Screening of some plants from Northern Argentina for their antimicrobial activity

SALVAT, A.; ANTONACCCI, L.; FORTUNATO, R. H.; SUAREZ, E.Y.; GODOY, H.M.

LETTERS IN APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2001 vol. 32 p. 293 - 297

0266-8254

Inhibition of microbial growth was measured by a microplate assay with an oxidation±reduction indicator (Alamar Blue). Test organisms were: Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecium. Weak inhibitory activities (MIC . 0á5 mg dry matter ml)1) were found in methanolic extracts of Rivina humilis, Crateva tapia, Funastrum claucum and Schinopsisbalansae. Stronger bacteriostatic power was detected in Vassobia brevi¯ora (MIC . 0á25 mg ml)1 against Staphylococcus aureus, and 0á5 mg ml)1 against Enterococcus faecium). This activity was puri®ed ®ve-fold by extraction with dichloromethane, and it was found equally effective against susceptible or antibiotic-resistant strains of Staph. aureus. In addition, the puri®ed extract wassynergistic with gentamicin, and it was bactericidal at 24 h, with a concentration of0á25 mg ml)1.