title: Antimicrobial and anti-biofilm effect of Bac8c on major bacteria associated with dental caries and Streptococcus mutans biofilms.
abstract: Dental caries is a common oral bacterial infectious disease. Its prevention and treatment requires control of the causative pathogens within dental plaque, especially Streptococcus mutans (S. mutans). Antimicrobial peptides (AMPs), one of the promising substitutes for conventional antibiotics, have been widely tested and used for controlling bacterial infections. The present study focuses on evaluating the potential of the novel AMPs cyclic bactenecin and its derivatives against bacteria associated with dental caries. The results indicate that Bac8c displayed highest activity against the bacteria tested, whereas both cyclic and linear bactenecin had weak antimicrobial activity. The cytotoxicity assay showed that Bac8c did not cause detectable toxicity at concentrations of 32-128μg/ml for 5min or 32-64μg/ml for 60min. S. mutans and Lactobacillus fermenti treated with Bac8c showed variable effects on bacterial structure via scanning electron microscopy and transmission electron microscopy. There appeared to be a large amount of extracellular debris and obvious holes on the cell surface, as well as loss of cell wall and nucleoid condensation. The BioFlux system was employed to generate S. mutans biofilms under a controlled flow, which more closely resemble the formation process of natural biofilms. Bac8c remarkably reduced the viability of cells in biofilms formed in the BioFlux system. This phenomenon was further analyzed and verified by real-time PCR results of a significant suppression of the genes involved in S. mutans biofilm formation. Taken together, this study suggests that Bac8c has a potential clinical application in preventing and treating dental caries.
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of General Surgery, The 456th Hospital of PLA, Ji'nan City, Shandong, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Fan
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zhongchun
authors.initials: Z
authors.lastname: Tong
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Kuang
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: WenKai
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China. Electronic address: Longxing_Ni@hotmail.com.
authors.forename: Longxing
authors.initials: L
authors.lastname: Ni
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002478:Cells, Cultured; D003731:Dental Caries / Q000188:drug therapy* / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D013290:Streptococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013295:Streptococcus mutans / Q000502:physiology*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides
keywords: Antimicrobial peptides; Bac8c; Biofilms; Dental caries; Streptococcus mutans