Antibacterial activity of a complex bacteriocin secreted by Staphylococcus epidermidis against Porphyromonas gingivalis

Objective: To characterize the inhibitory activity of a novel bacteriocin produced by Staphylococcus epidermidis against this periodontal pathogen.Design: The bacteriocin activity was evaluated by the agar diffusion method over a lawn of P. gingivalis ATCC 33277. The bacteriocin was purified by Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) and Matrix Assisted Laser Desorption Ionization -Time of Flight Mass Spectrometry (MALDI-TOF-MS). In addition, the bacteriocin host specificity, production on different media cultures and susceptibility to enzymes, pH, and heat treatment were determined.Results: The bacteriocin BAC 14990 was selective to P. gingivalis, suggesting a narrow activity range. The production during the growth curve indicated that S. epidermidis had a continued production of this antimicrobial, showing the highest concentration in the stationary phase. The purification of BAC 14990 showed that bacteriocin had a molecular mass of 5795 Da. BAC 14990 was partially resistant to the treatment with proteinase K and papain, however, was fully susceptible to amylase treatment indicating the presence of sugar residues in the protein, suggesting a conjugated type of bacteriocin. Also, this diffusible inhibitory substance was heat and pH treatment resistant.Conclusions: The results indicate the isolation of a new staphylococcal complex bacteriocin that is able to eliminate a Gram-negative bacterium. These results could contribute to the development of treatments directed against pathogens in mixed communities, as is the case with oral diseases.

Automated summary

This study aimed to characterize a novel bacteriocin produced by Staphylococcus epidermidis that exhibits inhibitory activity against the periodontal pathogen Porphyromonas gingivalis. The bacteriocin was evaluated for its activity, specificity, production, and susceptibility to various treatments. The results suggest the isolation of a new staphylococcal complex bacteriocin that can eliminate a Gram-negative bacterium, which could be promising for the development of treatments against oral diseases caused by mixed bacterial communities.