Molecular study of icaD biofilm gene expression by extract of ginger and artichoke in Staphylococcus aureus

Biofilm is an accumulation of bacteria that increase binding to biological and non-biological levels and causes pathogenicity and infection in Staphylococcus aureus. The icaABCD operon genes are involved. The icaD gene plays an important role in the maximal expression of the enzyme N-acetylglucosamine transferase and leads to the phenotypic expression of extracellular polysaccharide in S. aureus. In this study, based on antibiogram test, the antimicrobial effect of ginger and artichoke extract on two strains of S. aureus was studied. Also, in the studied strains, after the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests, using real time PCR technique, the expression of icaD biofilm gene under the treatment of artichoke and ginger extracts was evaluated. The results of disk diffusion test showed that the concentration of 100 mg/ml of ginger and artichoke extracts in the standard and the pathogen strains of Staphylococcus aureus, create a inhibition zone of 15 mm and about 9 mm, respectively. MIC test also showed that the studied strains can grow at a concentration of 5000 µg/ml of plant extracts. The results of icaD gene expression under the influence of artichoke and ginger extracts in the standard strain showed an increase in the expression of this gene. However, in the pathogen strain of Staphylococcus aureus, ginger and artichoke extracts led to a significant reduction (P