EVALUATION OF THE RESISTANCE OF STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI REGARDING PLANT EXTRACTS ON MODELS OF PLANKTONIC CELLS AND BIOFILM

Abstract

The resistance of Staphylococcus aureus and Escherichia coli was assessed using two ecological models: planktonic cells and biofilms. As herbal preparations, 8 official medicinal plants with pronounced antibacterial and anti-inflammatory properties, purchased in the pharmacy network, produced by ZAO Krasnogorskleksredstva and collected in North Ossetia-Alania, were used. Antibiofilm activity was determined in common garlic (Allium sativum) and common thyme (Thymus vulgaris). Used pomace from the green mass of plants, alcohol tinctures. The severity of the antibacterial activity of the tested preparations was determined by the standardized Kerby-Bauer method. To create an artificial biofilm, the method of isolated biofilm and the method of culturing static biofilms in liquid were used; to assess the relative growth rates, staining with gen-cyan violet was carried out. The conducted studies (pomace from the green mass of plants) in relation to the culture of Staphylococcus aureus revealed either the absence of a zone of growth inhibition (Pinus sylvestris, Thuja occidentalis) or the presence of a low sensitivity of planktonic cells to the tested preparations. When using the dry mass of pharmaceutical preparations (alcohol tinctures), antibacterial activity against planktonic Staphylococcus aureus cells was detected in extracts of garlic and common thyme (high), coltsfoot and eucalyptus rod (sufficient). Escherichia coli strains were resistant to almost all tested drugs (no growth retardation or low sensitivity). Antibiofilm activity was manifested only at the growth stage (stable adhesion) when using extracts of garlic and common thyme in relation to Staphylococcus aureus and Escherichia coli.

Keywords

• plant extracts
• biofilms
• antibiotic resistance