In vitro characterization of antibacterial potential of Iranian honey samples against wound bacteria

Incidence of multidrug-resistant pathogens is increasing, thus discovery of alternative therapeutic agents is needed. Honey possesses therapeutic potential, including wound-healing properties and antimicrobial activities. Although antimicrobial activity of honey has been effectively established, the antibacterial properties of Iranian honey samples on wound microorganisms have not been conducted and compared with honey gold standards. Using standard methods, the antibacterial activities of 53 Iranian honey samples and two laboratory-synthesized honeys against 16 drug-resistant clinical isolates and four reference strains were determined. Different concentrations of honey were tested against each type of microorganism to determine the minimum inhibitory concentration (MIC) or minimum bactericidal concentration. The selected honeys with high levels of phenolic equivalent were studied for kinetics of bacterial killing. Also, the ability of selected honey samples to prevent biofilm formation was checked by crystal violet assay. The MICs of Iranian honey samples ranged from 3.12 to > 50 % (w/v), and their efficacies were also determined. Nine samples with the highest antibacterial activities were selected. Survival of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa was reduced significantly by selected honeys. Moreover, all selected honey samples were able to prevent biofilm formation of S. aureus and P. aeruginosa strains at concentrations of a parts per thousand currency sign25 %. The results of the present study have shown that selected Iranian honey samples had lower MIC values than reported standard honeys such as Manuka and Tualang and could be potentially used as alternative medical grade honey, particularly against S. aureus, P. aeruginosa, and E. coli.