Development of a probiotic mixture based on Lactobacillus kunkeei, to improve honeybee health

ARREDONDO, D.; PORRINI M. P.; GARRIDO P. M.; EGUARAS M, J.; ZUNINO, P.; ANTÚNEZ K.

Murcia

Conferencia; EurBee 6; 2014

Native intestinal microbial community is essential to maintain an adequate nutrition, health and immunity against pathogens. The administration of probiotics as feed aditives is a widely used strategy, both in humans and animals, in order to improve health. In a previous work we obtained and characterized a collection of isolates from the midgut microbial community of healthy honey bees. Ten isolates were selected based on their biological characteristics (in vitro inhibition of Paenibacillus larvae, resistance to high sugar levels and low pH values, production of lactic acid, among others). The aim of this study was to evaluate those isolates as potential probiotics. We assessed their in vivo pathogenicity on larvae and adult bees; their in vivo effect against Paenibacillus larvae and Nosema ceranae, and their ability to modulate the immune system of adult bees. After oral administration of the bacterial preparations in sugar syrup, none of them resulted pathogenic for adult bees or larvae. Regarding their effect against pathogens, an increased viability was found in P. larvae infected larvae, when a mixture of Lactobacillus kunkeei strains was added to their food. This mixture was also able to decrease the infection levels by N. ceranae spores. Finally, those isolates were able to modulate the expression of genes related to immunity. These results suggest that L. kunkeei strains are promising candidates to be used in a probiotic preparation to improve honeybee health. Further assays are needed to assess their effect on colonies in the field.