Genotypic diversity and virulence traits of Streptococcus mutans in caries-free and caries-active individuals

• Published in: Journal of medical microbiology Vol. 53; no. 7; pp. 697 - 703
• Main Authors: Napimoga, Marcelo Henrique, Kamiya, Regianne Umeko, Rosa, Rosimeire Takaki, Rosa, Edvaldo AntonioR, Hofling, Jose Francisco, de Oliveira Mattos-Graner, Renata, Goncalves, Reginaldo Bruno
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.07.2004; Society for General Microbiology
• Subjects: Adolescent; Adult; Bacterial Adhesion; Bacterial Proteins - analysis; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Culture Media - chemistry; Dental Caries - microbiology; Dental Plaque - microbiology; DNA Fingerprinting; Enzymes - analysis; Fundamental and applied biological sciences. Psychology; Genetic Variation; Glucans - biosynthesis; Humans; Hydrogen-Ion Concentration; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Peptide Mapping; Polymerase Chain Reaction; Saliva - microbiology; Streptococcus mutans; Streptococcus mutans - genetics; Streptococcus mutans - isolation & purification; Streptococcus mutans - pathogenicity; Tongue - microbiology; Virulence; Virulence Factors - genetics; Virulence Factors - physiology; Streptococcaceae; Bacteria; Micrococcales; Microbiology; Virulence; Streptococcus mutans
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/jmm.0.05512-0

Department of Oral Diagnostics, Faculty of Dentistry of Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil Correspondence Reginaldo Bruno Gonçalves reginald{at}fop.unicamp.br Received October 20, 2003 Accepted January 21, 2004 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. Abbreviations: AP-PCR, arbitrarily primed PCR; GTF, glucosyltransferase; MLEE, multilocus enzyme electrophoresis; WIG, water-insoluble glucan.