Antibacterial potency of methanol extracts of lower plants.

Antibacterial potency of methanol extracts of three green lower plants, Pneumatopteris afra, Platycerium bifurcatum and Nephrolepsis bisserata was determined using agar dilution method on clinical strains of Escherichia coli, Staphylococcus aureus, Klebsiella spp. and Salmomelia typhi. Antibacterial activities were observed at concentrations of 12.5, 25.0, 50.0 and 100.0 microg/ml. Their minimum inhibitory concentrations ranged from 12.5approximately 100 microg/ml. Extracts of P. afra and P. bifurcatum were most active. Antibacterial activities observed with N. bisserata were less pronounced with no detectable activity at extract concentrations of 12.5 and 25.0 microg/ml. E. coli, together with S. aureus appeared to be the most susceptible of the test bacteria while Klebsiella spp. was least sensitive. The significance of our findings is discussed.