Detoxification functionality of lactic acid bacteria

在我们目前的NSERC发现奖助金中显示乳酸菌可以对重金属、黄曲霉毒素和杀虫剂进行解毒，现在我们希望确定减轻杀虫剂影响的机制。这对于对抗蜜蜂群体崩溃紊乱很重要。没有什么比这些传粉者的损失更危及全球粮食供应了。我们的初步发现表明，常用的杀虫剂会削弱昆虫的免疫力，使它们更容易受到各种病原体的影响。 假设 我们推测，乳杆菌属的成员具有解毒危害蜜蜂和其他生命形式的杀虫剂的能力。 长期目标 这项研究计划的长期目标是增进我们对一种重要细菌属的了解，这种细菌属在食品和补充剂中的安全使用历史悠久，并开发出对抗环境化学物质和提高传粉者存活率的属性。 研究目标 1.描述乳酸菌如何减轻农药的免疫抑制作用和对病原体的敏感性 2.测定乳酸菌对与农业有关的外来生物解毒的功能能力。 方法论途径 我们将使用黑腹果蝇作为蜜蜂的一个成熟和强大的预测模型，以确定乳杆菌如何影响先天免疫(在广泛的分类范围内高度保守)对农药和/或病原体的协同调节反应，因为它们主要适用于蜜蜂，但也适用于其他宿主。我们将利用我们的RNAi介导的DUOX和IMD途径的下调和过表达突变株，并将这些敲除与基于qPCR的IMD和DUOX途径相关基因表达和免疫荧光染色相关免疫蛋白的检测相结合。我们会让苍蝇接触不同类别的杀虫剂：新烟碱、有机磷、氨基甲酸酯、草甘膦、乙酰甲胺磷、氯氟氰菊酯、恶霉灵、四康唑等。鼠李糖乳杆菌GR-1、植物乳杆菌Lp39、昆基乳杆菌BR1、路氏乳杆菌RC-14、鼠李乳杆菌GG和来自非洲蜜蜂的菌株将被用来对抗杀虫剂，并确定它们是否真的能降解这些化学物质。我们将比较健康蜂箱和感染P.幼虫、梅利索球菌、API、N.ceranae、Ascosphaera apis、Crithdia ombi或Varroa destructor的蜂箱中的微生物群，这些病原体将在体外检测乳杆菌对它们的抑制能力。果蝇模型还将被用来测试各种乳杆菌调节解毒途径的能力。 意义 最终结果将是了解乳杆菌菌株如何通过降解乳杆菌来对抗最广泛使用的杀虫剂，以及通过调节昆虫免疫反应、微生物群的弹性和对抗关键的蜜蜂病原体。

Having shown in our current NSERC Discovery Grant that lactobacilli can perform detoxification of heavy metals, aflatoxins and pesticides, we now wish to identify the mechanisms involved in mitigating the pesticide effects. This is important to counter colony collapse disorder in honey bees. Nothing endangers the global food supply more than the loss of these pollinators. Our preliminary findings suggest that commonly used pesticides impair insect immunity making them more susceptible to a variety of pathogens. Hypothesis We hypothesize that members of the genus Lactobacillus harbor the ability to detoxify pesticides that endanger honey bees and other life forms. Long term goals The long-term goal of this research program is to advance our knowledge of an important bacterial genus with a long history of safe use in foods and supplements, and to exploit attributes that counter environmental chemicals and improve the survival of pollinators. Research objectives 1. 1. Characterize how lactobacilli mitigates the immunosuppressive effects of pesticides and susceptibility to pathogens 2. Determine the functional capacity of lactobacilli to detoxify agriculturally-relevant xenobiotics. Methodological approach We will use Drosophila melanogaster as a well-established and strongly predictive model of the honey bee to determine how lactobacilli affect the co-modulatory response of innate immunity (highly conserved across broad taxonomic range) towards pesticides and/or pathogens as they apply primarily to honeybees, but also other hosts. We will utilize our stocks of RNAi-mediated knockdown and overexpression mutants of the DUOX and Imd pathways, and couple these knockouts with qPCR-based measurement of Imd and DUOX pathway-related gene expression and immunofluorescent stain relevant immune proteins. We will expose flies to different classes of pesticides: neonicotinoids, organophosphates, carbamates, Roundup (glyphosate), acephate, -cyhalothrin, oxamyl, tetraconazole administered at different concentrations. Lactobacillus rhamnosus GR-1, L. plantarum Lp39, L. kunkeei BR1, L. reuteri RC-14, L. rhamnosus GG and strains from African bees will be used to counter the pesticides and determine if they can actually degrade the chemicals. We will compare the microbiota in bees from healthy hives to that of hives infected with P. larvae, Melissococcus plutonius, N. apis, N. ceranae, Ascosphaera apis, Crithidia bombi or Varroa destructor, pathogens that will be examined in vitro for the ability of the lactobacilli to inhibit them. The Drosophila model will also be used to test various lactobacilli for their ability to modulate detoxification pathways. Significance The net result will be to develop an understanding of how lactobacilli strains can counter the most widely used pesticides through their degradation, and by modulation of insect immune responses, microbiota resilience, and countering key honey bee pathogens.