The present study has shown that certain plant extracts and select fractions and standard chemical compounds exhibit antimicrobial effects. Prince's Pine, Chimaphila umbellate, White Birch, Betula papyrifera, Staghorn Sumac, Rhus typhina, and Green Ash, Fraxinus pennsylvanica were the principal extracts exhibiting notable antibacterial and/or antifungal activities; while gallic acid, ethyl gallate, and caffeic acid demonstrated antibacterial activities and sinapic acid, gentisic acid, and chlorogenic acid demonstrated antifungal activities.