Antimicrobial Efficacy Of Carrin 1.1 Peptide Against Streptococcus Mutans

This study aims to investigate the inhibitory effects of the caerin 1.1 peptide on Streptococcus mutans (S. mutans) and its biofilm, thereby offering novel insights for the prevention and treatment of clinical dental caries. The study evaluated the antibacterial effects of caerin 1.1 peptide against S. mutans using minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC), growth curves, and bactericidal kinetics. Membrane integrity was assessed via fluorescent staining, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyzed morphological changes. Biofilm formation was examined using crystal violet staining and phenol-sulfuric acid exopolysaccharide (EPS) quantification. The Methyl thiazolyl tetrazolium (MTT) assay measured biofilm destruction, and acid production/resistance tests assessed cariogenic virulence. Caerin 1.1 peptide exhibits strong antibacterial activity against S. mutans, with an MIC of 34 μM and MBC of 68 μM, disrupting membrane integrity and causing cell lysis, as confirmed by fluorescence staining, SEM, and TEM. It also inhibits biofilm formation and EPS synthesis in a dose-dependent manner (1/2MIC–2MIC) and effectively disrupts mature biofilms. Additionally, the peptide slows acid production, decreases acid tolerance (P < 0.05), and weakens S. mutans virulence, demonstrating broad antibiofilm and anticariogenic potential. Caerin 1.1 peptide can inhibit the growth of S. mutans and the formation of biofilm, destroy mature S. mutans biofilm, and reduce its acid production, acid resistance and EPS synthesis, thus weakening its cariogenic toxicity.