Rapid systemic and local treatments with the antibacterial peptide dimer A3-APO and its monomeric metabolite eliminate bacteria and reduce inflammation in intradermal lesions infected with Propionibacterium acnes and meticillin-resistant Staphylococcus aureus.
When administered intramuscularly, the designer antibacterial peptide dimer A3-APO is highly efficacious in mouse models of Acinetobacter baumannii and Staphylococcus aureus burn infections. Here we compared the efficacy of A3-APO and its monomeric metabolite in mouse models of S. aureus and Propionibacterium acnes intradermal infections following administration as intramuscular (i.m.) or topical treatments. In the animal models, either (i) the ears of CD-1 mice were infected with P. acnes or (ii) S. aureus was injected into burn wounds inflicted to the back. A3-APO or the monomer were injected intramuscularly at 5 mg/kg one to three times or were applied three times as 1% local treatment in phosphate-buffered saline or Vaseline(®). Despite being inactive against the strains in vitro, in vivo the skin conditions of the mice were dramatically improved upon peptide treatment regardless of dosing frequency, administration mode or drug valency. In the P. acnes study, A3-APO statistically significantly reduced ear thickness and ear bacterial counts. The amount of ear connective tissue and epithelial macrophages correlated with therapeutic success. Bacterial load in the lesions was more representative of physical improvement than ear dimensions. In the S. aureus model, both peptides eliminated wound bacteria from >10(7) CFU/mg to almost background levels, with monomer treatment being somewhat more successful. In conclusion, A3-APO and its monomeric metabolite very efficiently ameliorate resistant aerobic and anaerobic intradermal infections, but the protection is apparently not due to direct bacterial killing. Immunostimulatory and anti-inflammatory actions are likely involved. Nevertheless, topical and i.m. administrations are equally effective.
Department of Dermatology, Venereology and Dermatooncology, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
Eszter
E
Ostorhazi
Elvira
E
Voros
Eva
E
Nemes-Nikodem
Dora
D
Pinter
Palma
P
Sillo
Balazs
B
Mayer
John D
JD
Wade
Laszlo
L
Otvos
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D058491:Bacterial Load; D004195:Disease Models, Animal; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D007273:Injections, Intramuscular; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D051379:Mice; D010455:Peptides / Q000008:administration & dosage*; D011425:Propionibacterium acnes / Q000187:drug effects* / Q000302:isolation & purification; D017192:Skin Diseases, Bacterial / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D016896:Treatment Outcome
C539766:A3-APO peptide; D000900:Anti-Bacterial Agents; D010455:Peptides
Acne vulgaris; Bacterial counts; Burn injury; Cream formulation; Immunostimulation