Phytochemical Screening and Antibacterial Properties of Ethanol and Aqueous Extracts of Allium sativum (Garlic) on Staphylococcus aureus (ATCC 9144), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC BAA 1705)

The misuse of antibiotics has led to antibiotic resistance which is a major challenge in controlling of infectious diseases despite efforts towards discovery and production of new antibiotics. The search for novel antimicrobial agents to combat pathogens has become crucial. This study aimed at investigating antibacterial activity of ethanol and aqueous extracts of garlic (Allium sativum) against typed cultures of Staphylococcus aureus (ATCC 9144), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC BAA 1705). Qualitative phytochemical composition of the extracts were determined according to standard procedures, while agar well diffusion method was used for antibacterial assay. The results of phytochemicals revealed the presence of tannins, terpenes, flavonoids, anthraquinones, alkaloids, sterols, glycosides, while phenols and reducing sugars were absent. The two extracts at concentration of 20 mg/ml showed activity against the three clinical isolates with minimum inhibitory concentration (MIC) between 0.1325 mg/ml and 5 mg/ml and minimum bactericidal concentration (MBC) between 0.625 mg/ml and 10 mg/ml. Ciprofloxacin used as the standard drugs showed activity at 250 mg/ml. The findings therefore, has confirmed the use of garlic in treatment of infectious diseases in folklore.