Antibacterial activity of antimicrobial peptides nisin and melittin and essential oils on bacteria causing skin infections

Abstract

Resistance to antibacterial drugs has increased, showing the need and urgency of research aimed at new therapeutic options in the treatment of infectious diseases. Among these diseases, those that occur on human skin (pyoderma) represent a very important spectrum. Thus, natural products such as essential oils and antimicrobial peptides have been studied to try to alleviate this problem that is worldwide. Thus, this study aims to expand knowledge on the potential use of two essential oils (Eugenia uniflora-Pitanga, Copaifera reticulata-Copaíba) and Copaifera reticulata oil resin and two antimicrobial peptides (nisin, a bacteriocin produced by Lactococcus sp, and melittin, a protein fraction in the composition of the venom of bees of the species Apis mellifera. In this way, we will quantify the inhibitory potential of these antimicrobials and the inhibitory potential of these antimicrobials against ATCC strains of methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes and Cutibacterium acnes bacteria by the microdilution methodology (REMA - Resazurin Microtiter Assay) and obtaining the minimum inhibitory concentration (MIC). The choice of bacteria occurred because they are important causes of human skin infections. In addition to the MIC tests for the bacteria studied, tests will also be performed using the antimicrobial product with the best inhibitory effect on the bacteria tested in order to demonstrate anti-biofilm and bacterial plasma membrane actions and synergism with conventionally used antibacterial drugs. Finally, the cytotoxicity of this product on non-tumor keratinocytes (HaCat strain) will also be verified using flow cytometry metodology. Therefore, with this research, we intend to contribute to the knowledge of the action mechanisms from natural antimicrobial compounds and demonstrate their potential in the treatment of human skin infections caused by these microorganisms.