title: Inhibitory Effect ofLactococcus lactisHY 449 on Cariogenic Biofilm.
abstract: Dental caries is caused by cariogenic biofilm, an oral biofilm includingStreptococcus mutans. Recently, the prevention of dental caries using various probiotics has been attempted.Lactococcus lactisHY 449 is a probiotic bacterium. The aim of this study was to investigate the effect ofL. lactisHY 449 on cariogenic biofilm and to analyze its inhibitory mechanisms. Cariogenic biofilm was formed in the presence or absence ofL. lactisHY 449 andL. lactisATCC 19435, and analyzed with a confocal laser microscope. The formation of cariogenic biofilm was reduced in cultures spiked with bothL. lactisstrains, andL. lactisHY 449 exhibited more inhibitory effects thanL. lactisATCC 19435. In order to analyze and to compare the inhibitory mechanisms, the antibacterial activity of the spent culture medium from bothL. lactisstrains againstS. mutanswas investigated, and the expression of glucosyltransferases (gtfs) ofS. mutanswas then analyzed by real-time RT-PCR. In addition, the sucrose fermentation ability of bothL. lactisstrains was examined. BothL. lactisstrains showed antibacterial activity and inhibited the expression ofgtfs, and the difference between both strains did not show. In the case of sucrose-fermenting ability,L. lactisHY 449 fermented sucrose butL. lactisATCC 19435 did not.L. lactisHY 449 inhibited the uptake of sucrose and thegtfsexpression ofS. mutans, whereby the development of cariogenic biofilm may be inhibited. In conclusion,L. lactisHY 449 may be a useful probiotic for the prevention of dental caries.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Oral Microbiology and Immunology, College of Dentistry, Dankook University, Cheonan 31116, Republic of Korea.
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000898:Antibiosis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D003731:Dental Caries / Q000382:microbiology* / Q000517:prevention & control*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D013294:Lactococcus lactis / Q000502:physiology*; D019936:Probiotics / Q000378:metabolism; D013295:Streptococcus mutans / Q000201:enzymology / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D005964:Glucosyltransferases
keywords: Lactococcus lactis; Streptococcus mutans; antibiofilm effects; cariogenic biofilm; probiotics