AUTHOR=Yu Keyi , Huang Zhenzhou , Li Ying , Fu Qingbo , Lin Lirong , Wu Shiyao , Dai Hang , Cai Hongyan , Xiao Yue , Lan Ruiting , Wang Duochun 

TITLE=Establishment and Application of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Detection of Shewanella Genus

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.625821

DOI=10.3389/fmicb.2021.625821

ISSN=1664-302X

ABSTRACT=<p><italic>Shewanella</italic> species are widely distributed in the aquatic environment and aquatic organisms. They are opportunistic human pathogens with increasing clinical infections reported in recent years. However, there is a lack of a rapid and accurate method to identify <italic>Shewanella</italic> species. We evaluated here matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid identification of <italic>Shewanella.</italic> A peptide mass reference spectra (PMRS) database was constructed for the type strains of 36 <italic>Shewanella</italic> species. The main spectrum projection (MSP) cluster dendrogram showed that the type strains of <italic>Shewanella</italic> species can be effectively distinguished according to the different MS fingerprinting. The PMRS database was validated using 125 <italic>Shewanella</italic> test strains isolated from various sources and periods; 92.8% (<italic>n</italic> = 116) of the strains were correctly identified at the species level, compared with the results of multilocus sequence analysis (MLSA), which was previously shown to be a method for identifying <italic>Shewanella</italic> at the species level. The misidentified strains (<italic>n</italic> = 9) by MALDI-TOF MS involved five species of two groups, i.e., <italic>Shewanella algae</italic>–<italic>Shewanella chilikensis</italic>–<italic>Shewanella indica</italic> and <italic>Shewanella seohaensis</italic>–<italic>Shewanella xiamenensis</italic>. We then identified and defined species-specific biomarker peaks of the 36 species using the type strains and validated these selected biomarkers using 125 test strains. Our study demonstrated that MALDI-TOF MS was a reliable and powerful tool for the rapid identification of <italic>Shewanella</italic> strains at the species level.</p>