OBJECTIVEThis study aims to evaluate the antimicrobial activity of decapeptide, a novel antimicrobial peptide, against several major cariogenic and periodontopathogenic bacteria in vitro. METHODS In this study, we investigated the antimicrobial activity of decapeptide against Streptococcus mutans (S. mutans), Streptococcus sobrinus, Lactobacillus acidophilus, Streptococcus sanguis, Streptococcus gordonii, Actinomyces viscosus, Actinomyces naeslundii, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Saccharomyces albicans in vitro using the agar diffusion method and broth dilution method. Furthermore, a time-kill kinetic study of decapeptide against S. mutans was performed.

RESULTSThe results showed that decapeptide exhibited antimicrobial activity against various oral bacteria and fungi. The minimum inhibitory concentration (MIC) of main cariogenic bacteria ranged from 62.5 μg · mL(-1) to 125 μg · mL(-1), and the MIC of periodontopathogenic bacteria tested ranged from 250 μg · mL(-1) to 1,000 μg · mL(-1). Among the bacteria tested, decapeptide had a strong inhibitory effect on cariogenic S. mutans. Results of the time-kill kinetic studies showed that decapeptide reduced the viable counts of S. mutans by more than one order of magnitude after 20 min of incubation, and thoroughly killed S. mutans after 30 min. No viable cells could be detected after 24 h of incubation.

CONCLUSIONThis study suggest that decapeptide might have potential clinical application in treating dental caries by killing S. mutans within dental plaque.