IN VITRO DETERMINATION OF ANTIBACTERIAL EFFECT OF GARLIC ON SELECTED BACTERIAL ISOLATES

ABSTRACT

This study was carried out to determine the antibacterial activity of garlic purchased from a local market in Benin City against clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa. The disc diffusion method was used for assessing the antibacterial effect of garlic using two different extraction methods namely; soxhlet and cold extraction. The antibiotic susceptibility patterns   of these isolates were also assessed using the disc diffusion method. The Pseudomonas aeruginosa isolates were most sensitive to ciprofloxacin,septrin,ceporex and ofloxacin with 80% susceptibility.They were also most resistant to augumentin,nalidixic acid and pefloxacin with 20% susceptibility. Staphylococcus aureus was   most sensitive to   cephalexin with 60% susceptibility. They were also most resistant to amoxicillin, rifampin,erythromycin and ampiclox showing no zone of inhibition,hence resistant. Zones of inhibition produced by the cold extract against Staphylococcus aureus   ranged from 10mm to 16mm in diameter while no zone of inhibition was recorded from the soxhlet extract. Pseudomonas aeruginosa showed sensitivity ranging from 8mm to 10mm in diameter for the cold extract while it ranged from no activity to 15mm from the soxhlet extract. Sensitivity of each bacterial isolate varied and some did not show any zone of inhibition from the soxhlet extract. However, the cold extract appeared more effective than the soxhlet extract. More research needs to be done on why some strains of these same organisms are susceptible to garlic extract and others are not.