ANTIMICROBIAL ACTIVITY OF SOME PLANT EXTRACTS AGAINST THE BACTERIAL AND FUNGAL STRAINS

The increasing prevalence of drug-resistant pathogens underscores the need for alternative antimicrobial agents, particularly plant-derived phytochemicals. This study evaluated the antimicrobial potential of Soleirolia soleirolii, Arctium lappa (Burdock), and Psidium guajava using two extraction methods: decoction and percolation. Extraction yields varied, with decoction producing 25.0% (A. lappa) to 44.8% (P. guajava) and percolation yielding 33.2% to 49.7%, indicating improved recovery of thermolabile compounds in percolation. Antimicrobial activity was assessed in-vitro against Gram-positive (Bacillus cereus, Staphylococcus aureus), Gram-negative (Salmonella, Escherichia coli, Pseudomonas aeruginosa), and fungal (Candida albicans, Clostridia) strains. A. lappa showed broad-spectrum activity across both methods (zones: 8.5–11.0 mm), while P. guajava exhibited selective antibacterial effects, particularly against S. aureus and Salmonella, and strong antifungal activity against Clostridia. S. soleirolii displayed moderate, selective inhibition, with percolation enhancing activity against Salmonella. These findings highlight that extraction technique significantly influences yield and bioactivity. Overall, A. lappa is a promising natural antimicrobial, whereas P. guajava and S. soleirolii merit further bioassay-guided fractionation to identify active phytoconstituents for potential therapeutic applications against resistant pathogens.