Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, the Netherlands.
Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, the Netherlands.
Sci Total Environ. 2020 Oct 1;737:139563. doi: 10.1016/j.scitotenv.2020.139563. Epub 2020 May 20.
Manure application can spread antimicrobial resistance (AMR) from manure to soil and surface water. This study evaluated the role of the soil texture on the dynamics of antimicrobial resistance genes (ARGs) in soils and surrounding surface waters. Six dairy farms with distinct soil textures (clay, sand, and peat) were sampled at different time points after the application of manure, and three representative ARGs sul1, erm(B), and tet(W) were quantified with qPCR. Manuring initially increased levels of erm(B) by 1.5 ± 0.5 log copies/kg of soil and tet(W) by 0.8 ± 0.4 log copies/kg across soil textures, after which levels gradually declined. In surface waters from clay environments, regardless of the ARG, the gene levels initially increased by 2.6 ± 1.6 log copies/L, after which levels gradually declined. The gene decay in soils was strongly dependent on the type of ARG (erm(B) < tet(W) < sul1; half-lives of 7, 11, and 75 days, respectively), while in water, the decay was primarily dependent on the soil texture adjacent to the sampled surface water (clay < peat < sand; half-lives of 2, 6, and 10 days, respectively). Finally, recovery of ARG levels was predicted after 29-42 days. The results thus showed that there was not a complete restoration of ARGs in soils between rounds of manure application. In conclusion, this study demonstrates that rather than showing similar dynamics of decay, factors such as the type of ARG and soil texture drive the ARG persistence in the environment.
粪便施入会将抗微生物药物耐药性（AMR）从粪便传播到土壤和地表水。本研究评估了土壤质地在土壤和周围地表水的抗微生物药物耐药基因（ARGs）动态中的作用。在粪便施用后不同时间点，从 6 个具有不同土壤质地（粘土、沙子和泥炭）的奶牛场进行采样，并使用 qPCR 定量 3 个代表性的 ARGs（sul1、erm(B) 和 tet(W)）。最初，在所有土壤质地中，erm(B)的水平增加了 1.5±0.5 log 拷贝/千克土壤，tet(W)的水平增加了 0.8±0.4 log 拷贝/千克土壤，此后水平逐渐下降。在粘土环境的地表水，无论 ARG 如何，基因水平最初增加了 2.6±1.6 log 拷贝/L，此后水平逐渐下降。土壤中基因的衰减强烈取决于 ARG 的类型（erm(B)<tet(W)<sul1；半衰期分别为 7、11 和 75 天），而在水中，衰减主要取决于与采样地表水相邻的土壤质地（粘土<泥炭<沙子；半衰期分别为 2、6 和 10 天）。最后，预测在 29-42 天后 ARG 水平会恢复。因此，结果表明，在两轮粪便施用之间，土壤中的 ARG 并没有完全恢复。总之，本研究表明，决定 ARG 在环境中持久性的因素不是 ARG 的衰减动力学相似，而是 ARG 的类型和土壤质地等因素。
