Evaluation of Short Synthetic Antimicrobial Peptides against Staphylococcus pseudintermedius

Staphylococcus pseudintermedius infections present a serious challenge because of the emergence of resistance to numerous conventional antibiotics. Antimicrobial peptides are novel alternatives to traditional antibiotics due to their unique mechanism of action. In this study, we investigated the antibacterial activity of 12 short synthetic peptides against two clinical isolates of S. pseudintermedius isolated from two dog cases with ophthalmic lesions. In addition, the ability of the peptides to disrupt the established biofilm of these two S. pseudintermedius isolates was investigated. RRIKA and 5RHH showed good antimicrobial activity with MICs 2 and 4 µg/ml, respectively. IK8aIID and Indolicidin showed antimicrobial activity with MICs 8 and 16 µg/ml, respectively. Indolicidin, 5RHH and IK8aIID showed a significant biofilm mass % reduction up to 90%.  Taken together, these results support the potential use of antimicrobial peptides for the treatment of S. pseudintermedius infections.