Abstract

Escherichia coli is known to produce enterotoxins whose properties and roles in diarrheal disease have been extensively investigated. Some species of Staphylococcus are often recognized as etiological agents of many animal and human opportunistic infections. This study is the first test of change in the resistance of antibiotic activity by Ocimum gratissimum L. against multi-resistant strains of E. coli and Staphylococcus aureus. In this study, the hexane and methanol extracts of O. gratissimum L. were tested for antibacterial activity alone and in combination with aminoglycosides against bacterial strains. The synergy of the methanolic extracts was verified by micro dilution method. A synergistic effect of both extracts and fractions combined with the aminoglycosides was demonstrated. It is therefore suggested that the extracts from O. gratissimum L. could be used as a source of natural products derived from this plant with resistance-modifying antibacterial activity, providing a new weapon against the problem of bacterial resistance to antibiotics.

Key words: Ocimum gratissimum L., methanol extract, fractions, antibacterial activity, modification of resistance, antibiotics, Staphylococcus aureus, Escherichia coli.