Asian Journal of Applied Sciences (ISSN: 2321 – 0893) Volume 02 – Issue 02, April 2014 Asian Online Journals (www.ajouronline.com ) 110 Comparative Antibacterial and Antibiofilm Activities of Manuka Honey and Egyptian Clover Honey Hisham A. Abbas Department of Microbiology and Immunology Faculty of PharmacyZagazig University Zagazig- Egypt Email: h_abdelmonem {at} yahoo.com ABSTRACT--- The antibacterial and antibiofilm activities of Manuka and Egyptian clover honey against five clinical isolates of each of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella spp. and Proteus mirabilis isolated from diabetic foot ulcers were compared. The antibacterial activity was estimated by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Manuka honey showed higher antibacterial activities than clover honey as shown by lower MIC and MBC values. Pseudomonas aeruginosa and Proteus mirabilis showed higher sensitivity to manuka honey than Klebsiella spp. and Staphylococcus aureus. Both types of honey showed bactericidal activities against all tested strains. The antibiofilm activities were investigated against one strong biofilm forming isolate of each strain. The antibiofilm activities of Manuka honey were significantly more potent than clover honey. The biofilm inhibiting activity of manuka honey was greater against Klebsiella spp., Proteus mirabilis and Pseudomonas aeruginosa. Clover honey showed greater biofilm inhibiting activity against Klebsiella spp. and Proteus mirabilis. Biofilm disrupting activity of manuka honey was higher against Pseudomonas aeruginosa and Proteus mirabilis, while clover exerted higher biofilm eradication activity against Klebsiella spp. and Pseudomonas aeruginosa. This study suggests the use of manuka and Egyptian clover honey for treatment of diabetic foot infections. Manuka honey was more effective but Egyptian clover honey is cheaper. Keywords--- Manuka honey; Clover honey; antibacterial; antibiofilm; diabetic foot infection 1. INTRODUCTION Diabetic patients suffer from different complications including neuropathy and vascular problems that contribute to the occurrence of diabetic foot infections. These infections are hazardous and can end with diabetic gangrene and amputation of lower limbs [1,2]. Many bacteria can infect diabetic wounds and the most common ones are Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pnuemoniae, Escherichia coli and Proteus mirabilis [3-5]. Infected wounds in patients with impaired immunity or circulation as in diabetic patients may be non-healing and chronic. Biofilms play an important role in diabetic foot infections. Biofilms are communities of sessile cells that are attached to a surface and enclosed within a matrix and they show high antimicrobial resistance [6,7]. The increase in emergence of antibiotic resistance among bacteria infecting wounds complicates the treatment. As a consequence, alternative therapeutic options are urgently needed to treat diabetic foot ulcers [8,9]. Honey has a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. Moreover, it could inhibit biofilm formation and eradicate established biofilms [10,11]. Manuka honey is produced from Leptospermum scoparium (manuka) plant from New Zealand. It is a promising tool in the fight against bacteria. It has a broad antibacterial spectrum and could inhibit multi-drug resistant bacteria [12-14]. Moreover, it was found to inhibit biofilm formation and to remove pre-formed biofilms [15,16]. No resistance to manuka honey was reported [12-14]. More beneficial activities of manuka honey are its stimulating effect on immunity and wound healing [17]. Egyptian clover honey was reported to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae and Proteus mirabilis [18,19]. The aim of the present study is to compare the antimicrobial and antibiofilm activities of manuka and Egyptian clover honeys against bacteria isolated from diabetic foot infections.