Hamadan University of Medical Sciences Avicenna Journal of Clinical Microbiology and Infection 2383-0298 10 4 2023 12 29 The Antimicrobial Activity of Propolis Ethanolic Extract and Silver Nanoparticles Synthesized by Green Method on Gram-Positive and Negative Bacteria 131 136 10.34172/ajcmi.3514 EN Zahra Karimitabar https://orcid.org/0009-0009-7170-5271 Abbas Farmani Masoud Azimzadeh Mohammad Sina Alikhani Masoud Moghadam Shakib Mohammad Yousef Alikhani https://orcid.org/0000-0003-4577-4029 Journal Article 10.34172/ajcmi.3514 2023 11 23 2023 12 19 Background: The increasing resistance of bacteria to different classes of antibiotics has become an important public health concern. This study was aimed at the effectiveness of the antibacterial effect of silver nanoparticles and propolis (AgNPs@propolis) on bacteria. Methods: A hydroalcoholic extract of propolis was used for prepare of silver nanoparticles (AgNPs@propolis). The characteristics, anti-bacterial effect and cell toxicity of AgNPs@propolis were examined in vitro. Results: The size of the synthesized nanoparticles was 32 to 85 nm. The AgNPs@propolis had no toxic effect up to a concentration of 200 μg/mL. Compared to AgNPs and propolis, AgNPs@ propolis showed a greater inhibitory effect on the growth of gram-positive and gram-negative bacteria. propolis as a natural substance has an inhibitory effect on the growth of bacteria. Conclusion: Green synthesis of AgNPs@propolis has a low toxic effect on the cell and has a high effect in inhibiting the growth of various bacteria.