Antimicrobial properties of Hyssopus officinalis extract against antibiotic-resistant bacteria in planktonic and biofilm form

Extensive use of antibiotics led to the development of bacterial resistant to antibiotics. Medicinal plants can be alternative choice for antibiotics. The plant (Hyssopus officinalis) belongs to Lamiaceae family recently were attracted as a source for antimicrobial agents. The aim of this study was to evaluate the antibacterial and inhibitory activity of H. officinalis extract on the growth of six antibiotic-resistant bacteria. In this study, ethanolic and methanolic extracts of H. officinalis were prepared. Antibacterial activity of the ethanolic and methanolic extracts was evaluated by paper disc diffusion method. Also, MIC and MBC of these extracts were determined for six pathogenic bacteria. The effect of these extracts on biofilm of bacteria (biofilm formation and destruction) was evaluated by microtiter plate method. The chemical composition of the extract was identified by GC-MS. The results of study showed the maximum inhibitory effect of these extracts against planktonic forms belong to Staphylococcus aureus and Pseudomonas aeruginosa. Between all studied bacteria, Acinetobacter baumannii showed the greatest sensitivity to H. officinalis extracts in Muller Hinton broth (MIC= 3.125 mg ml-1). The highest inhibitory effects of H. officinalis ethanolic extract on biofilm formation were observed against Escherichia coli (95 %). The results of biofilm destruction showed that Klebsiella pneumoniae biofilm had a resistant biofilm structure between all tested bacteria (16.41 %). The GC-MS analysis revealed that five active compounds were present in the extract of this plant. Discussion and conclusion: The data obtained in this study confirmed that H.officinalis extract inhibit growth and biofilm formation of some pathogenic bacteria. It can be proposed for future studies that the compounds of this plant used for design a antimicrobial agent.