Stably transmitted defined microbial community in honeybees preserves Hafnia alvei inhibition by regulating the immune system

Abstract

The gut microbiota of honeybees is highly diverse at the strain level and essential to the proper function and development of the host. Interactions between the host and its gut microbiota, such as specific microbes regulating the innate immune system, protect the host against pathogen infections. However, little is known about the capacity of these strains deposited in one colony to inhibit pathogens. In this study, we assembled a defined microbial community based on phylogeny analysis, the ‘Core-20’ community, consisting of 20 strains isolated from the honeybee intestine. The Core-20 community could trigger the upregulation of immune gene expressions and reduce Hafnia alvei prevalence, indicating immune priming underlies the microbial protective effect. Functions related to carbohydrate utilization and the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS systems) are represented in genomic analysis of the defined community, which might be involved in manipulating immune responses. Additionally, we found that the defined Core-20 community is able to colonize the honeybee gut stably through passages. In conclusion, our findings highlight that the synthetic gut microbiota could offer protection by regulating the host immune system, suggesting that the strain collection can yield insights into host-microbiota interactions and provide solutions to protect honeybees from pathogen infections.

Glyphosate Effects on Growth and Biofilm Formation in Bee Gut Symbionts and Diverse Associated Bacteria

“…This shows that members of the bee core microbiota can robustly colonize the bee gut in the absence of other community members. Furthermore, defined communities consisting of core member strains as well as gut homogenate treatments allowed typical bee gut colonization by core members, as observed in other studies (49)(50)(51). Exceptions included one cup cage from Snodgrassella-treated bees, in which considerable Serratia reads were detected, suggesting potential cross-contamination, and all Serratia-treated bees, in which reads were detected for core and non-core bee gut Lactobacillus species and others (Figure 1C).…”

“…Several previous studies have colonized newly emerged honey bees, which lack their native microbiota, with single or a set of specific strains of core microbiota members to investigate colonization patterns, their roles in the gut, and host health. Most of these studies confirm colonization status by plating gut homogenates on selective media or by extracting DNA from bee guts and performing quantitative PCR (qPCR) with universal or species-specific 16S rRNA primers (33,34,(36)(37)(38)(39)(40)(50)(51)(52)(53)(54)(55)(56). While valid for most purposes, these techniques may not detect potential contamination.…”