Manure application improves soil productivity but also spreads microorganisms, some of which can be of clinical relevance. The ability of manure to spread common human pathogens has been widely studied but we lack understanding on whether it also disseminates opportunistic pathogens like Acinetobacter and other non-fermenting Gram-negative bacteria (NFGNB). We designed a microcosm experiment simulating the application of fresh manure to soil to analyse the effects on soil microbial communities (and vice versa), focusing on Acinetobacter and other NFGNB. We conducted two independent experiments with fresh cattle manure from a dairy farm and two pasture soils from different organic farms. We sampled the microcosms on days 2, 7, 14, 28 and 84, and characterized the microbial communities through sequencing of 16S rRNA amplicons from i) total communities and ii) those cultured on CHROMagar Acinetobacter (i.e., selective for NFGNB) after 24-h growth. Manure altered the community composition of soil microorganisms whereas the reverse effects were weaker, showing a transition to an environmentally structured community. Acinetobacter species increased their relative abundance in manure and soil under manure on day 2, especially in soils previously exposed to γ-irradiation to reduce the load of native microorganisms. Although manure spread most Acinetobacter phylotypes in the soil, it also stimulated a few from the soil that became occasionally abundant in manure. This study demonstrates that Acinetobacter species may dominate in soil and manure for a short time after deposition, and highlights their high responsiveness and competitiveness to changes likely associated with an increase in labile resources.

施肥提高了土壤生产力，但也传播了微生物，其中一些可能具有临床意义。粪便传播常见人类病原体的能力已被广泛研究，但我们对它是否也传播机会性病原体如不动杆菌和其他非发酵革兰氏阴性菌 (NFGNB) 缺乏了解。我们设计了一个微观实验，模拟将新鲜肥料施用于土壤，以分析对土壤微生物群落的影响（反之亦然），重点是不动杆菌和其他 NFGNB。我们对来自奶牛场的新鲜牛粪和来自不同有机农场的两种牧场土壤进行了两次独立实验。我们在第 2、7、14、28 和 84 天对微观世界进行了采样，并通过对来自 i) 总群落和 ii) 在 CHROMagar 不动杆菌 (即 NFGNB 选择性) 上培养的 16S rRNA 扩增子进行测序来表征微生物群落。 h 增长。粪便改变了土壤微生物的群落组成，而反作用较弱，表明向环境结构群落的过渡。在第 2 天，不动杆菌在粪肥和粪肥土壤中的相对丰度增加，特别是在先前暴露于 γ 辐射以减少原生微生物负荷的土壤中。虽然粪便传播最多不动杆菌种系在土壤中，它也刺激了一些从土壤中变得偶尔丰富的粪便。这项研究表明，不动杆菌属物种可能在沉积后短时间内在土壤和粪便中占主导地位，并强调了它们对可能与不稳定资源增加相关的变化的高度响应性和竞争力。