Effects of Essential Oils on Biofilm-Forming Microorganisms from Patients with Diabetic Foot

Our study was focused on the possibility of using essential oils (EOs) in the prevention of biofilm development by microorganisms isolated from patients with diabetic foot. Dominant microorganisms with a strong production of biofilms and effects of EOs on them are presented on the Table. Growth of biofilms was carried out in polystyrene microplates at 37°C for 24 hours. The EOs were extracted from following plants: Matricaria chamomilla (Asteraceae) (MCEO), Eucalyptus (Myrtaceae) (EEO), Tanacetum fruticulosum (Asteraceae) (TFEO), Thymus marschallianus (Labiatae) (TMEO) and Artemisia sieversiana (Asteraceae) (ASEO). Serial dilutions of EOs were prepared with dimethyl sulfoxide (1:1 v/v) and then in Mueller-Hinton broth with 0.5% Tween 20. The EOs were diluted to the following dilutions: 12.5%, 6.25%, 3.13%, 1.56%, 0.78%, 0.39%, 0,195%, 0,097%, 0,048%, and 0,024%. The EOs were deposited in wells of microplates with bacterial suspensions at 37°C for 24 hours and then we determined minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of EOs by OD (optical density) reading at a wave length of 600 nm. According to our study, strong effects of MCEO on gram-positive and gram-negative microbes were shown. The moderate effects were detected for other investigated EOs. Our results encourage research related to the application of essential oils to fight diabetic complications.