title: Genotypic diversity and virulence traits of Streptococcus mutans in caries-free and caries-active individuals.
abstract: The present study evaluated the relationship between clonal diversity and some virulence traits of Streptococcus mutans isolated from eight caries-free and eight caries-active subjects. A total of 155 S. mutans isolates from caries-free subjects and 144 isolates from caries-active subjects were obtained from samples of saliva, dental plaque and tongue surface and identified by PCR. The isolates were submitted to arbitrarily primed (AP)-PCR (OPA-2 and OPA-13) and multilocus enzyme electrophoresis (MLEE) to establish the genotypic diversity. Production of water-insoluble glucan (WIG) (monitored by SDS-PAGE), final pH of cultures and the ability of bacterial cells to adhere to smooth glass in the presence of sucrose were measured. High and comparable abilities of MLEE and AP-PCR were found to distinguish S. mutans genotypes, using Simpson's index of discrimination (0.971 and 0.968, respectively). The results showed a significant difference (P < 0.01) in the number of genotypes when caries-free and caries-active groups were compared by both fingerprinting methods used. Final pH (P = 0.32) and the percentage of adherence to a glass surface (P = 0.62) did not show differences between the two groups; however, the intensities of WIG bands from the caries-active group were greater than those from the caries-free group (P < 0.01). In addition, WIG was positively correlated with the ability of S. mutans to adhere to a glass surface (r = 0.34, P = 0.02) from caries-active subjects. These data showed that AP-PCR analysis and MLEE are both effective methods for assessing the genetic relatedness of S. mutans. Using these techniques, it was found that there is a larger number of genotypes of S. mutans with increased ability to synthesize WIG in caries-active individuals.
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Marcelo Henrique
authors.initials: MH
authors.lastname: Napimoga
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Regianne Umeko
authors.initials: RU
authors.lastname: Kamiya
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Rosimeire Takaki
authors.initials: RT
authors.lastname: Rosa
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Edvaldo AntonioR
authors.initials: EA
authors.lastname: Rosa
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: José Francisco
authors.initials: JF
authors.lastname: Höfling
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: de Oliveira Mattos-Graner
authors.affiliation: Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Reginaldo Bruno
authors.initials: RB
authors.lastname: Gonçalves
mesh_terms: D000293:Adolescent; D000328:Adult; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000032:analysis; D015373:Bacterial Typing Techniques; D003470:Culture Media / Q000737:chemistry; D016172:DNA Fingerprinting; D003731:Dental Caries / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D004798:Enzymes / Q000032:analysis; D014644:Genetic Variation; D005936:Glucans / Q000096:biosynthesis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010449:Peptide Mapping; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D014059:Tongue / Q000382:microbiology; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D004798:Enzymes; D005936:Glucans; D037521:Virulence Factors