Antibacterial activity of honeydew honey samples (n = 23) and medical-grade manuka and kanuka honey following catalase and proteinase K treatment against (A) Staphylococcus aureus and (B) Pseudomonas aeruginosa isolates. The 50% (w/v) honey solutions were treated with catalase (2000–5000 U/mg protein) at a final concentration ranging from 1000 to 2500 U/ml at room temperature for 2 h or proteinase K (30 U/mg) at a final concentration of 50 μg/ml at 37 °C for 30 min. The antibacterial activity was determined with a minimum inhibitory concentration (MIC) assay. The MIC was defined as the lowest concentration of honey solution (%) inhibiting bacterial growth. K, kanuka honey; M, manuka honey.