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Published on: May 28, 2014
[MALDI-TOF mass spectrometry: Evaluation of the preanalytical phase for identification of molds]
Ivana Maldonado1, Dolores García Ramírez1, Pablo Striebeck1
1Laboratorio de Microbiología, Hospital Alemán, Ciudad Autónoma de Buenos Aires, Argentina.
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).
Insights
Zirconium extraction (ZE) significantly improved mold identification using MALDI-TOF MS compared to water extraction (WE) and the provider
Area of Science:
- Microbiology
- Analytical Chemistry
- Biotechnology
Background:
- Accurate identification of mold species is crucial for various applications, including clinical diagnostics, food safety, and industrial processes.
- Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is a powerful technique for microbial identification.
- Optimizing protein extraction methodologies is key to maximizing the performance of MALDI-TOF MS for mold identification.
Purpose of the Study:
- To evaluate and compare the efficacy of three distinct protein extraction methods for mold identification using MALDI-TOF MS.
- To determine the optimal protein extraction strategy for enhancing the accuracy and reliability of mold identification.
- To assess the impact of different protein extraction techniques on correct identification rates at both genus and species levels.
Main Methods:
- Evaluated three protein extraction methodologies: water extraction (WE), zirconium extraction (ZE), and provider's recommended method (PRM).
- Tested methodologies on 44 mold isolates.
- Compared results using two databases: Bruker (BK) and Bruker+National Institutes of Health (NIH).
Main Results:
- Zirconium extraction (ZE) demonstrated superior performance, yielding higher correct identification (CI) rates at both genus and species levels compared to WE and PRM across both databases.
- ZE resulted in significantly fewer non-reliable identifications and a lower number of isolates with no observed peaks.
- Specifically, ZE achieved CI at species level for 17/20 isolates (Bruker+NIH database), outperforming WE (5/7) and PRM (11/14).
Conclusions:
- Zirconium extraction (ZE) is the most effective protein extraction method for optimizing mold identification using MALDI-TOF MS.
- The ZE method significantly enhances the accuracy and reliability of mold identification compared to conventional methods.
- This optimized extraction technique holds promise for improving routine microbial identification workflows in diagnostic and research settings.
Related Concept Videos
01:19MALDI-TOF Mass Spectrometry
01:08Matrix-Assisted Laser Desorption Ionization (MALDI)