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ARS Home » Pacific West Area » Tucson, Arizona » Honey Bee Research » Research » Research Project #437900

Research Project: The Honey Bee Microbiome in Health and Disease

Location: Honey Bee Research

Project Number: 2022-21000-021-00-D
Project Type: In-House Appropriated

Start Date: Mar 12, 2020
End Date: Mar 11, 2025

Objective:
Our long-term objective is to understand the structure and function of the honey bee microbiome in health and disease. Using a combination of laboratory and field approaches we will further our understanding of the diversity, abundance, persistence and functional capacities of the microorganisms that occur in the hive environment, the alimentary tracts of queens, workers and developing larvae. This information will be applied to the diagnosis and management of disease associated with commercial beekeeping. Industry applications include management strategies to reduce the severity of brood disease, diagnostic tools for queen health and productivity, and a novel context to assess disease prevention and progression. The studies outlined in this Project Plan are directed at understanding the healthy microbial balance of a honey bee colony, with particular emphasis on dysbiotic states as precursors to disease. In a social insect like the honey bee, disease must be considered at many levels of organization (Evans and Spivak 2010). This rule also applies to beneficial host-microbe associations. We hypothesize that bacteria commonly shared among developmental stages, tissues, and reproductive castes may represent cryptic drivers of disease evolution (Figure 1). The long-term objective of this project is to identify native microbes that promote or discourage disease. Specifically, during the next five years we will focus on the following objectives. Objective 1: Develop an integrated research approach (e.g. improved sampling and analytical methods) for the understanding and the management of honey bee larval microbiota, immune priming and brood disease. [NP305, Component 2, Problem Statements 2A and 2B] (Anderson) Sub-objective 1A: Enumerate, identify, and characterize the microbial succession of healthy and diseased larvae. (Anderson) Sub-objective 1B: Identify the species and interactions that cause or contribute to larval disease and/or affect larval immune response. (Anderson) Objective 2: Analyze the population dynamics of the adult honey bee gut microbiota, and extended microbiota, with reference to species and strain variation, ecological niches, potential for functional redundancy, and corresponding host responses. [NP305, Component 2, Problem Statement 2B] (Anderson, Carroll) Sub-objective 2A: Determine gut succession of the queen microbiota with respect to bacterial function, occupied niche, hive environment and host gene expression. (Anderson) Sub-objective 2B: Determine how worker trophallactic feeding of queens is associated with the microbiota, queen quality, and worker-queen interactions in established queens. (Carroll, Anderson) Objective 3: Investigate the effects of plant compounds on honey bee microbiota, their contributions to bee immunity, and their detoxification at the individual and colony-levels. [NP305, Component 2, Problem Statements 2A and 2B] (Anderson, Palmer-Young) Sub-objective 3A: Determine the effect of plant secondary metabolites on microbial health of workers. (Palmer-Young, Anderson) Sub-objective 3B: Determine the effect of recalcitrant polysaccharides on host-microbial function in workers. (Anderson)

Approach:
Objective 1. Develop an integrated research approach (e.g. improved sampling and analytical methods) for the understanding and the management of honey bee larval microbiota, immune priming and brood disease. [NP305, Component 2, Problem Statements 2A and 2B] (Anderson) Sub-objective 1A: Enumerate, identify, and characterize the microbial succession of healthy and diseased larvae. Hypothesis 1A: The microbial communities associated with phenotypically healthy and diseased larvae do not differ. Sub-objective 1B: Identify the species and interactions that cause or contribute to larval disease and/or affect larval immune response (Anderson) Hypothesis 1B: Larval disease defined phenotypically as EFB or EFB-like is due solely to M. plutonius. Objective 2: Analyze the population dynamics of the adult honey bee gut microbiota, and extended microbiota, with reference to species and strain variation, ecological niches, potential for functional redundancy, and corresponding host responses. [NP305, Component 2, Problem Statement 2B] (Anderson, Carroll) Sub-objective 2A: Determine gut succession of the queen microbiota with respect to bacterial function, occupied niche, hive environment and host gene expression. (Anderson) Hypothesis 2A: Microbial succession of queen alimentary tracts and host gene expression does not differ by niche and early hive environment. Sub-objective 2B: Determine how worker trophallactic feeding of queens is associated with the microbiota, queen quality, and worker-queen interactions in established queens. (Carroll, Anderson) Hypothesis 2B: Selective trophallactic feeding of queens by workers is associated with the queen or worker microbiota, queen and worker quality, and worker-queen interactions mediated by pheromone exchanges. Objective 3: Investigate the effects of plant compounds on honey bee microbiota, their contributions to bee immunity, and their detoxification at the individual and colony-levels. [NP305, Component 2, Problem Statements 2A and 2B] (Anderson, Palmer-Young) Sub-objective 3A: Determine the effect of plant secondary metabolites on microbial health of workers. (Palmer-Young, Anderson) Hypothesis 3A: Hindgut microbial communities and/or host health metrics are unaffected by plant secondary metabolites in the diet. Sub-objective 3B: Determine the effect of recalcitrant polysaccharides on host-microbial function in workers. (Anderson) Hypothesis 3B: Hindgut microbial communities and/or host health metrics are unaffected by the addition of recalcitrant polysaccharides in the diet.