title: Effects of combined oleic acid and fluoride at sub-MIC levels on EPS formation and viability of Streptococcus mutans UA159 biofilms.
abstract: Despite the widespread use of fluoride, dental caries, a biofilm-related disease, remains an important health problem. This study investigated whether oleic acid, a monounsaturated fatty acid, can enhance the effect of fluoride on extracellular polysaccharide (EPS) formation by Streptococcus mutans UA159 biofilms at sub-minimum inhibitory concentration levels, via microbiological and biochemical methods, confocal fluorescence microscopy, and real-time PCR. The combination of oleic acid with fluoride inhibited EPS formation more strongly than did fluoride or oleic acid alone. The superior inhibition of EPS formation was due to the combination of the inhibitory effects of oleic acid and fluoride against glucosyltransferases (GTFs) and GTF-related gene (gtfB, gtfC, and gtfD) expression, respectively. In addition, the combination of oleic acid with fluoride altered the bacterial biovolume of the biofilms without bactericidal activity. These results suggest that oleic acid may be useful for enhancing fluoride inhibition of EPS formation by S. mutans biofilms, without killing the bacterium.
authors: a Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience and BK 21 Plus Program , Chonbuk National University , Jeonju , Republic of Korea.
authors: Jian-Na
authors: JN
authors: Cai
authors: Mi-A
authors: MA
authors: Kim
authors: Ji-Eun
authors: JE
authors: Jung
authors: Santosh
authors: S
authors: Pandit
authors: Kwang-Yeob
authors: KY
authors: Song
authors: Jae-Gyu
authors: JG
authors: Jeon
mesh_terms: D018441:Biofilms / Q000187:drug effects*; D002327:Cariostatic Agents / Q000494:pharmacology; D003731:Dental Caries / Q000382:microbiology / Q000517:prevention & control; D004357:Drug Synergism; D005459:Fluorides / Q000494:pharmacology*; D005964:Glucosyltransferases / Q000378:metabolism; D006801:Humans; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D019301:Oleic Acid / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction; D012997:Solvents / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects / Q000502:physiology
chemical_list: D002327:Cariostatic Agents; D012997:Solvents; D019301:Oleic Acid; D005964:Glucosyltransferases; C113848:glucosyltransferase D; D005459:Fluorides
keywords: EPSs; Streptococcus mutans biofilms; combination effect; fluoride; oleic acid