In vitro Evaluation of Non-synthetic Compounds against Biofilm of Streptococcus mutans

Authors: Anna Goc, Aleksandra Niedzwiecki, Matthias Rath

Presented at: ASM Microbe 2017; June 1–5, 2017 | New Orleans, LA

Published in: ASM Microbe 2017 Final Program; Poster # FRIDAY-300

Abstract: Dental caries is known as one the most widespread bacterial infection in humans. The prevalent etiological factor is the colonization by pathogenic bacteria and formation by them as biofilm on the surface of teeth. A number of antibiotics have been evaluated for the eradication of dental biofilms, but few have shown the efficacy. Streptococcus mutans occur in the human oral cavity, in plaque biofilms, and is a key pathogen for caries. To address the need for novel antimicrobial agents effective against the biofilms oral pathogens, we have tested over 50 non-synthetic compounds in vitro against cariogenic Streptococcus mutans biofilm. In addition, dominance of EPS-rich matrix that forms the core of the biofilm, while facilitating the creation of localized acidic microenvironments at the biofilm-tooth interface, was examined as well. The minimal biofilm inhibitory concentration of tested compounds against biofilm of Streptococcus mutans after 24 hours revealed that its formation was prevented in 90% when R-carvon, an active constituent of spearmint oil and linolenic acid was added to the media at a concentration of 0.75% (vol/vol), respectively, whereas 0.65% (vol/vol) of tea tree oil and 2.5% (vol/vol) of Helichrysum italicum extract have eradicated 80% of mature biofilm. Moreover, treatments with these agents significantly disrupted EPS content within biofilms validating anti-biofilm action of these compounds. Therefore, we concluded that these agents could play an important role in the development of alternative or adjunctive anti-biofilm and anti-caries therapeutics.