title: Comparative in vitro activity of five cathelicidin-derived synthetic peptides against Leptospira, Borrelia and Treponema pallidum.
abstract: OBJECTIVE
  The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of five different cathelicidin-derived synthetic peptides (SMAP-29, LL-37, PG-1, CRAMP and BMAP-28) for Leptospira interrogans, Borrelia spp. and Treponema pallidum subsp. pallidum were investigated in vitro.
  
  
  METHODS
  The MIC of individual peptides was defined as the lowest concentration able to inhibit the motility of spirochaetes after 2 h of incubation, as detected by dark-field microscopy. The MBC of individual peptides was defined as the lowest concentration at which no spirochaetes were subcultured either in cathelicidin-free medium (leptospires and borreliae) or in hamsters (T. pallidum).
  
  
  RESULTS
  The MIC values of peptides for leptospires were highly variable, depending on the compound and the strain used. Of the five cathelicidin-derived peptides, SMAP-29 from sheep and BMAP-28 from cattle were the most active against L. interrogans serovars, with MIC values varying between 3 and 51 mg/L, depending on the strains. The MICs of the remaining synthetic peptides ranged between 4.3 and 224 mg/L. The MIC values of synthetic peptides for T. pallidum ranged between 32.3 mg/L for PG-1 and 449.4 mg/L for LL-37. The MICs of all cathelicidin-derived peptides tested for Borrelia strains ranged between 307 and 449.4 mg/L. The activity of the peptides on the motility of spirochaetes was both dose- and time-dependent. The MBC values of the peptides were the same as the MIC values.
  
  
  CONCLUSIONS
  The results of this study demonstrate that the activity of cathelicidin-derived peptides against spirochaetes is fast and highly variable, depending on the species and the strain.
authors.affiliation: Sezione di Microbiologia, DMCSS, Ospedale Policlinico S.Orsola, University of Bologna, Via Massarenti 9, 40138 Bologna.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Sambri
authors.forename: Antonella
authors.initials: A
authors.lastname: Marangoni
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Giacani
authors.forename: Renato
authors.initials: R
authors.lastname: Gennaro
authors.forename: Rossella
authors.initials: R
authors.lastname: Murgia
authors.forename: Roberto
authors.initials: R
authors.lastname: Cevenini
authors.forename: Marina
authors.initials: M
authors.lastname: Cinco
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001798:Blood Proteins / Q000494:pharmacology; D001898:Borrelia / Q000187:drug effects* / Q000302:isolation & purification; D054804:Cathelicidins; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D006224:Cricetinae; D006801:Humans; D007919:Leptospira / Q000187:drug effects* / Q000302:isolation & purification; D008297:Male; D008647:Mesocricetus; D051379:Mice; D008826:Microbial Sensitivity Tests / Q000706:statistics & numerical data; D011506:Proteins / Q000494:pharmacology; D011817:Rabbits; D012756:Sheep; D013552:Swine; D014210:Treponema pallidum / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; C102360:BMAP-28; D001798:Blood Proteins; D054804:Cathelicidins; D011506:Proteins; C403305:SMAP29 protein, Ovis aries; C094880:protegrin-1