Pollen covered in bacteria from the honey bee jindgut



1) Flower- and bee-associated microbiomes. One of our research foci is on the microbiomes associated with wild bees. In our earlier work, we discovered undescribed bacteria that we isolated from both flowers and wild bees. We recently used new whole-genome sequences and traditional microbiology techniques to formally describe three new bacterial species, which we named after prominent bee biologists. We recently completed a comparative genomics project with 30 genomes of these and related bacteria. We have also found that these bacteria can inhibit the growth of certain fungi in vitro. Former McFrederick lab postdoc Graystock described the core microbiome of several wild bee species, focusing on relationships between bacteria found in pollen and the bee host  With collaborator Sandra Rehan, I described how pollen usage drives differences in fungal and bacterial communities across disparate landscapes. This work highlights how the availability of different flowers in different landscapes alters the fungal (and, to a lesser extent, bacterial) communities found in bee food. The McFrederick lab’s work in this area is beginning to coalesce into an understanding of how bee foraging influences associated microbial communities.

Larva and mycelia

2) Bee pathogens. While honey bee diseases are well studied, we know very little about the pathogens and parasites of most other bees. As co-PI on an NIH-funded grant, we are exploring disease transmission in pollination networks. We recently finished screening 3,000 bee samples for a panel of diseases and are currently finishing a four host, four pathogen cross-species infection experiment. As co-PI on an NSF–funded project (with PI Wilson-Rankin), we are studying the impact of migratory pollinators on disease in resident populations. Postdoc Evan Palmer-Young (now at Carl Hayden Bee Research Center in Tucson) showed that higher body temperatures in bumble bees affects interactions between an intestinal parasite and the gut microbiome. 

Nosema ceranae

(3) Microbes and environmental toxins. We have several completed and ongoing projects that are increasing our ability to leverage microbes to protect bees from environmental toxins such as soil contaminants and pesticides. For example, graduate student Jason Rothman recently showed that the bumble bee microbiome increases host survival when challenged with field-realistic doses of selenium.

(4) Microbes and honey bee health. Graduate student Rothman showed that supplemental winter forage has surprisingly subtle effects on the honey bee worker microbiome. With James Nieh's group at UCSD, we showed that certain Gilliamella apicola strains positively correlate with Nosema ceranae colony susceptibility. We are currently collaborating with Kirk Anderson, Elina Nino, and Neal Williams to understand the effects of supplemental forage on honey bee immune function and disease.

Pollen covered in bacteria from the honey bee jindgut