Evaluation of antibacterial activity and toxicity of enterocin P peptide and two essential oils against animal pathogens

Antibiotic resistance is one of the biggest threats to human and animal health. Antimicrobial peptides and herbal essentional oils are natural compounds that can act as an alternative to conventional antibiotics. In this study, Minimum Inhibitory Concentrations (MIC) was performed based on a microbroth dilution method by 96-well microtiter with four replicates with Cynara scolymus and Rosmarinus officinalis essential oils as well as Enterocin P peptide on animal pathogens as listed as Pseudomonas aeruginosa, Escherichia coli and Streptococcus agalactiae. After MIC, Bacterial species were cultured and minimum bactericidal concentration (MBC) was evaluated as that showing no growth. The toxicity of this peptide on normal cells was evaluated by MTT assay. The results showed that the lowest amount of MIC and MBC against all three bacteria belonged to Enterocin P peptide. The lowest amount of MIC (12.06 µg / mL) was reported on Pseudomonas aeruginosa and Streptococcus agalactiae by peptide and the highest amount of MIC (500 µg / mL) was showed on Pseudomonas aeruginosa by Cynara scolymus essential oil. The lowest value of MBC (12.06 µg / mL) on Streptococcus agalactiae was also observed by peptide. In addition, the results of the MTT assay showed that the peptide was not toxic to normal cells. Finally, as considering strong antibacterial effect and non toxicity of Enterocin P, it could be represent an alternative to classical antibiotics to control and fight bacterial infections in animal industry.