Impact of Nutritional Stress on Honeybee Gut Microbiota, Immunity, and Nosema ceranae Infection

CASTELLI, L.; BRANCHICCELA, B.; GARRIDO, M.; INVERNIZZI, C.; PORRINI, M.; ROMERO, H.; SANTOS, E.; ZUNINO, P.; ANTÚNEZ, K.

MICROBIAL ECOLOGY

SPRINGER

Año: 2020

0095-3628

Honeybees are important pollinators, having an essential role in the ecology of natural and agricultural environments.Honeybee colony losses episodes reported worldwide and have been associated with different pests and pathogens,pesticide exposure, and nutritional stress. This nutritional stress is related to the increase in monoculture areas whichleads to a reduction of pollen availability and diversity. In this study, we examined whether nutritional stress affectshoneybee gut microbiota, bee immunity, and infection byNosema ceranae, under laboratory conditions. Consumption ofEucalyptus grandispollen was used as a nutritionally poor-quality diet to study nutritional stress, in contraposition to theconsumption of polyfloral pollen. Honeybees feed withEucalyptus grandispollen showed a lower abundance ofLactobacillus melliferandLactobacillus apis(Firm-4 and Firm-5, respectively) andBifidobacteriumspp. and a higherabundance ofBartonella apis, than honeybees fed with polyfloral pollen. Besides the impact of nutritional stress onhoneybee microbiota, it also decreasedthe expression levels of vitellogenin and genes associated to immunity (glucoseoxidase, hymenoptaecin and lysozyme). Finally,Eucalyptus grandispollen favored the multiplication ofNosemaceranae. These results show that nutritional stress impacts the honeybee gut microbiota, having consequences onhoneybee immunity and pathogen development. Those results may be useful to understand the influence of modernagriculture on honeybee health.