Usefulness of matrix-assisted laser desorption ionization/time of flight mass spectrometry for the identification of Streptococcus mutans

• Published in: Applied microbiology and biotechnology Vol. 104; no. 24; pp. 10601 - 10612
• Main Authors: Saltos Rosero, Nancy, Torres Corral, Yolanda, Fernández Álvarez, Clara, Aguilera Guirao, Antonio, Seoane Prado, Rafael, Santos, Ysabel
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2020; Springer; Springer Nature B.V
• Subjects: Biomarkers; Biomedical and Life Sciences; Biotechnology; Cluster analysis; Genomics; Identification; Identification and classification; Ionization; Ions; Lasers; Life Sciences; Mass spectra; Mass spectrometry; Mass spectroscopy; Microbial Genetics and Genomics; Microbiology; Plasma desorption mass spectrometry; Principal components analysis; Proteomics; Reliability analysis; Reproducibility of Results; Saliva; Serotypes; Serotyping; Species; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Statistical methods; Statistics; Strains (organisms); Streptococcus; Streptococcus infections; Streptococcus mutans; Streptococcus mutans - genetics; Time-of-flight mass spectrometry; Transcriptomics; Spain; Biomarkers; MALDI-TOF MS; identification; Serotype; PCR; Streptococcus mutans identification
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-020-10980-7

This study evaluated the reliability of MALDI-TOF MS coupled with statistical tools for the identification of
Streptococcus mutans
in comparison with PCR-based techniques. Bacterial isolates were identified and serotyped by conventional PCR, using
S. mutans
species and serotype-specific primers. For bacterial identification, mass spectra data from
S. mutans
and other streptococci were compared with Biotyper V 3.1 database and the mass peak lists were examined by cluster and principal component (PCA) analysis. Identification of potential biomarkers was performed using UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases and BLAST tool of the NCBI database. PCR identified 100% of the isolates as
S. mutans
.
S. mutans
strains were typed as serotypes c (85.6%), e (8.6%), k (4.8%), and f (0.9%). Although only the 70% of the strains tested were identified at species level by the Biotyper database, PCA and cluster analysis of mass peaks allowed the identification of 100%
S. mutans
isolates and its differentiation from the other oral and non-oral streptococci. One mass peak at
m/z
value of 9572.73 was identified as species-specific biomarker for
S. mutans
. No biomarkers were identified for
S. mutans
serotypes.
Key points
•
MALDI-TOF MS coupled with statistical tools for the identification of S. mutans.
•
Detection of species identifying biomarkers by MALDI-TOF MS.
•
PCR identification and serotyping of S. mutans from saliva samples.