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

Abstract
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

ACTIVITATEA ANTIBACTERIANĂ IN VITRO A MIERILOR MONOFLORE, ÎMPOTRIVA PATOGENILOR PAENIBACILLUS LARVAE ŞI ESCHERICHIA COLI

Otilia Bobiş, L.Al. Mărghitaş, D.S. Dezmirean, B. Gherman, F. Chirilă

Rezumat
Diferite tipuri de miere monoflora provenind de pe piata romaneasca au fost evaluate pe doi importanti patogeni ai albinelor: Paenibacillus larvae (agentul cauzator al bolii Loca americana) si Escherichia coli (patogen frecvent intalnit in tractul digestiv al albinelor). Compozitia chimica si compusii biologic activi din mierea de salcam (Robinia pseudoacacia), tei (Tillia spp.), rapita (Brassica rapa), floarea soarelui (Helianthus annuus) si iarba neagra (Calluna vulgaris) au fost determinati pentru a stabili autenticitatea botanica si a parametrilor de calitate. Diferite concentratii de solutii de miere si mierea ca atare au fost evaluate pentru capacitatea antimicrobiana, utilizand metoda difuzimetrica. Concentratia minima inhibitorie (CMI) a fost determinata prin metoda dilutiilor succesive, inregistrandu-se diferente intre tipurile de miere analizate. Cele mai bune rezultate au fost obtinute cand s-a utilizat mierea de floarea soarelui si iarba neagra, aceste tipuri de miere prezentand cel mai mare diamentru de inhibitie al celor doi agenti bacterieni si cea mai mica concentratie minima inhibitorie. Sunt necesare in viitor studii in vivo pentru a proba eficacitatea acestor tipuri de miere, si utilizarea lor in prevenirea imbolnavirilor la albine.

Cuvinte cheie: miere monoflora, in vitro, activitate antibacteriana, Paenibacillus larvae, Escherichia coli