Variability in Antimicrobial Properties of Multifloral Honey in Southwestern Virginia

The antimicrobial properties of multifloral honey have been utilized for centuries in wound healing, as well as for infection treatment and prevention. The chemical properties from the nectar source, enzymes produced by the bee, as well as the digestive activity of the microorganisms in the bee gut all contribute to the antimicrobial activity of honey. Honeybee (Apis mellifera, the western or European Honeybee) farms in four locations across southwestern Virginia (Fincastle, Covington, Troutville, and Martinsville) were visited in the fall of 2021 to collect honey (fall and spring), worker bees, and pollen pellets. Disk diffusion assays were used to assess the antimicrobial activity of fall and spring honey against ESKAPE pathogens. Pollen analysis was completed on the spring honey and fall pollen pellets to identify the plant species on which the bees were foraging at each time of year. Lastly, the honeybee gut was dissected, and the microorganisms within the midgut and hindgut were isolated and identified using 16S rRNA gene sequencing to identify the cultivable microbial community in the bee gut. Martinsville spring honey demonstrated the strongest antimicrobial properties among spring and fall honey among sample site. Fall honey generally demonstrated stronger antimicrobial properties than spring honey and manuka honey (a monofloral honey from the Manuka bush in New Zealand and known to have strong antimicrobial properties). Fincastle spring honey had the most species diversity in foraged pollen, and tree pollen was unexpectedly found to be significant in bee diet. Lastly, the gut microbes identified produce antimicrobial properties, mostly antimicrobial peptides (AMPs) produced by Bacillus species