title: Synergistic effects and antibiofilm properties of chimeric peptides against multidrug-resistant Acinetobacter baumannii strains.
abstract: The increasing prevalence of drug-resistant pathogens highlights the need to identify novel antibiotics. Here we investigated the efficacies of four new antimicrobial peptides (AMPs) for potential drug development. The antibacterial activities, synergistic effects, and antibiofilm properties of the four chimeric AMPs were tested against Acinetobacter baumannii, an emerging Gram-negative, nosocomial, drug-resistant pathogen. Nineteen A. baumannii strains resistant to ampicillin, cefotaxime, ciprofloxacin, tobramycin, and erythromycin were isolated at a hospital from patients with cholelithiasis. All four peptides exhibited significant antibacterial effects (MIC=3.12 to 12.5 μM) against all 19 strains, whereas five commercial antibiotics showed little or no activity against the same pathogens. An exception was polymyxin, which was effective against all of the strains tested. Each of the peptides showed synergy against one or more strains when administered in combination with cefotaxime, ciprofloxacin, or erythromycin. The peptides also exhibited an ability to prevent biofilm formation, which was not seen with cefotaxime, ciprofloxacin, or erythromycin, though polymyxin also inhibited biofilm formation. Indeed, when administered in combination with ciprofloxacin, the AMP HPMA exerted a potent synergistic effect against A. baumannii biofilm formation. Collectively, our findings indicate that the AMPs tested have no cytotoxicity but possess potent antibacterial and antibiofilm activities and may act synergistically with commercial antibiotics.
authors.affiliation: Research Center for Proteinaceous Materials, Chosun University, Kwangju, Republic of Korea.
authors.forename: Ramamourthy
authors.initials: R
authors.lastname: Gopal
authors.forename: Young Gwon
authors.initials: YG
authors.lastname: Kim
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Seog Ki
authors.initials: SK
authors.lastname: Lee
authors.forename: Jeong Don
authors.initials: JD
authors.lastname: Chae
authors.forename: Byoung Kwan
authors.initials: BK
authors.lastname: Son
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Seo
authors.forename: Yoonkyung
authors.initials: Y
authors.lastname: Park
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy; D040981:Acinetobacter baumannii / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002439:Cefotaxime / Q000008:administration & dosage / Q000494:pharmacology; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D004357:Drug Synergism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000382:microbiology; D048628:Ketolides / Q000008:administration & dosage / Q000494:pharmacology; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D048628:Ketolides; D002939:Ciprofloxacin; D002439:Cefotaxime