Acacia nilotica: A Natural Antimicrobial Agent Compared to Standard Antibiotics

Abstract

This study evaluated the antibacterial efficacy of Acacia nilotica extracts against six bacterial strains: P. mirabilis, S. aureus ATCC 6538, E. faecium ATCC 14936, E. faecalis ATCC 29212, E. coli ATCC 8739, and Serratia spp. The extracts were tested in varying concentrations (1/10, 1/100, and 1/1000) and compared to standard antibiotics, including Amoxicillin, Cefotaxime, Amikacin, and Ciprofloxacin.

The results revealed that alcohol-based extracts exhibited superior antibacterial activity compared to aqueous extracts, with the hot alcohol extract at a (1/10) concentration showing the most significant effects. P. mirabilis and S. aureus were the most susceptible strains, demonstrating inhibition zones up to 30 mm with alcohol extracts. In contrast, Serratia spp. and E. coli were largely resistant across all extract types and concentrations. E. faecium and E. faecalis showed moderate sensitivity, particularly to hot alcohol extract. High-concentration extracts (1/10) consistently produced measurable inhibition zones, while diluted extracts (1/100 and 1/1000) showed reduced or no activity, highlighting the importance of extract concentration for antimicrobial efficacy. Cold alcohol extract showed the highest activity against S. aureus, while hot alcohol extract was most effective against P. mirabilis. When compared with antibiotics, Amoxicillin and Ciprofloxacin demonstrated the highest antibacterial activity, with inhibition zones reaching up to 48 mm against E. faecium.
A. nilotica extracts showed significant antibacterial activity, even against resistant strains, though they were less potent. The results emphasize A. nilotica's promise as a natural antibacterial, with its effectiveness influenced by the extraction method and concentration.