THE ANTIBACTERIAL ACTIVITY OF THE AQUEOUS EXTRACT OF SIDA ACUTA BURM. F.

摘要

Increasing bacterial resistance to antimicrobial drugs had led to the search for new antibacterial agents. A Thai medicinal plant, Sida acuta Burm. F. (SA), has been used for wound healing. The objective of this study was to determine the antibacterial activity of the aqueous extract of SA (SA-AE) against the antimicrobial-susceptible strains including three gram-positive bacteria: Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923 and S. aureus ATCC 29213; and four gram-negative bacteria: Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Proteus mirabilis DMST 8212 and Pseudomonas aeruginosa ATCC 27853, using the disc diffusion and broth microdilution methods. We also conducted high performance liquid chromatography (HPLC) profile on SA-AE to determine the major components. The results of disc diffusion test of SA-AE at 5 mg/disc showed no inhibition zone for all these strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for S. aureus ATCC 25923 and S. aureus ATCC 29213 were 16 mg/ml and 16 mg/ml, respectively, which were lower than MIC and MBC values of SA-AE for the other strains. HPLC reveals SA-AE contains para-hydroxybenzoic acid, ferulic acid and resveratrol. SA-AE should be explored further as an antimicrobial agent against S. aureus.