WP1 involved the assessment of incidence of heritable symbionts and wider microbiome of bees across the USA and UK. Arsenophonus and Spiroplasma microbes were detected in USA honey bees, with Arsenophonus widespread (with obvious spatial patterns, and some evidence of seasonality); Arsenophonus was also seasonally common int the UK. We have succeeded in culturing, sequencing and formally describing the Arsenophonus symbiont as a novel species for onward work by ourselves and others. A wider look at the microbiome of bees has also been completed with respect to gaining a view on the effects of apiculture on bee microbiome - this involves comparison of feral honey bees to those in apiculture. Analysis of these samples is ongoing.
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.
