Saltos Rosero Nancy, Torres Corral Yolanda, Fernández Álvarez Clara, Aguilera Guirao Antonio, Seoane Prado Rafael, Santos Ysabel
Departamento de Microbiología y Parasitología, Instituto de Análisis Químico y Biológico (IAQBUS), Universidad de Santiago de Compostela, Campus Vida, C/Constantino Candeira S/N, 15782, Santiago de Compostela, Spain.
Departamento de Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
Appl Microbiol Biotechnol. 2020 Dec;104(24):10601-10612. doi: 10.1007/s00253-020-10980-7. Epub 2020 Nov 3.
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.
本研究评估了基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）结合统计工具与基于聚合酶链反应（PCR）的技术相比，用于变形链球菌鉴定的可靠性。使用变形链球菌种属和血清型特异性引物，通过常规PCR对细菌分离株进行鉴定和血清分型。对于细菌鉴定，将变形链球菌和其他链球菌的质谱数据与Biotyper V 3.1数据库进行比较，并通过聚类分析和主成分分析（PCA）检查质谱峰列表。使用UniProtKB/Swiss-Prot和UniProtKB/TrEMBL数据库以及NCBI数据库的BLAST工具进行潜在生物标志物的鉴定。PCR鉴定出100%的分离株为变形链球菌。变形链球菌菌株被分型为血清型c（85.6%）、e（8.6%）、k（4.8%）和f（0.9%）。尽管Biotyper数据库仅能在种水平鉴定70%的测试菌株，但质谱峰的PCA和聚类分析能鉴定出100%的变形链球菌分离株，并将其与其他口腔和非口腔链球菌区分开来。质荷比为9572.73的一个质谱峰被鉴定为变形链球菌的种特异性生物标志物。未鉴定出变形链球菌血清型的生物标志物。要点：• MALDI-TOF MS结合统计工具用于变形链球菌的鉴定。• 通过MALDI-TOF MS检测种属鉴定生物标志物。• 对唾液样本中的变形链球菌进行PCR鉴定和血清分型。
