Bactericidal activity of different honeys against pathogenic bacteria

Renewed interest in honey for various therapeutic purposes including treatment of infected wounds has led to the search for new antibacterial honeys. In this study we have assessed the antibacterial activity of three locally produced honeys and compared them to three commercial therapeutic honeys (including Medihoney and manuka honey).

An agar dilution method was used to assess the activity of honeys against 13 bacteria and one yeast. The honeys were tested at five concentrations ranging from 0.1 to 20%.

Twelve of the 13 bacteria were inhibited by all honeys used in this study with only Serratia marcescens and the yeast Candida albicans not inhibited by the honeys. Little or no antibacterial activity was seen at honey concentrations <1%, with minimal inhibition at 5%. No honey was able to produce complete inhibition of bacterial growth. Although Medihoney and manuka had the overall best activity, the locally produced honeys had equivalent inhibitory activity for some, but not all, bacteria.

Honeys other than those commercially available as antibacterial honeys can have equivalent antibacterial activity. These newly identified antibacterial honeys may prove to be a valuable source of future therapeutic honeys.