Transmission pathways have fundamental influence on microbial symbiont persistence and evolution. For example, the core gut microbiome of honey bees is transmitted socially and via hive surfaces, but some non-core bacteria associated with honey bees are also found on flowers, and these bacteria may therefore be transmitted indirectly between bees via flowers. Here, we test whether multiple flower and wild megachilid bee species share microbes, which would suggest that flowers may act as hubs of microbial transmission. We sampled the microbiomes of flowers (either bagged to exclude bees or open to allow bee visitation), adults, and larvae of seven megachilid bee species and their pollen provisions. We found a Lactobacillus operational taxonomic unit (OTU) in all samples but in the highest relative and absolute abundances in adult and larval bee guts and pollen provisions. The presence of the same bacterial types in open and bagged flowers, pollen provisions, and bees supports the hypothesis that flowers act as hubs of transmission of these bacteria between bees. The presence of bee-associated bacteria in flowers that have not been visited by bees suggests that these bacteria may also be transmitted to flowers via plant surfaces, the air, or minute insect vectors such as thrips. Phylogenetic analyses of nearly full-length 16S rRNA gene sequences indicated that the Lactobacillus OTU dominating in flower- and megachilid-associated microbiomes is monophyletic, and we propose the name Lactobacillus micheneri sp. nov. for this bacterium.

The honey bee, Apis mellifera , pollinates a wide variety of essential crops in numerous ecosystems around the world but faces many modern challenges. Among these, the microsporidian pathogen Nosema ceranae is one of the primary detriments to honey bee health. Nosema infects the honey bee gut, which harbors a highly specific, coevolved microbiota heavily involved in bee immune function and nutrition. Here, we extend previous work investigating interactions between the honey bee gut microbiome and N . ceranae by studying experimentally infected bees that were returned to their colonies and sampled 5, 10, and 21 days post-infection. We measured Nosema load with quantitative PCR and characterized microbiota with 16S rRNA gene amplicon sequencing. We found significant colony level variation in infection levels, and subtle differences between the microbiota of colonies with high infection levels versus those with low infection levels. Two exact sequence variants of Gilliamella , a core gut symbiont that has previously been associated with gut dysbiosis, were significantly more abundant in bees from colonies with high Nosema loads versus those with low Nosema loads. These bacteria deserve further study to determine if they facilitate more intense infection by Nosema ceranae .

Summary Bumble bees are important and widespread insect pollinators who face many environmental challenges. For example, bees are exposed to the metalloid selenate when foraging on pollen and nectar from plants growing in contaminated soils. As it has been shown that the microbiome of animals reduces metalloid toxicity, we assayed the ability of the bee microbiome to increase survivorship against selenate challenge. We exposed uninoculated or microbiota‐inoculated Bombus impatiens workers to a field‐realistic dose of 0.75 mg l−1 selenate and found that microbiota‐inoculated bees survive slightly but significantly longer than uninoculated bees. Using 16S rRNA gene sequencing, we found that selenate exposure altered gut microbial community composition and relative abundance of specific core bacteria. We also grew two core bumble bee microbes – Snodgrassella alvi and Lactobacillus bombicola – in selenate‐spiked media and found that these bacteria grew in the tested concentrations of 0.001–10 mg l−1 selenate. Furthermore, the genomes of these microbes harbour genes involved in selenate detoxification. The bumble bee microbiome slightly increases survivorship when the host is exposed to selenate, but the specific mechanisms and colony‐level benefits under natural settings require further study.

Abstract Recent declines of wild pollinators and infections in honey, bumble and other bee species have raised concerns about pathogen spillover from managed honey and bumble bees to other pollinators. Parasites of honey and bumble bees include trypanosomatids and microsporidia that often exhibit low host specificity, suggesting potential for spillover to co-occurring bees via shared floral resources. However, experimental tests of trypanosomatid and microsporidial cross-infectivity outside of managed honey and bumble bees are scarce. To characterize potential cross-infectivity of honey and bumble bee-associated parasites, we inoculated three trypanosomatids and one microsporidian into five potential hosts – including four managed species – from the apid, halictid and megachilid bee families. We found evidence of cross-infection by the trypanosomatids Crithidia bombi and C. mellificae, with evidence for replication in 3/5 and 3/4 host species, respectively. These include the first reports of experimental C. bombi infection in Megachile rotundata and Osmia lignaria, and C. mellificae infection in O. lignaria and Halictus ligatus. Although inability to control amounts inoculated in O. lignaria and H. ligatus hindered estimates of parasite replication, our findings suggest a broad host range in these trypanosomatids, and underscore the need to quantify disease-mediated threats of managed social bees to sympatric pollinators.

Study Objective: To analyze the nature and accuracy of social media (Facebook) content related to endometriosis. Design: Retrospective content analysis. Setting: Social media platform, Facebook. Participants: Social media posts on Facebook endometriosis pages. Interventions: A search of public Facebook pages was performed using the key word "endometriosis." Posts from the month-long study period were categorized and analyzed for accuracy. Two independent researchers used thematic evaluation to place posts into the following 11 categories: educational, emotional support, advocacy, discussion, events, humor, promotional, recipes, resources, surveys, and other. Posts categorized as educational were further subcategorized and reviewed. Each posted fact was cross-referenced in peer-reviewed scientific journals to determine whether the claim made was evidence-based. Engagement in a post was calculated by taking the sum of comments, shares, and reactions. Measurements and Main Results: A total of 53 Facebook pages meeting inclusion criteria were identified and 1464 posts from the study period were evaluated. Emotional support posts comprised the largest category of posts (48%) followed by educational posts (21%). Within the educational category, the epidemiology and pathophysiology subcategory comprised the largest group (42.0%) followed by the symptom's subcategory (19.6%). Post category had an effect on the amount of post engagement (p-value <.001) with emotional posts generating 70% of the overall engagement. The subcategories of the educational posts demonstrated a similar effect on engagement (p-value <.001). Posts were more engaging if they contained epidemiology and pathophysiology information with 44% of all engagement of educational posts occurring within this subcategory. Educational posts were found to be 93.93% accurate. There was no correlation between post engagement and post information accuracy (p-value = .312). Conclusion: Facebook pages offer emotional support and education to people with endometriosis. Most information found in these Facebook pages is evidence-based. Clinicians should consider discussing the use of Facebook pages with their patients diagnosed with endometriosis.