germany) for technical consultancy.
Funding Information:
This study was supported by the two Cantons of Basel through a D-BSSE-Uni-Basel Personalised Medicine grant from the ETH Zurich (PMB-03-17, A.C. and A.E.) and a Doc.Mobility fellowship by the Swiss National Science Foundation (P1BSP3-184342, A.C.).
Publisher Copyright:
© 2022 The Authors
PY - 2023/2/1
Y1 - 2023/2/1
N2 - OBJECTIVE: MALDI-TOF MS is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are: number of detected marker masses, reproducibility, and measurement precision. We aimed to assess MSQs across diagnostic laboratories and the potential of simple workflow adaptations to improve it.METHODS: For baseline MSQ assessment, 47 diverse bacterial strains which are challenging to identify by MALDI-TOF MS, were routinely measured in 36 laboratories from 12 countries, and well defined MSQ features were used. After an intervention consisting of detailed reported feedback and instructions on how to acquire MALDI-TOF mass spectra, measurements were repeated and MSQs were compared.RESULTS: At baseline, we observed heterogeneous MSQ between the devices, considering the median number of marker masses detected (range = [5, 25]), reproducibility between technical replicates (range = [55%, 86%]), and measurement error (range = [147 parts per million (ppm), 588ppm]). As a general trend, the spectral quality was improved after the intervention for devices which yielded low MSQs in the baseline assessment: for 4/5 devices with a high measurement error, the measurement precision was improved (p-values<0.001, paired Wilcoxon test); for 6/10 devices, which detected a low number of marker masses, the number of detected marker masses increased (p-values<0.001, paired Wilcoxon test).CONCLUSION: We have identified simple workflow adaptations, which, to some extent, improve MSQ of poorly performing devices and should be considered by laboratories yielding a low MSQ. Improving MALDI-TOF MSQ in routine diagnostics is essential for increasing the resolution of bacterial identification by MALDI-TOF MS, which is dependent on the reproducible detection of marker masses. The heterogeneity identified in this EQA requires further study.
AB - OBJECTIVE: MALDI-TOF MS is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are: number of detected marker masses, reproducibility, and measurement precision. We aimed to assess MSQs across diagnostic laboratories and the potential of simple workflow adaptations to improve it.METHODS: For baseline MSQ assessment, 47 diverse bacterial strains which are challenging to identify by MALDI-TOF MS, were routinely measured in 36 laboratories from 12 countries, and well defined MSQ features were used. After an intervention consisting of detailed reported feedback and instructions on how to acquire MALDI-TOF mass spectra, measurements were repeated and MSQs were compared.RESULTS: At baseline, we observed heterogeneous MSQ between the devices, considering the median number of marker masses detected (range = [5, 25]), reproducibility between technical replicates (range = [55%, 86%]), and measurement error (range = [147 parts per million (ppm), 588ppm]). As a general trend, the spectral quality was improved after the intervention for devices which yielded low MSQs in the baseline assessment: for 4/5 devices with a high measurement error, the measurement precision was improved (p-values<0.001, paired Wilcoxon test); for 6/10 devices, which detected a low number of marker masses, the number of detected marker masses increased (p-values<0.001, paired Wilcoxon test).CONCLUSION: We have identified simple workflow adaptations, which, to some extent, improve MSQ of poorly performing devices and should be considered by laboratories yielding a low MSQ. Improving MALDI-TOF MSQ in routine diagnostics is essential for increasing the resolution of bacterial identification by MALDI-TOF MS, which is dependent on the reproducible detection of marker masses. The heterogeneity identified in this EQA requires further study.
KW - Bacterial species identification
KW - Diagnostic performance external quality assessment
KW - MALDI-TOF MS
KW - Quality control
KW - Standardisation
UR - http://www.scopus.com/inward/record.url?scp=85134840447&partnerID=8YFLogxK
U2 - 10.1016/j.cmi.2022.05.017
DO - 10.1016/j.cmi.2022.05.017
M3 - Article
C2 - 35623578
SN - 1198-743X
VL - 29
SP - 190
EP - 199
JO - Clinical Microbiology and Infection
JF - Clinical Microbiology and Infection
IS - 2
ER -