IN VITRO ANTIBACTERIAL ACTIVITY OF UNIFLORAL HONEYS AGAINST HONEYBEE PATHOGENS PAENIBACILLUS LARVAE AND ESCHERICHIA COLI
Otilia Bobiş, L.Al. Mărghitaş, D.S. Dezmirean, B. Gherman, F. Chirilă
Different unifloral honeys from Romanian market were evaluated against two important honeybee pathogens: Paenibacillus larvae (causative agent of American foulbrood) and Escherichia coli (frequently found in honeybee digestive tract). Chemical composition as well as biologically active compounds from black locust (Robinia pseudoacacia), linden (Tillia spp.), canola (Brassica rapa), sunflower (Helianthus annuus) and heather honey (Calluna vulgaris) were determined in order to establish the authenticity in respect of botanical origin and quality parameters. Different concentrations of honey solutions as well as entire raw honey were evaluated for antimicrobial capacity using difuzimetric method. Minimum inhibitory concentration (MIC) was determined by succesive dillutions method and diferences between honey types were registered. Best results were obtained by using sunflower and heather honey, these two types presenting the highest diameter of inhibition for the two bacteries and the lowest minimum inhibitory concentration. Further in vivo studies are necessary to prove the efficacity of these honey types and their utilization in preventing bee diseases.
Key words: unifloral honey, antibacterial activity, Paenibacillus larvae, Escherichia coli