title: Phenotypic heterogeneity of Streptococcus mutans in dentin.
abstract: Information concerning phenotypic heterogeneity of Streptococcus mutans in carious dentin is sparse. Matrix-assisted laser-desorption/ionization-time-of-flight mass-spectrometry (MALDI-TOF-MS) facilitates the phenotypic differentiation of bacteria to the subspecies level. To verify a supposed influence of restorative treatment on the phenotypic heterogeneity of S. mutans, we isolated and compared a total of 222 S. mutans strains from dentin samples of 21 human deciduous molars during caries excavation (T(1)) and 8 wks (T(2)) after removal of the temporary restoration. Phenotypic heterogeneity was determined by MALDI-TOF-MS and hierarchical clustering. Thirty-six distinct S. mutans phenotypes could be identified. Although indistinguishable phenotypes were found in the same teeth at T(1) and T(2), as well as in different teeth of individual participants, the phenotypic heterogeneity increased significantly, from 1.4 phenotypes per S. mutans-positive dentin sample at T(1) to 2.2 phenotypes at T(2). We attribute this to an adaptation of S. mutans to the modified environment under the restoration following caries excavation.
authors.affiliation: Department of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University, D-66421 Homburg, Germany. Stefan.Rupf@uniklinikum-saarland.de
authors.forename: S
authors.initials: S
authors.lastname: Rupf
authors.forename: M
authors.initials: M
authors.lastname: Hannig
authors.forename: K
authors.initials: K
authors.lastname: Breitung
authors.forename: W
authors.initials: W
authors.lastname: Schellenberger
authors.forename: K
authors.initials: K
authors.lastname: Eschrich
authors.forename: T
authors.initials: T
authors.lastname: Remmerbach
authors.forename: S
authors.initials: S
authors.lastname: Kneist
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D002648:Child; D015169:Colony Count, Microbial; D003731:Dental Caries / Q000382:microbiology / Q000628:therapy; D003737:Dental Cavity Preparation / Q000379:methods; D003794:Dental Restoration, Temporary; D003804:Dentin / Q000382:microbiology*; D005500:Follow-Up Studies; D018740:Genetic Heterogeneity; D005899:Glass Ionomer Cements; D018698:Glutamic Acid / Q000627:therapeutic use; D006801:Humans; D007930:Leucine / Q000627:therapeutic use; D008239:Lysine / Q000627:therapeutic use; D008963:Molar / Q000382:microbiology; D010641:Phenotype; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013295:Streptococcus mutans / Q000145:classification / Q000235:genetics*; D014094:Tooth, Deciduous / Q000382:microbiology
chemical_list: C119934:Carisolv; D005899:Glass Ionomer Cements; C061499:Ketac-Bond; D018698:Glutamic Acid; D007930:Leucine; D008239:Lysine