title: In vitro susceptibility of the Streptococcus milleri group to antimicrobial peptides.
abstract: OBJECTIVE
  To determine the susceptibility of strains of the Streptococcus milleri group (SMG) to commercially available antimicrobial peptides.
  
  
  METHODS
  Thirty strains of SMG from a range of sources were assessed for their susceptibility to 10 antimicrobial peptides of either human, animal or insect origin, using a double layer diffusion assay.
  
  
  RESULTS
  The majority of the test strains were sensitive to the amidated peptides, mastoparan (100%; n = 30), magainin 2 amide (95%; n = 21) and indolicin (91%; n = 23). Some strains were susceptible to cecropin B (30%; n = 30) and histatin (10%; n = 30), whilst no activity was observed for the defensins HNP-1 and HNP-2, histatin 8, cecropin P1 and magainin 2.
  
  
  CONCLUSIONS
  The majority of strains were resistant to the human derived peptides. The ability to resist such peptides may be a factor in the colonisation of the oral cavity and the survival and initiation of infection in the pulp and root canal environment. Interestingly, the present study indicated that amidated and alpha helical peptides exhibit antimicrobial activity against SMG. Structural modification of these peptides may allow a targeted approach for the development of these substances as preventative or therapeutic agents.
authors.affiliation: Department of Oral Microbiology, Leeds Dental Institute, Clarendon Way, University of Leeds, Leeds, UK.
authors.forename: K L
authors.initials: KL
authors.lastname: Bartie
authors.forename: D A
authors.initials: DA
authors.lastname: Devine
authors.forename: M J
authors.initials: MJ
authors.lastname: Wilson
authors.forename: M A O
authors.initials: MA
authors.lastname: Lewis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D054807:Cecropins / Q000494:pharmacology; D054808:Histatins / Q000494:pharmacology; D006801:Humans; D005779:Immunodiffusion; D007313:Insecta / Q000737:chemistry; D036341:Intercellular Signaling Peptides and Proteins; D054806:Magainins / Q000494:pharmacology; D008969:Molecular Sequence Data; D010455:Peptides / Q000494:pharmacology; D034364:Streptococcus milleri Group / Q000187:drug effects*; D014862:Wasp Venoms / Q000494:pharmacology; D023084:alpha-Defensins / Q000494:pharmacology
chemical_list: D023181:Antimicrobial Cationic Peptides; D054807:Cecropins; D054808:Histatins; D036341:Intercellular Signaling Peptides and Proteins; D054806:Magainins; D010455:Peptides; D014862:Wasp Venoms; D023084:alpha-Defensins; C406413:human neutrophil peptide 1; C406416:human neutrophil peptide 2; C073143:indolicidin; C037500:mastoparan