EVALUATION OF THE ANTIMICROBIAL ACTIVITY OF FRESH EXTRACTS OF ALLIUM SATIVUM AND ITS INTERACTION WITH SOME ANTIBIOTICS

ABSTRACT

The objective of this study was to evaluate the antimicrobial activity of fresh extracts of Allium sativum against a wide range of clinical fungal and bacterial isolates and its interaction with some standard antimicrobial agents.

The minimum fungistatic concentration and the minimum fungicidal concentration against the three clinical isolates, Aspergillus niger, Trichophyton mentagrophyte var interdigitale and Microsporium audouinii as well as the minimum inhibitory concentration and minimum bactericidal concentration against three clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were evaluated using the macrobroth dilution method. The minimum inhibitory concentration of fresh extracts of Allium sativum against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were 12.50 mg/ml, 25.00 mg/ml and 6.25 mg/ml respectively. While its minimum bactericidal concentration against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were 25.00 mg/ml, 50.00 mg/ml and 12.50 mg/ml respectively.

Furthermore, the minimum fungistatic concentration of fresh extracts of Allium sativum against Trichophyton mentagrophyte was 12.50 mg/ml. Aspergillus niger and Microsporium audouinii had similar MICs of 25.00 mg/ml while the minimum fungicidal concentration of the garlic extracts against Aspergillus niger, Trichophyton mentagrophyte var interdigitale and Microsporium audouinii were 12.50 mg/ml, 25.00 mg/ml and 50.00 mg/ml respectively.

Interaction studies, between Allium sativum and miconazole against the clinical fungal isolates on one hand and Allium sativum and chloramphenicol against the clinical bacterial isolates on the other hand using the strip-agar diffusion method, were carried out. The checkerboard technique was also employed to further evaluate the interaction between Allium sativum and chloramphenicol against the clinical bacterial isolates. From the results obtained using the strip-agar diffusion method, the combination of Allium sativum and miconazole against the clinical fungal isolates showed some level of synergism while the combination of Allium sativum and chloramphenicol against the clinical bacterial isolates exhibited antagonism.