Antimicrobial and antibiofilm activity of certain South African plants against the oral pathogen - Streptococcus mutans

Abstract

Dental caries is a serious oral infection caused by microorganism in the oral cavity. Streptococcus mutans can colonize the teeth surfaces and forming biofilm leading to dental caries. The investigation of the antibacterial activity of the plants’ secondary metabolites may lead to the development of alternative therapeutics to treat multi-resistant bacterial infections. South Africa has unique floral biodiversity especially in the Cape region and many of these plants have been used locally for medicinal use. In this study, the antibacterial activities of several South African plant extracts have been tested against S. mutans in-vitro. Psoralea pinnata and Otholobium fruticans showed the highest antimicrobial activity with MIC value of 31.25 μg/mL against S. mutans. The same extracts also effectively inhibited the biofilm formation by S. mutans.