Antibacterial activity of ethanolic and aqueous extract of Acacia aroma Gill ex Hook et

ARIAS, M.E.; GÓMEZ, J.D.; VATTUONE, M.A.; ISLA,M.I.

LIFE SCIENCES

Elsevier

Lugar: Europa; Año: 2004 vol. 75 p. 191 - 202

0024-3205

ABSTRACT The purpose of the present study was to investigate the antibacterial activity of seven ethanolic extracts and three aqueous extracts from various parts (leaves, stems and flowers) of A. aroma against 163 strains of  antibiotic multi-resistant bacteria. The disc diffusion assay was performed to evaluate antibacterial activity of the A. aroma crude extracts, against several Gram-positive bacteria (E. faecalis, S. aureus, coagulase-negative stahylococci, S. pyogenes, S. agalactiae, S. aureus ATCC 29213, E. faecalis ATCC 29212) and Gram-negative bacteria (E. coli., K. pneumoniae, P. mirabilis, E. cloacae,  S. marcescens, M morganii, A. baumannii, P. aeruginosa, S. maltophilia, E .coli ATCC  35218, P. aeuruginosa ATCC  27853, E. coli ATCC  25922). All ethanolic extracts showed activity against gram-positive bacteria. Among all obtained extracts, only leaf and flower fluid extracts showed activity against Gram-negative bacteria. Based on this bioassay, leaf fluid extracts tended to be the most potent, followed by flower fluid extracts. Minimal inhibitory concentration (MIC) values of extracts and antibiotics were comparatively determined by agar and broth dilution method. Both extracts were active against S. aureus, coagulase-negative stahylococci, E. faecalis and E. faecium and all tested Gram-negative bacteria with MIC values from 0.125 to 0.250 mg/l. In this study the minimal bactericidal concentration (MBC) values were identical or two fold higher than the corresponding MIC for leaf extracts and four or eight times higher than MIC values for flower extracts. This may indicate a bactericidal effect. Stored extracts have similar antibacterial activity as recently obtained extracts. The A. aroma extracts of leaves and flowers may be useful as antibacterial agents against Gram- negative and Gram-positive antibiotic multi-resistant microorganism. Key words: Acacia aroma, antimicrobial activity, tusca, Gram-negative bacteria, Gram-positive bacteria, antibiotic-resistant.