Antimicrobial activity of SC5 and Bactenecin 3.4. from Capra aegagrus hircus

Abstract

The antimicrobial resistance problem has increased significantly over the last decades. As antibiotics has been a weapon against all kind of diseases since they were discovered, the overuse leaded to multiple resistances that slowly built an international problem where it takes much more dosage to fight illnesses. To minimise the risk of developing more resistance, several studies has been searching for new antimicrobial treatments that does not include antibiotics. In this study, we evaluated the antimicrobial activity of two goat’s cathelicidins, SC5 and Bactenecin 3.4 against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) strains. With this in view, both minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) were determined with the broth microdilution method using 48 strains of E. coli and 48 strains of S. aureus against goat’s peptides SC5 and Bac3.4. Susceptibility tests were also performed for all the strains. Comparing the results from both peptides, SC5 showed a greater and consistent antimicrobial activity than Bac3.4, specially against S. aureus. It is true that our results differ from other studies when it comes to Proline/Arginine-rich peptides (PAR-HDPs), the same kind as Bac3.4, but this may be due the strain variability, the methodology used and the structural modifications between peptides.