ANTI-BIOFILM ACTIVITY OF CYNANCHUM ACUTUM LEAVES EXTRACT AND ASSESSING THEIR EFFECT AGAINST THE VIRULENCE GENE SEG OF STAPHYLOCOCCUS AUREUS BACTERIA

Abstract

Due to the ability of bacteria to develop many mechanisms of resistance to multiple drugs and antibiotics, and the emergence of strains with acquired resistance through horizontal transfer, and due to the excessive or underuse of antibiotics, and their spread in all countries of the world. This study aimed to evaluate the effect of the ethanolic extract of  Cynanchum acutum leaves as an anti-biofilm formation agent and to study the gene expression of the virulence gene SEG that contributes to the production of enterotoxins in resistant Staphylococcus aureus bacteria after treatment. Methods: The disk diffusion method was used to determine the extent of bacteria's resistance to 12 antibiotics. A 96-well microtiter plate and ELISA technology were also used to verify the ability of bacteria to form biofilms, as well as the ability of the ethanolic extract to inhibit their formation. RNA treated with ethanolic extract was extracted using the triazole method to study its effect on gene expression of the virulence gene SEG. Results: The results showed that all isolates produced biofilms that ranged from very to moderately strong with high to moderate adhesion. The concentrations of the extract in inhibiting biofilms ranged between 62,500 - 31,200 µg/ml. Gene expression results after treatment showed a significant increase in the virulence gene, with the exception of one isolate with down regulation. Conclusions: The results revealed that there is an inverse relationship between inhibitory activity and gene expression after treatment with the extract, as it has inhibitory activity on biofilms and is considered a stimulator of a gene that contributes to the production of intestinal toxins.

Keywords: Cynanchum acutum, Staphylococcus aureus, Antibiotic,  anti-biofilm activity,and Gene expression