Antibacterial Activity of Gallic (Allium Sativum) Extracts on Food Borne Pathogens

The study was aimed to investigate the phytochemical constituents and antibacterial activity of Allium sativum extracts against some food borne pathogen. Aqueous and methanol extracts from Allium sativum bulbs were prepared, screened for phytochemical analysis and tested for antibacterial activity against 6 pathogenic bacteria (Klebsiella pneumoneae, Salmonella typhi, Shigella spp, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus). Phytochemical screening of the extracts showed that Allium sativum bulb extract contain Alkaloid, Anthraquinone, saponin, tannin, phenol, steroid, flavonoid, terpenoid, glycoside and reducing sugar. Alkaloid was found to be the most abundant constituent making about 7.2 %, followed by Tannin, saponin and flavonoid constituting 4.8 %, 4.3 % and 2.8 % respectively. Statistical analysis of the result showed that methanol extract demonstrated highest antibacterial activity with average zone of inhibition of 14.12±1.51 mm among the isolates than aqueous extracts (12.00±1.06 mm). Based on the susceptibility of the organisms to the extracts, E. coli was found to be the highest susceptible organisms with average zone of inhibition of 14.29±1.12 mm, followed S. aureus (13.61±1.23 mm), Salmonella typhi (13.56±1.89 mm), Shigella (13.22±1.41 mm), Pseudomonas (12.36 ±1.38mm) while least average zone of inhibition is shown by Klebsiella (11.33±0.80 mm). The MIC and MBC of the extracts ranges from 3.125 to 50 mg/ml There is no significant different on the susceptibility of the organisms against the extracts at p<0.05. The results of the present study have provided the justification for therapeutic potential of Allium sativum and also used as dietary supplement for food flavoring and preservation.

Keywords: Allium sativum; Pathogenic bacteria; Antibacterial activity; Phytochemicals