Analysis of Bactericidal and Bacteriostatic Effect of the Crude Extract of Scent Leaf (Ocimum gratissimum) on Escherichia coli and Staphylococcus aureus

Abstract

The antibacterial activity of the extract of Ocimum gratissimum was determined against Escherichia coli and Staphylococcus aureus. The phytochemical analysis of the leaf extract revealed the presence of bioactive bases responsible for antibacterial property, such as Saponin, Alkanoid, Flavonoid, Tanin and Steroid. The methanolic extraction of the active ingredient of the leaves was carried out using the method as described by Fatope, et al., (1993). The minimum inhibitory concentration (MIC) was 12.5mg/ml for E. coli and 25mg/ml for S. aureus and also had minimum bactericidal concentration of 6.25mg/ml for E. coli and 12.5mg/ml for S. aureus. The concentration 1.0mg/disc inhibited the isolates with highest diameter zone of inhibition as 15mm for E. coli and 13mm for S. aureus while the lowest diameter zone of inhibition as 8mm for E. coli and 7mm for S. aureus were recorded at concentration of 0.1mg/disc. Statistical analysis of the extract showed no significant difference (P> 0.05) the test isolates were sensitive to leaf extract of Ocimum gratissimum which implies that the leaf extract of Ocimum gratissimum can serve as a source of therapeutic agent and possess antibacterial properties.

Keywords- Ocimum gratissimum, Escherichia coli, Staphylococcus aureus Bactericidal, Bacteriostatic, Crude extract