Screening of antibacterial activity of south Brazilian Baccharis species

Abstract

South Brazilian Baccharis species were studied for antibacterial activities against Gram-positive and Gram-negative bacteria using disk diffusion and broth dilution assays. The results showed that the n-BuOH fraction (100 μg) from Baccharis usterii Heering exhibited inhibitory activity against Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium. The n-BuOH fraction of Baccharis spicata (Lam.) Bailon (100 μg) was effective against S. aureus, Escherichia coli, Enterococcus faecalis, and Enterococcus faecium. The crude extract of Baccharis trimera (Less) A. P. de Candolle (in doses of 1000 μ/disc) showed activity against S. aureus. The minimum bactericidal concentration (MBC) obtained from n-BuOH fraction of B. spicata were 50 mg/ml against S. aureus, E. coli, E. faecalis, and E. faecium. From the crude extract of B. trimera, a MBC of 25 mg/ml was obtained against S1. aureus. The n-BuOH fraction of B. usterii showed a MBC of 25 mg/ml against S. aureus and 50 mg/ml against E. faecalis and E. faecium, while the crude extract of this plant showed a MBC of 12.5 mg/ml against S. aureus. © 2005 Taylor & Francis Ltd.