Antimicrobial potential of Sicilian honeys against commensal Escherichia coli and pathogenic Salmonella serovar Infantis

Introduction. The purpose of this study was to investigate the antibacterial effect of 71 locally produced honeys from different botanical sources collected from apiarist’s open markets in Sicily. Methods. Antimicrobial activity was determined against Escherichia coli (ATCC 25922) and Salmonella serovar Infantis (ATCC 1523) by an agar-diffusion assay from the estimation of the diameter of the inhibition zone produced by the honeys. Statistically significant differences (P < .000) regarding inhibition were observed for the honeys tested. Results. The chestnut and polyfloral honey samples exhibited the largest and highest inhibition (diameter of the inhibition zone > 25 mm) against both E. coli and S. Infantis. The honey of oregano origin showed intermediate or low activity against E. coli and S. Infantis, respectively. Prickly pear and erica honeys showed no antimicrobial activity against the two reference strains. Discussion. The results may partially suggest the usefulness of the Sicilian honeys on treating multi-resistant enterobacteria. In light of the enormous potential for application of honey in the clinical practice, it is important that research continues not only into those honeys well recognized as antimicrobial, but also into other locally produced and yet untested honeys.