A quantitative assessment of the anti- microbial activity of garlic (A/hum sativum)

An aqueous extract of freeze-dried garlic (Allium sativum), when incorporated into growth media, inhibited many representative bacteria, yeasts, fungi and a virus. All microorganisms tested were susceptible to garlic. Quantitative assessment of the minimum inhibitory concentrations for bacteria and yeasts showed values ranging from 0.8 to 40.0 mg garlic ml-‘. Fungal radial colony growth was inhibited by at least 25% at concentrations as low as 2.0 mg garlic ml-‘. The 50% endpoint neutralization titre for rotavirus was 2.4 to 2.8 pg ml-‘. Lactic acid bacteria were the least sensitive microorganisms to the inhibitory effects of garlic. In mixed culture studies of Lactobacillus acidophilus and Escherichia co& garlic prevented the establishment of E. co& although the final outcome of competition was not affected.