title: Deep sequencing and ecological characterization of gut microbial communities of diverse bumble bee species.
abstract: Gut bacterial communities of bumble bees are correlated with defense against pathogens. Further understanding this host-microbe association is vitally important as bumble bees are currently experiencing global population declines, potentially due in part to emergent diseases. In this study, we used pyrosequencing and community fingerprinting (ARISA) to characterize the gut microbial communities of nine bumble species from across the Bombus phylogeny. Overall, we delimited 74 bacterial taxa (operational taxonomic units or OTUs) belonging to Betaproteobacteria, Gammaproteobacteria, Bacilli, Actinobacteria, Flavobacteria and Alphaproteobacteria. Each bacterial community was taxonomically simple, containing an average of 1.9 common (relative abundance per sample > 5%) bacterial OTUs. The most abundant and prevalent (occurring in 92% of the samples) bacterial OTU, based on 16S rRNA sequences, closely matched that of the previously described Betaproteobacteria species Snodgrassella alvi. Bacteria that were first described in bee-related external environments dominated a number of gut bacterial communities, suggesting that they are not strictly dependent on the internal gut environment. The ARISA data showed a correlation between bacterial community structures and the geographic locations where the bees were sampled, suggesting that at least a subset of the bacterial species may be transmitted environmentally. Using light and fluorescent microscopy, we demonstrated that the gut bacteria form a biofilm on the internal epithelial surface of the ileum, corroborating results obtained from Apis mellifera.
authors.affiliation: Department of Entomology, University of Illinois, Urbana, IL, 61801, United States of America.
authors.forename: Haw Chuan
authors.initials: HC
authors.lastname: Lim
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, IL, 61801, United States of America.
authors.forename: Chia-Ching
authors.initials: CC
authors.lastname: Chu
authors.affiliation: Department of Entomology, University of Illinois, Urbana, IL, 61801, United States of America.
authors.forename: Manfredo J
authors.initials: MJ
authors.lastname: Seufferheld
authors.affiliation: Department of Entomology, University of Illinois, Urbana, IL, 61801, United States of America.
authors.forename: Sydney A
authors.initials: SA
authors.lastname: Cameron
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics*; D001516:Bees / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development; D004463:Ecology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017421:Sequence Analysis / Q000379:methods; D013559:Symbiosis / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S