In Vitro Determination of the Antibacterial Activity of AgNPs using Syzygium Aromaticum Against Streptococcus Mutans

Abstract

Objective: To evaluate the antimicrobial activity of AgNPs with clove extract against Streptococcus mutans and determine their MIC and MBC

Study Design: Controlled, in vitro laboratory experimental study
Place and Duration of Study: This study was conducted at the Department of Basic Sciences, College of Dentistry, Al-Qadisiyah University, Qadisiyah Governorate, Iraq, from 14th Jan 2025 to 20th September 2025.

Methodology: Biosynthesis of SA AgNPs and characterization using UV-Vis, FTIR, XRD, and SEM. The antibacterial activity was determined by the agar well diffusion method then estimate the MIC and MBC.

Results: The XRD pattern of the pure silver sample has a closely match JCPDS card No. 04-0783 with four sharp, visible diffraction peaks appeared at specific 2Ɵ angles. FTIR spectroscopy of SA AgNPs identified the specific
functional groups. High absorption of AgNPs appeared at 421nm in the UV-Vis spectrum. SEM analysis showed a crystalline nature and quasi-spherical form of AgNPs with dimensions 14 - 32 nm. The zones of inhibition for AgNPs synthesized using Syzygium aromaticum were determined using agar well diffusion method. SA AgNPs at a concentration of 20 mg/mL displayed the most potent antibacterial action, producing the largest zone of inhibition measuring 19 ± 0.8 mm. The inhibitory activity was initiated at 0.32 mg/ml, while the MBC was 1.25 mg/ml. The calculated MBC/MIC ratio was determined to be approximately 3.9 (∽4).

Conclusion: The results suggested that Ag nanoparticle synthesis with Syzygium aromaticum can be used as an effective inhibitor of bacterial growth.