Quantitative variation in the core bacterial community associated with honey bees from <i>Varroa-</i>infested colonies

Infestations of the ectoparasitic mite <i>Varroa destructor</i> cause significant honey bee colony weakening, due to both host-feeding and virus transmission effects. In addition to the natural (i.e., behavioral) and innate (i.e., cellular and humoral response) mechanisms of defense against pathogens and parasites, contribution to maintain good colony health may derive from the resident microbial community. The present study investigated variation in immune-related gene expression levels and in the relative abundance of representative bacterial taxa of the core honey bee microbiota in colonies infested by <i>Varroa</i> mites in comparison with honey bees from non-infested colonies. Significant changes in the target bacterial taxa (Gammaproteobacteria, Betaproteobacteria, <i>Lactobacillus</i> spp., <i>Bifidobacterium</i> spp., <i>Brevibacillus laterosporus</i>) were detected in immune-suppressed adults emerging from <i>Varroa</i>-infested colonies. Insect stages randomly sampled from infested and non-infested hives were characterized by high variability. Emerging adults bearing sucking <i>Varroa</i> mites on their body showed a considerably higher deformed wing virus titer and a greater immune gene downregulation compared with adults without mites. Further, the abundance of the overall bacterial community and of specific bacterial taxa increased significantly in parasitized adults. A possible compensation mechanism involving the core bacterial community in <i>Varroa</i>-infested hives is discussed.

体外寄生螨狄斯瓦螨（Varroa destructor）可通过寄主演食与病毒传播双重途径，对蜜蜂蜂群造成显著的弱化效应。除宿主针对病原体与寄生虫的天然（行为）防御及先天（细胞与体液免疫）应答机制外，蜂群的健康维持还可能得益于其常驻微生物群落。本研究对比分析了狄斯瓦螨侵染蜂群与未侵染蜂群的蜜蜂，其免疫相关基因的表达水平差异，以及蜜蜂核心菌群中代表性细菌类群的相对丰度变化。研究发现，从狄斯瓦螨侵染蜂群中羽化的免疫抑制成虫体内，目标细菌类群（γ-变形菌纲、β-变形菌纲、乳杆菌属（Lactobacillus）、双歧杆菌属（Bifidobacterium）、侧孢短芽孢杆菌（Brevibacillus laterosporus））的丰度发生了显著改变。从侵染与未侵染蜂箱中随机采样的虫态呈现较高的变异程度；体表携带吸食性狄斯瓦螨的羽化成虫，相较于无螨成虫，其翅变形病毒（Deformed Wing Virus）滴度显著更高，免疫基因下调程度也更为显著。此外，被寄生成虫的整体细菌群落及特定细菌类群的丰度均出现显著上升。本文最后探讨了狄斯瓦螨侵染蜂群中核心菌群可能参与的补偿机制。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于Varroa螨虫侵染对蜜蜂核心细菌群落的影响，通过分析免疫基因表达和细菌类群（如Gammaproteobacteria、Lactobacillus spp.等）的定量变化，揭示了侵染导致蜜蜂免疫抑制和细菌群落丰度增加的关联。数据集来自一项2019年的研究，旨在探讨蜜蜂健康与微生物群落之间的相互作用，为理解社会免疫机制提供数据支持。