Antibacterial, Antifungal and Antibiofilm Activity of Methylglyoxal: A Phytochemical from Manuka Honey

Abstract

Introduction: Honey has been known for its ability to promote wound healing for a long time. It is utilized for several skin and soft tissue infections caused by a wide range of microorganisms due to its antimicrobial property. Methylglyoxal (MGO), the unique antibacterial compound contained by Manuka honey, is believed as the reason for the antimicrobial activity of Manuka honey. This study aims to identify the antibacterial, antifungal and anti-adherent activity of MGO in changing concentrations and determine the viable number of bacteria and fungi in biofilm after the treatment of MGO. Materials and Methods: Antibacterial and antifungal activity of MGO was determined by broth microdilution method for identifying minimum inhibitory and bactericidal and fungicidal concentrations (MIC, MBC and MFC, respectively). Percentage of biofilm formation inhibition and the number of viable microorganisms in biofilm after the MGO treatment was determined by the colony-forming unit method. Results: Minimum inhibitory concentration values for the bacterial strains ranged from 0.0078 to 0.125% (v/v), while MBC ranged from 0.0312 to 2% (v/v). Among fungi, MIC and MFC values were higher than those for tested bacterial strains; MIC values ranged from 0.0156 to 1% (v/v), while MFC values ranged from 0.0625 to 2% (v/v). Methylglyoxal was able to prevent biofilm formation in the all tested biofilm forming isolates. Number of viable bacteria, even in the sub-inhibitory doses of MGO, reduced remarkably. Conclusion: Unique compound of Manuka honey, MGO, exerts significant antimicrobial and antibiofilm activity against clinically important strains of both bacteria and fungi which may be utilized for the search of promising alternatives for antibiotics and may lead to combat antibiotic resistance.

Keywords

• methylglyoxal
• antibacterial
• antifungal
• antibiofilm