Abstract

INVITRO ANTIMICROBIAL AND ANTIBIOFILM ACTIVITY OF CLOVE (SYZYGIUM AROMATICUM) EXTRACT AGAINST METHICILLIN -RESISTANT (MRSA) AND METHICILLIN-SUSCEPTIBLE (MSSA) STAPHYLOCOCCUS AUREUS STRAINS

*Ms. S. Dharani Priya, Mrs. M. Indumathi, Ms. J. Ishwarya

ABSTRACT

The increasing prevalence of antibiotic-resistant pathogens, particularly Methicillin-resistant Staphylococcus aureus (MRSA), has necessitated the exploration of alternative antimicrobial agents. This study aimed to evaluate the in vitro antimicrobial and antibiofilm activity of clove (Syzygium aromaticum) extract against MRSA, Methicillin-susceptible Staphylococcus aureus (MSSA), and Staphylococcus aureus (control strain). Clove extract was prepared using methanolic extraction. Preliminary identification of isolates was performed using culture on MacConkey agar, Mannitol Salt Agar, Blood agar, and Nutrient agar. Confirmation was done using biochemical tests such as catalase, oxidase, and coagulase. Antibiotic susceptibility testing (AST) was conducted to determine resistance patterns and to differentiate MRSA and MSSA strains. The biofilm-forming ability of the isolates was assessed prior to treatment. Antimicrobial activity of the clove extract was evaluated using the agar well diffusion method, and the Minimum Inhibitory Concentration (MIC) was determinedat different concentrations. Antibiofilm activity was analysed to evaluate the inhibitory effect of the extract on biofilm formation. The results demonstrated that methanolic clove extract exhibited significant antimicrobial activity against all tested strains. MRSA isolates showed stronger biofilm-forming ability compared to MSSA. The extract effectively inhibited both bacterial growth and biofilm formation in a concentration-dependent manner. These findings suggest that clove extract has potential as a natural antimicrobial and antibiofilm agent against resistant Staphylococcus aureus infections.

Keywords: Staphylococcus aureus, MRSA, MSSA, clove extract, antimicrobial activity, antibiofilm activity.