Université Laval, Institut de Biologie Intégrative et des Systèmes (IBIS), Québec, Canada.
Département de Biologie, Université Laval, Québec, Canada.
Microbiol Spectr. 2024 Oct 3;12(10):e0057824. doi: 10.1128/spectrum.00578-24. Epub 2024 Aug 27.
Pesticides are causing honeybee mortality worldwide. Research carried out on honeybees indicates that application of pesticides has a significant impact on the core gut community, which ultimately leads to an increase in the growth of harmful pathogens. Disturbances caused by pesticides also affect the way bacterial members interact, which results in gut microbial dysbiosis. Administration of beneficial microbes has been previously demonstrated to be effective in treating or preventing disease in honeybees. The objective of this study was to measure under conditions the ability of two bacterial strains (the sp. and sp.) isolated from honeybee gut to improve survival and mitigate gut microbiota dysbiosis in honeybees exposed to a sublethal clothianidin dose (0.1 ppb). Both gut bacterial strains were selected for their ability to degrade clothianidin regardless of their host-microbe interaction characteristics (e.g., beneficial, neutral, or harmful). To this end, we conducted cage trials on 4- to 6-day-old newly emerging honeybees. During microbial administration, we jointly monitored the taxonomic distribution and activity level of bacterial symbionts quantifying 16S rRNA transcripts. First, curative administration of the sp. strain significantly improved the survival of clothianidin-exposed honeybees compared to sugar control bees (i.e., supplemented with sugar [1:1]). Second, curative administration of the sp. strain significantly mitigated the clothianidin-induced dysbiosis observed in the midgut structural network, but without improving survival.
The present work suggests that administration of bacterial strains isolated from honeybee gut may promote recovery of gut microbiota homeostasis after prolonged clothianidin exposure, while improving survival. This study highlights that gut bacterial strains hold promise for developing efficient microbial formulations to mitigate environmental pesticide exposure in honeybee colonies.
全世界范围内，杀虫剂正导致蜜蜂死亡。对蜜蜂进行的研究表明，杀虫剂的使用对核心肠道群落有重大影响，这最终导致有害病原体的生长增加。杀虫剂造成的干扰也会影响细菌成员之间的相互作用方式，从而导致肠道微生物失调。先前已经证明，有益微生物的施用在治疗或预防蜜蜂疾病方面是有效的。本研究的目的是在条件下测量从蜜蜂肠道中分离出的两种细菌菌株（ sp. 和 sp. ）提高对亚致死剂量（0.1 ppb）氯虫苯甲酰胺暴露的蜜蜂的生存能力并减轻其肠道微生物失调的能力。这两种肠道细菌菌株都因其能够降解氯虫苯甲酰胺而被选择，而不考虑其宿主-微生物相互作用特征（例如有益、中性或有害）。为此，我们在 4 至 6 天大的新出现的蜜蜂上进行了笼式试验。在微生物施用期间，我们共同监测了细菌共生体的分类分布和活性水平，定量了 16S rRNA 转录物。首先，与糖对照蜜蜂（即补充糖[1:1]）相比， sp. 菌株的治疗性施用显著提高了暴露于氯虫苯甲酰胺的蜜蜂的存活率。其次， sp. 菌株的治疗性施用显著减轻了在中肠结构网络中观察到的氯虫苯甲酰胺诱导的失调，但没有提高存活率。
本工作表明，从蜜蜂肠道中分离出的细菌菌株的施用可能会促进在长时间暴露于氯虫苯甲酰胺后肠道微生物群稳态的恢复，同时提高存活率。本研究强调了肠道细菌菌株在开发有效微生物配方以减轻蜜蜂群体中环境农药暴露方面的潜力。
