Survey of Antibacterial Effects of Thymus Vulgaris Ethanolic Extract on the Paenibacillus larvae, the Causative Agent of Honeybee American Foulbrood Disease and Its Safety for Adult Honeybees

In this study, the antibacterial effects of thyme ethanolic extract on the  Paenibacillus larvae, the Causative agent of  honeybee American Foulbrood Disease were studied and the effect of this extract was studied on the adult bees. First, the leaves of the thyme were extracted using ethanol. Paenibacillus larvae was subjected todifferent dilutions of thymus vulgaris extract by two Agar Diffusion and Broth Dilution. Also, adult honey bees were fed with different dilutions of thyme extract.Different dilutions of thyme extracts inhibited the growth of Paenibacillus larvae in the culture medium, and there was a significant difference between the treatments and control groups (P<0.005). Also, different dilutions of thyme extract had not any side effects on the treated adult bees, in comparison with control groups.The results of this study showed that alcoholic extract of thymus vulgaris has a high antibacterial effect on Paenibacillus larvae, the causative agent of American Foulbrood disease in the culture medium. On the other hand, this extract is safe for adult honeybees and can  be used as a remedy for American Foulbrood disease in the bee colonies.