The antimicrobial efficacy of Fijian honeys against clinical isolates from diabetic foot ulcers

Abstract

Summary A diverse range of illnesses has been treated with honey since ancient civilizations. There has been growing interest by health care professionals in wound care products based on New Zealand manuka honey and Australian honey of similar Leptospermum spp. In Fiji, local honeys have been used in homes to treat diabetic foot ulcers which have failed to heal by conventional therapeutic methods. This suggests that Fiji honeys may confer antimicrobial activity against the isolates from diabetic foot ulcers and this inference was tested in this study. The antimicrobial activity of 30 natural and two processed honeys was determined using some clinical isolates from diabetic foot ulcers, namely: Staphylococcus aureus, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. The antimicrobial activity of the natural honeys, determined by an agar well diffusion assay and expressed as the concentration of phenol with equivalent activity, was found to be between 4.1 and 14.5% w/v phenol. The mean inhibitory concentrations (MIC) of the honeys determined by an agar incorporation technique, was found to range from 4.8% to more than 9.1% (v/v) honey (9.1% being the highest concentration tested). In comparison, the activities of two processed honeys were between 4.5 - 8.9% phenol equivalence and did not inhibit the clinical isolates from diabetic foot ulcers at the highest concentration of honey tested (9.1%). The results demonstrate that Fijian honeys could be utilized as a herbal remedy for the treatment of diabetic foot ulcers. However, to assess the potential of Fijian honeys on diabetic foot ulcers, there is a need for clinical trials on these wounds.