Effect of dextransucrase antibodies on biofilm formation and certain cariogenic activities in Streptococcus mutans.

Introduction. Dextransucrase produced by Streptococcus mutans plays a vital role in the formation of dental caries by synthesizing exopolysaccharides from sucrose, which helps in the attachment of microbes to the tooth surface, causing caries. Exploring antibody production against S. mutans antigens could be an effective method to protect against dental caries.Hypothesis. Dextransucrase antibodies may help in the prevention of caries formation by inhibiting essential cariogenic factors.Aims. The aim of this study was to investigate the effects of dextransucrase antibodies on biofilm formation and certain associated cariogenic factors of S. mutans.Methodology. Dextransucrase was purified from culture of S. mutans. The antisera against the enzyme were raised in rabbits. The effect of dextransucrase antibodies on biofilm formation was studied using scanning electron microscopy, fluorescence microscopy and quantitative real-time polymerase chain reaction. The effects of the antibodies on associated cariogenic factors were examined using established methods. The cross-reactivity of antibodies with human lung, liver, heart, thyroid and kidney tissues was evaluated by immunohistochemistry.Results. Our findings showed impaired biofilm formation in S. mutans in the presence of dextransucrase antibodies. Genes associated with biofilm formation such as gtfB, gtfC, brpA, relA, Smu.630 and vicK were downregulated (50-97 %) by dextransucrase antibodies in S. mutans. The adherence of S. mutans to glass surface was reduced by 58 % and hydrophobicity was reduced by 55.2 % in the presence of the antibodies compared to the controls. Immunohistochemistry studies revealed no cross-reactivity of human tissues with dextransucrase antibodies.Conclusions. These findings suggest that antibodies raised against dextransucrase exhibit a profound inhibitory effect on biofilm formation and vital cariogenic factors of S. mutans, which supports the contention that dextransucrase could be a promising antigen to study for its anticariogenic potential.

Antibodies generated against dextransucrase exhibit potential anticariostatic properties in Streptococcus mutans.

Streptococcus mutans is a common principal causative agent of dental caries. In this communication, we describe that the antibodies raised against purified dextransucrase effectively inhibited the growth of S. mutans. The purified enzyme showed 58-fold enrichment, 17.5% yield and a specific activity of 3.96 units/mg protein. Purified IgG fraction of the antibody showed significant affinity with the antigenic protein. Immunotritation of the enzyme with dextransucrase antibody showed a gradual increase in inhibition of dextransucrase activity. The growth of S. mutans was also inhibited by 85% in the presence of 28 µg of IgG fraction of the antibody. Antibodies also impaired glucosyltransferase activity (72.8%) and biofilm formation by 92.6% in S. mutans. Western blot analysis revealed no cross reactivity with the various tissues of mice, rat, rabbit and humans. Dot blot analysis showed little reactivity with Lactobacillus acidophilus and Staphylococcus aureus and there was no reactivity with other bacterial strains like Enterococcus faecalis, Escherichia coli and Salmonella typhimurium. These findings suggest that antibody raised against dextransucrase exhibit inhibitory effects on the growth of S. mutans and biofilm formation with no reactivity with various mammalian tissues, thus it could be an effective anticariogenic agent.