Photodynamic Activation using Herbal Extract and Low-Power Laser against Gram-Positive (Streptococcus mutans) and Gram-Negative (Klebsiella pneumoniae) Bacteria: Threats and Resistance Mechanisms

Authors

• Zahra AghaEbrahimi ¹
• Jamshid Sabaghzadeh * ¹
• Sasan Soudi ²
• MohamadReza Tanhayi Ahari ¹

1. Department of Physics, Central Tehran Branch, Islamic Azad University, Tehran, Iran
2. Department of Medical Engineering, Faculty of Health and Medical Engineering, Tehran Medical Sciences

Abstract

This paper investigates the efficacy of photodynamic activation (PDA) using herbal extract in combination with low-power laser treatment against both Gram-positive (Streptococcus mutans) and Gram-negative (Klebsiella pneumoniae) bacteria. The study explores the threats posed by these bacteria and highlights their resistance mechanisms. Various experiments, including colony formation assays, minimal inhibitory concentration tests, and bacterial viability assays, were conducted to assess the antibacterial effects of PDA in the presence and absence of laser irradiation. Additionally, spectroscopic analysis of the herbal extract was performed to elucidate their composition and potential synergistic interactions with PDA.

Keywords

• Photodynamic activation
• Herbal extract
• Low-power laser
• Antibacterial effects
• Resistance mechanisms