Location: Honey Bee ResearchTitle: Draft genome sequences of four parasaccharibacter apium strains isolated from honey bees Author
Submitted to: Genome Announcements
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2018
Publication Date: 3/6/2018
Citation: Corby-Harris, V.L., Anderson, K.E. 2018. Draft genome sequences of four parasaccharibacter apium strains isolated from honey bees. Genome Announcements. https://doi.org/10.1128/genomeA.00165-18.
DOI: https://doi.org/10.1128/genomeA.00165-18 Interpretive Summary: Parasaccharibacter apium is a bacterium that naturally occurs in the honey bee hive. Some strains benefit their honey bee host and recent work suggests that P. apium can be detrimental under certain stressful circumstances. To more fully describe the relationship of this bacterium to other closely related taxa and to determine whether certain genes could explain the benefit, we sequenced the genomes of beneficial P. apium and P. apium strains that do not positively impact honey bee health. We were not able to identify certain “beneficial” genes, suggesting that the benefit might come from differences in gene expression rather than qualitative differences in gene content. Comparisons between P. apium and other species of related bacteria indicate that it this bacterium is remarkably flexible and has metabolic features that allow it to survive and effectively compete with other bacterium in cases where resources are scarce or the environment is harsh. Further surveys of P. apium in the hive combined with laboratory and field assays will help to shed light on strain-level differences in how this bacterium impacts its honey bee host.
Technical Abstract: Parasaccharibacter apium is a newly described bacterium of honey bees that exhibits multiple ecological strategies in their host, from beneficial to pathogenic. Using niche-specific 16S rRNA gene sequences and bacterial genomes, we describe the ecology of this bacterium and its relationship to other closely related bacteria. Although typically excluded from the worker gut, P. apium is abundant in nurse workers, larvae, worker jelly, and queen guts and found throughout the hive environment. Phylogenetic analyses support the distinction between P. apium and the closely related S. floricola. The genomes of four P. apium isolates from larvae and an adult hindgut were similar in gene content but could be distinguished based on sequence-level variability in genes shared among the strains and the differential arrangement of CRISPR regions. Further, features in the P. apium genome suggest that this bacterium can tolerate potentially extreme hive environments and compete with other microbes for resource space in the gut environment. This, in addition to its exploitation of the feeding behavior between nurses, larvae, and queens, may explain P. apium’s omnipresence throughout the hive. These data offer insight into the ecology and diversity of P. apium and provide a set of new hypotheses for how this bacterium is able to proliferate in the honey bee hive.