title: Pleurocidin congeners demonstrate activity against Streptococcus and low toxicity on gingival fibroblasts.
abstract: OBJECTIVE
  Fish epidermal antimicrobial peptides, such as pleurocidin, are cathelicidins with broad-spectrum antimicrobial activity against gram negative and gram-positive bacteria, as well as fungi. In the current study, we attempted to optimize peptide bioactivity by sequence modification and assess the antimicrobial activities.
  
  
  METHODS
  Fifteen pleurocidin analogues were designed, and the efficacy of pleurocidin congeners against common cariogenic microorganisms was tested; furthermore, we performed a preliminary study of the antimicrobial mechanism. We assayed the minimal inhibitory concentration (MIC), minimal bactericide concentration (MBC) and bactericidal kinetics to determine the cell killing activity. Scanning electron microscopy (SEM) was used to observe the bacterial membrane after treatment with congeners' peptides. Human gingival fibroblasts (HGFs) were also used in toxicity studies.
  
  
  RESULTS
  The MIC and MBC results indicated that peptide congeners had different antimicrobial activities against the tested oral strains. Toxicity studies indicated that several congener peptides had little effect on human gingival fibroblasts (HGFs) with 5min of in vitro treatment.
  
  
  CONCLUSIONS
  Our findings suggested that several pleurocidin congeners had the antimicrobial effect against Streptococcus mutans, Streptococcus sanguinis and Streptococcus sobrinus.
authors.affiliation: Department of Stomatology, The 101 Military Hospital, Wuxi 214000, People's Republic of China.
authors.forename: Mengjie
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
authors.forename: Wang
authors.initials: W
authors.lastname: Wei
authors.affiliation: Department of Stomatology, The 101 Military Hospital, Wuxi 214000, People's Republic of China.
authors.forename: Yingming
authors.initials: Y
authors.lastname: Sun
authors.affiliation: School of Stomatology, Anhui Medical University, Anhui 230032, People's Republic of China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: School of Stomatology, Anhui Medical University, Anhui 230032, People's Republic of China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Ying
authors.affiliation: Department of Stomatology, The 101 Military Hospital, Wuxi 214000, People's Republic of China. Electronic address: taoruicn@outlook.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Tao
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
authors.forename: Longxing
authors.initials: L
authors.lastname: Ni
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D002942:Circular Dichroism / Q000379:methods; D005347:Fibroblasts / Q000187:drug effects*; D029941:Fish Proteins / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000633:toxicity; D005881:Gingiva / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013291:Streptococcus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D029941:Fish Proteins; C105851:pleurocidin
keywords: Antimicrobial peptides; Oral bacteria; Pleurocidin; Scanning electron microscopy