Inhibitory Effect Of Some Plant Extracts On Selected Pathogenic Bacteria

ABSTRACT

The Antibacterial Activity Of The Ethanolic And Aqueous Extracts Of Piper Guineense, Xylopia Aethiopica And Garcinia Kola Against Eschericha  Pseudomonas Aeruginosa And Staphylococcus Aureus Were Evaluated Using The Impregnated Paper Disc And Agar-Well Diffusion Methods. The Growth Inhibitory Response Varied With Bacterial Strains Tested And The Type Of Extract. Ethanolic Extracts Of Garcinia Kola And Xylopia Aethiopica Produced A Marked Inliibitoiy Effect On Staphycococcus Aureus And Pseudornonas Aeruginosa (18.0mm — 21.0mm) And (17.0mm To 21.0mm) Respectively But Showed Little Or No Activity Against Escherichia Coil. The Aqueous Extract Of Piper Guineense Showed More Inhibitory Activity Than The Ethanol Extracts With Zone Diameter Of 24.0mm Against 14.4mm On Escherichia Coil, And 20.0mm Against 16.0mm On Pseudomonas Aeruginosa. The Agar-Well Detennined Minimum Inhibitory Concentration (Mic) Values For The Ethanolic And Aqueous Extracts Were Lower Indicating Higher Sensitivity Than The Corresponding Paper Disc Determined Values Probably Because Of Rapid Evaporation Of The Essential Oils From The Paper Disc. The Mic Values Of The Three Plant Extracts Were In The Range Of 0.5mg (12.5mg/Mi) To 4mg (100mg/Mi). These Results Indicated That The Aqueous And Ethanol Extracts Of These Plants Have Growth Inhibitory Effects In Vitro Against Specific Bacteria Suggesting Their Use In Folk Medicine.