Periodic Reporting for period 2 - BeeSymOverSpace (How to help the hive? Incidence and impact of heritable microbes on bee health)
Berichtszeitraum: 2018-06-01 bis 2019-05-31
WP2 is based around the impact that heritable symbionts have in their honeybee hosts. We have completed the genome sequence for Arsenophonus from bees, alongside its first isolation in cell free culture and formal description is ongoing, with Dr Burritt and lab members. Experimental analysis of the impact of Spiroplasma and Arsenophonus on bee survival, and also susceptibility to other pathogens (Nosema, deformed wing virus) has been completed, and indicates these are not primary pathogens, in that healthy bees were able to clear infection with little ill effect. However, impacts in unhealthy bees are suspected, making these microbes opportunistic pathogens that may be important under colony stress. We have also completed an experiment examining how these microbes affect host immune function directly.
WP3 involves interface with users; our results indicate these symbionts are not key to bee health, but may emerge as important agents in combination with other external issues (pesticides, mite attack). Thus husbandry to avoid these attacks are key in minimizing deleterious impacts of these microbial symbionts. We have met with representatives of fera (food and environment research agency) and the national bee unit (part of UK DEFRA) to outline the results and their consequences for husbandry. We have also written a report for Bee Disease Insurance, a commercial company that insures beekeepers against losses from hive declines, with respect to our work.
Dissemination activities have additionally involved the academic community, and school children in the UK.
Overall, our work provides the first comprehensive picture of Arsenophonus and Spiroplasma in honey bees, and their impact on the host.
Description of the geographic and temporal basis of the symbiosis is completed for the first time, alongside analyses of patterns of infection. These demonstrate profound seasonal dynamics, with Arsenophonus increasing towards autumn, and Spiroplasma in the Spring. Thus these microbes impact honey bees at different times of year.
Impact of Spiroplasma and Arsenophonus on bee health were determined under laboratory assay, alongside impacts on host transcriptional profile. These demonstrate neither is an important associate of healthy bees, though they may be pathological in unhealthy or stressed hives.
Together, these have demonstrated these symbionts are common in honey bees, have seasonal incidence, but are not major impactors on health in the 'healthy hive' scenario.