Rowland Institute at Harvard University, Cambridge, MA 02142, USA.
Department of Chemistry, Villanova University, Villanova, PA 19085, USA.
Cell Host Microbe. 2020 Feb 12;27(2):213-224.e7. doi: 10.1016/j.chom.2020.01.009. Epub 2020 Feb 4.
The gut is a first point of contact with ingested xenobiotics, where chemicals are metabolized directly by the host or microbiota. Atrazine is a widely used pesticide, but the role of the microbiome metabolism of this xenobiotic and the impact on host responses is unclear. We exposed successive generations of the wasp Nasonia vitripennis to subtoxic levels of atrazine and observed changes in the structure and function of the gut microbiome that conveyed atrazine resistance. This microbiome-mediated resistance was maternally inherited and increased over successive generations, while also heightening the rate of host genome selection. The rare gut bacteria Serratia marcescens and Pseudomonas protegens contributed to atrazine metabolism. Both of these bacteria contain genes that are linked to atrazine degradation and were sufficient to confer resistance in experimental wasp populations. Thus, pesticide exposure causes functional, inherited changes in the microbiome that should be considered when assessing xenobiotic exposure and as potential countermeasures to toxicity.
肠道是摄入的外源化学物质的第一个接触点，其中的化学物质可被宿主或微生物群直接代谢。阿特拉津是一种广泛使用的农药，但这种外源化学物质的微生物群代谢及其对宿主反应的影响尚不清楚。我们使黄蜂 Nasonia vitripennis 的连续几代暴露于亚毒性水平的阿特拉津下，并观察到肠道微生物组结构和功能的变化，这些变化赋予了阿特拉津抗性。这种由微生物组介导的抗性是母系遗传的，并随着世代的增加而增加，同时也提高了宿主基因组选择的速度。稀有肠道细菌粘质沙雷氏菌和恶臭假单胞菌有助于阿特拉津的代谢。这两种细菌都含有与阿特拉津降解相关的基因，足以在实验性黄蜂种群中赋予抗性。因此，农药暴露会导致微生物组发生功能性、遗传性变化，在评估外源化学物质暴露和作为毒性的潜在对策时应予以考虑。
