title: [Identification of Streptococcus mutans in carious patients' saliva samples by MALDI-TOF mass spectrometry].
abstract: OBJECTIVE
  To identify Streptococcus mutans (S. mutans) in carious patients' saliva using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and to establish a faster and more accurate method to identify S. mutans.
  
  
  METHODS
  In this study, a total of 90 carious patients from Department of Endodontics of Peking University School of Stomatology were recruited. All these patients' saliva was collected. After extracting the protein of the samples, they were identified by MALDI-TOF MS. The composite profile was analyzed using BioExplorer 1.0 software. The scores ≥ 25 were considered as S. mutans, whereas the scores <25 were as considered as non S. mutans. Finally, these results were compared with 16S rDNA sequencing to figure out the sensitivity and concordance rate, respectively.
  
  
  RESULTS
  The sensitivity of MALDI-TOF MS was 96.0%, and the concordance rate compared with 16S rDNA sequencing was as high as 98.7%.
  
  
  CONCLUSIONS
  MALDI-TOF MS is high throughput, rapid and easy to perform in comparison to other conventional methods. It has a high sensivity and concordance rate. Thus, MALDI-TOF MS can serve as an effective tool for identification of S. mutans.
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Ren
authors.affiliation: Central Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Central Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Yi-fei
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: Central Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Endodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Endodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Ying-yi
authors.initials: YY
authors.lastname: Liu
authors.affiliation: Department of Endodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Chong-yang
authors.initials: CY
authors.lastname: Yuan
authors.affiliation: Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
authors.forename: Qing-wei
authors.initials: QW
authors.lastname: Ma
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Shu-guo
authors.initials: SG
authors.lastname: Zheng
mesh_terms: D003731:Dental Caries / Q000382:microbiology*; D006801:Humans; D012463:Saliva / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013295:Streptococcus mutans / Q000302:isolation & purification*