The synergism effect of aqueous garlic extract and ciprofloxacin against some multi-resistant bacteria

Abstract

This study was aimed to evaluate the inhibitory effect of aqueous garlic extract (AGE) and synergism with two antibiotics Ciprofloxacin (CIP) and Ampicillin (Am) against 12 multi-resistant isolates, including two isolates of Staphylococcus aureus, three isolates of Pseudomonas aeruginosa and seven isolates of E. coli. Antibacterial activity of AGE was measured by using agar-well diffusion method at different concentration (200, 100, 50, 25 mg/ml). The results showed variable effect against the bacterial isolates, the highest inhibitory effect was seen against E.coli7 and Staphylococcus aureus2 as it reached to 25mm when 200 mg/ml concentration was used and the least effect was 8mm found against E.coli5by using the concentration 100 mg/ml. On the other hand the AGE did not show any inhibitory effect against Pseudomonas aeruginosa isolates. The synergism effect of the AGE and two antibiotics CIP & Am was studied by using double disc diffusion method. The results showed there is no any synergism between Am and the garlic extracts, while the CIP with garlic extract showed synergism effect in some bacterial isolates. E. coli(1,3,5,6,7) isolates showed synergism effect with inhibition zone ranged from (40-45),while the isolates 2 and 4 were resistant to the AGE ,but it's enhanced the inhibitory effect of the ciprofloxacin without any antagonism effect. The Same thing was seen with pseudomonas aeruginosa isolates. Finally the effect on the Staphylococcus aureus was additive which means the effect of the AGE and the CIP was equal to the summation of their effect together. Key words: aqueous garlic extract, garlic & ciprofloxacin synergism, Bacterial resistance