The sensitivity of mastitis-causing bacteria to the antibacterial activity of honey

The use of honey as a wound dressing is well established in traditional and modern medicine. There are many reports of its effectiveness in clearing bacterial infections in ulcers and abscesses, which suggest that it may be suitable for the intramammary treatment of mastitis. To evaluate this possibility, the species of bacteria that commonly cause mastitis in dairy cows were tested for their sensitivity to the antibacterial activity of honey. The growth of all seven species tested was completely inhibited by a typical honey (with antibacterial activity attributed to its content of hydrogen peroxide) at a concentration of 10% (v/v) in the agar plates, and two by 5% honey. Six of the species were completely inhibited by a typical manuka honey (with antibacterial activity attributed to its content of a non-peroxide component) at a concentration of 5% (v/v). Only one species was inhibited by 10% (v/v) artificial honey (sugars and gluconic acid as in honey). As honey is harmless to tissues and would leave no undesirable residues in milk, it would be of interest to now evaluate it therapeutically in clinical mastitis.