Differences in honey bee bacterial diversity and composition in agricultural and pristine environments – a field study

Agrochemicals and biocides are suspected to cause a dysbiosis of honey bee microbiota, decreasing colonies ability to respond to the environment. As a first step to investigate agriculture and beekeeping impact, hives bacteriomes from an anthropized environment (Agri-env) were compared to that of pristine’s (Prist-env). 16S rRNA sequencing evidenced differences in richness and composition between sample types (Gut (G), Brood (B), Bee-bread (BB)) and environments. Higher opportunist loads and shifts toward taxa capable of metabolizing insecticides were observed in G and B at Agri-env, while beneficial bacteria were enriched in Prist-env. Bacteria in BB did not differ, the acidity of the niche outweighing the influence of external factors. Results showed the environment plays a major role in shaping honey bee microbiota, the agricultural realm inducing a bacterial disruption that would let to colonies vulnerability. In contrast, a less susceptible bee will be promoted in less anthropized locations.