title: Genotypic and phenotypic analysis of S. mutans isolated from dental biofilms formed in vivo under high cariogenic conditions.
abstract: The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.
authors.affiliation: Piracicaba Dental School, UNICAMP - University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Rodrigo Alex
authors.initials: RA
authors.lastname: Arthur
authors.forename: Altair Antoninha Del Bel
authors.initials: AA
authors.lastname: Cury
authors.forename: Renata Oliveira Mattos
authors.initials: RO
authors.lastname: Graner
authors.forename: Pedro Luiz
authors.initials: PL
authors.lastname: Rosalen
authors.forename: Gláuber Campos
authors.initials: GC
authors.lastname: Vale
authors.forename: Adriana Franco
authors.initials: AF
authors.lastname: Paes Leme
authors.forename: Jaime Aparecido
authors.initials: JA
authors.lastname: Cury
authors.forename: Cínthia Pereira Machado
authors.initials: CP
authors.lastname: Tabchoury
mesh_terms: D000143:Acids; D000293:Adolescent; D000328:Adult; D025243:Bacterial Proton-Translocating ATPases / Q000032:analysis; D018441:Biofilms; D002326:Cariogenic Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D003741:Dental Deposits / Q000382:microbiology; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006019:Glycolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability; D009055:Mouth / Q000382:microbiology*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D013395:Sucrose / Q000008:administration & dosage*; D013997:Time Factors; D014774:Virulence; D014867:Water / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D000143:Acids; D002326:Cariogenic Agents; D014867:Water; D013395:Sucrose; D025243:Bacterial Proton-Translocating ATPases