Antibacterial efficacy of raw and commercially available honey

In vitro antibacterial activity of raw and commercially available honey was tested against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella spp. and Salmonella spp.). Both types of honey showed antibacterial activity against test organisms with the zone of inhibition ranging from 8.13 to 30.85 mm, while E. coli, S. aureus, and Shigella spp. showed sensibility towards both types of honey. Raw honey possesses more inhibitory activity against S. aureus and Shigella spp., than commercially available honey. On the other hand, commercially available honey possesses more inhibitory activity than raw honey against E. coli. Both types of honey showed no effects on Salmonella spp. The potency of honey at 100% concentration was found to be higher than all other concentrations tested. However, no effect was observed at concentration of 6.25% v/v honey in the case of both samples.