title: Evaluation of short synthetic antimicrobial peptides for treatment of drug-resistant and intracellular Staphylococcus aureus.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) infections present a serious challenge because of the emergence of resistance to numerous conventional antibiotics. Due to their unique mode of action, antimicrobial peptides are novel alternatives to traditional antibiotics for tackling the issue of bacterial multidrug resistance. Herein, we investigated the antibacterial activity of two short novel peptides (WR12, a 12 residue peptide composed exclusively of arginine and tryptophan, and D-IK8, an eight residue β-sheet peptide) against multidrug resistant staphylococci. In vitro, both peptides exhibited good antibacterial activity against MRSA, vancomycin-resistant S. aureus, linezolid-resistant S. aureus, and methicillin-resistant S. epidermidis. WR12 and D-IK8 were able to eradicate persisters, MRSA in stationary growth phase, and showed significant clearance of intracellular MRSA in comparison to both vancomycin and linezolid. In vivo, topical WR12 and D-IK8 significantly reduced both the bacterial load and the levels of the pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in MRSA-infected skin lesions. Moreover, both peptides disrupted established in vitro biofilms of S. aureus and S. epidermidis significantly more so than traditional antimicrobials tested. Taken together, these results support the potential of WR12 and D-IK8 to be used as a topical antimicrobial agent for the treatment of staphylococcal skin infections.
authors.affiliation: Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Mohamed
authors.affiliation: Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Abdelkhalek
authors.affiliation: Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.|Purdue Institute for Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Mohamed N
authors.initials: MN
authors.lastname: Seleem
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000254:growth & development*; D013207:Staphylococcal Skin Infections / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D013212:Staphylococcus epidermidis / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides