Analysis of the gut microbiome of susceptible and resistant honeybees (Apis cerana) against sacbrood virus disease

Abstract The global decline in the population of wild bees has raised serious concerns, as bees are key pollinators that contribute to the sustainability of agriculture. Especially alarming, are the millions of managed bees in Korea that have recently disappeared. Although many abiotic and biotic stresses influence their physiology and behaviour, the causes of these declines have not been thoroughly elucidated. In recent studies, bee gut microbiota was found to play an important role in pathogen defence. We hypothesized that the gut microbiome of honeybees ( Apis cerana ) resistant (RH and RR) and susceptible (RL) to sacbrood virus disease may differ. To compare the gut bacterial communities of resistant and susceptible bees, alpha diversity and beta diversity analyses were performed. The analysis of alpha diversity revealed that RH had significantly higher Shannon diversity index values than RL. Beta diversity analysis showed that the gut bacterial community of RH was significantly different from that of RL. Four bacterial phyla were identified, and proteobacteria was the most abundant across all samples. Additionally, three operational taxonomic units (OTUs) belonging to Pasteurellales, Burkholderiales, and Pseudomonadales were identified only in RL. In conclusion, the gut bacterial community was significantly different between resistant and susceptible bees, and this difference may contribute to disease resistance.