Influence of food and Nosema ceranae infection on the gut microbiota of Apis cerana workers

Abstract

31Background 32Gut microbiota plays an essential role in bee's health. To elucidate the effect of food 33and Nosema ceranae infection on the gut microbiota of honeybee Apis cerana, we 34 used 16S rRNA sequencing to survey the gut microbiota of honeybee workers fed 35 with sugar water or beebread and inoculated with or without N. ceranae. 36 Results 37The gut microbiota of A. cerana is dominated by Serratia, Snodgrassella, and 38Lactobacillus genera. The overall gut microbiota diversity was significantly 39 differential by food type. The N. ceranae infection significantly affects the gut 40 microbiota only at bees fed with sugar water. Higher abundance of Lactobacillus, 41Gluconacetobacter and Snodgrassella and lower abundance of Serratia were found in 42 bees fed with beebread than with sugar water. N. ceranae infection led to higher 43 abundance of Snodgrassella and lower abundance of Serratia in sugar-fed bees. 44 Imputed bacterial KEGG pathways showed the significant metagenomics functional 45 differences by feeding and N. ceranae infections. Furthermore, A. cerana workers fed 46 with sugar water showed lower N. ceranae spore loads but higher mortality than those 47 fed with beebread. The cumulative mortality was strongly positive correlated 48 (rho=0.61) with the changes of overall microbiota dissimilarities by N. ceranae 49 infection. 50 Conclusions 51Both food and N. ceranae infection significantly affect the gut microbiota in A. 52 cerana workers. Beebread feeding not only provide better nutrition but also help 53 establish a more stabled gut microbiota therefore protect bee in response to N. 54 ceranae infection. 55 56 57 58 59 60 3 / 24 Abstract Importance 61Gut microbiota plays an essential role in bee's health. Scientific evidence suggests the 62 diet and infection can affect the gut microbiota and modulate the gut health, however 63 the interplay between those two factors and bee gut microbiota is not well known. In 64 this study, we used high-throughput sequencing method to monitor the changes of gut 65 microbiota by both food intake and the Nosema ceranae infection. Our result showed 66 that the gut microbiota composition and diversity of Asia Honeybee was significantly 67 associated with both food intake and the N. ceranae infection. More interestingly, 68 bees fed with beebread showed higher microbiota stability and less mortality than 69 those fed with sugar water when infected by N. ceranae . Those data suggest the 70 potential role of beebread, not only providing better nutrition but also helping 71 establish a more stabled gut microbiota to protect bee against N. ceranae infection. 72 73 74

Prospects for probiotics in social bees

“…Nosema also takes advantage of microbial perturbations induced by antibiotics to cause disease in adult workers [54] and can itself perturb the native worker microbiota [74–76]. Many recent probiotic studies in adult honeybees have focused on Nosema and have supplemented caged bees or hives with mixtures of bacteria originating from sources other than the native bee microbiota (see the electronic supplementary material, table S1).…”

Recently introducedWolbachiareduces bacterial species richness and reshapes bacterial community structure inNilaparvata lugens

“…[23][24][25][26] The normal physiological functions in the host are often affected by the extensive changes of bacterial microbiota. Some abiotic factors (e.g., temperature, diet and geographic location) [27][28][29] and biotic factors (e.g., developmental stage, mitochondria and endosymbionts) [29][30][31] can affect the bacterial microbiota in insect hosts. Among them, Wolbachia is an important factor affecting their host's microbial community.…”