Promising Antimicrobial Activities of Essential Oils and Probiotic Strains on Chronic Wound Bacteria

Background: Disruption of the natural balance of the skin microbiota can impair wound healing and contribute to chronic infections. Identifying the bacterial species involved and understanding their antimicrobial susceptibility profiles are essential for guiding treatment, especially given the growing threat of antibiotic resistance. Methods: This study characterized the virulence and antibiotic resistance phenotypes of 43 bacterial strains isolated from chronic wounds. The antimicrobial activity of selected essential oils (sandalwood, ylang-ylang, sage, cajeput, and juniper), pharmaceutical products (propolis tinctures, usnic acid), and probiotic lactic acid bacteria strains (Lactobacillus spp., Lactococcus lactis) was assessed using qualitative and quantitative assays, including MIC, MICBA, and co-culture evaluations. Results: Gram-positive strains were more sensitive to essential oils than Gram-negative strains, with sandalwood, ylang-ylang, and propolis tincture showing the strongest antibacterial effects. These agents also showed significant biofilm inhibition. Probiotic strains exhibited antimicrobial activity against Staphylococcus aureus and Morganella morganii, with Lactobacillus paracasei and Lactobacillus rhamnosus being particularly effective in reducing bacterial growth and adhesion in vitro. Conclusions: Essential oils and probiotic strains demonstrate promising antimicrobial effects against chronic wound pathogens and may serve as alternative or adjunctive treatments to antibiotics. Further clinical research and standardization are necessary to establish their safety, efficacy, and optimal application protocols.