Identification of <i>Elizabethkingia</i> species by MALDI-TOF MS proteotyping

<i>Elizabethkingia</i> species are groups of emerging opportunistic bacterial pathogens with a high mortality rate, causing healthcare-associated outbreaks worldwide. Rapid identification of <i>Elizabethkingia</i> species is important becausethese species show intrinsically carbapenem resistance and there are few data for using appropriate antibiotics. Until now, only whole-genome sequencing could accurately identify the seven <i>Elizabethkingia</i> species. Therefore, establishing rapid and accurate identification methods for <i>Elizabethkingia</i> species in clinical laboratories is vital. In this study, we developed new methods for identifying <i>Elizabethkingia</i> species using four biomarker protein peaks-ribosomal L29, L30, S21, and the YtxH domain-containing proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) proteotyping. This study demonstrates the potential of routine MALDI-TOF MS -based laboratory examination for the early identification of <i>Elizabethkingia</i> species.