Identification of Uncommon Pathogenic Bacteria by MALDI-TOF Mass Spectrometry Using a Custom Library of Siriraj Hospital

Objective: Matrix Assisted Laser Desorption Ionization Time-Of-Flight mass spectrometry (MALDI-TOF MS) is a rapid and cost-effective technique that serves as an alternative method for bacterial identification in microbiology laboratories. This study aimed to determine the performance of MALDI-TOF MS for identifying uncommon and/ or fastidious bacteria comparing with automated identification method. Methods: We observed the performances of original and extended databases after adding of in-house MALDI-TOF MS database for a total of 54 isolates belonging to 16 genera of uncommon and/or fastidious bacteria. Results: The extended database improved identification of these bacteria significantly except for Listeria monocytogenes and Elizabethkingia meningoseptica. Conclusion: This study provides a possibility for identification of uncommon and/or fastidious bacteria by MALDI- TOF MS method