Screening of Natural Plant Extracts for Antimicrobial Activity Against Streptobacillus moniliformis

Abstract

The rise of antimicrobial resistance has driven the search for alternative antibacterial agents, including plant-based compounds. This study evaluates the antimicrobial potential of selected herbal extracts against Streptobacillus moniliformis using the agar well diffusion method. The tested extracts included Tulsi leaves (Ocimum sanctum), Neem leaves (Azadirachta indica), Bael leaves (Aegle marmelos), Adarak peels (Zingiber officinalef), Moringa seeds and leaves (Moringa oleifera), Dalchini (Cinnamomum verum), Lemon/Orange peels (Citrus limon and Citrus sinensis), and Ginger peels (Zingiber officinale). Among these, Bael leaves and Lemon peels demonstrated significant antibacterial activity, forming distinct zones of inhibition. In contrast, Neem and Moringa extracts did not inhibit bacterial growth. The observed antimicrobial activity is likely due to the presence of bioactive compounds such as flavonoids, tannins, and essential oils, which may disrupt bacterial cell walls and metabolic processes. Notably, S. moniliformis exhibited limited survival in culture, while other bacterial strains showed minimal resistance. These findings suggest that certain herbal extracts, particularly Bael leaves and Lemon peels, may serve as natural antimicrobial agents against S. moniliformis. Further studies are required to isolate and characterize the active compounds responsible for this antibacterial activity to explore their potential in developing alternative antimicrobial therapies.