摘要

      鉴于畜禽粪便中存在抗生素和抗药性细菌，重要的是要确定土地施用肥料衍生土壤改良剂潜在传播抗药性的关键途径。这项田间规模研究的目的是确定不同类型的土壤改良剂（头孢匹林和皮尔霉素处理过的牛的生粪肥、抗生素处理过的或无抗生素的牛的堆肥，或仅使用化肥）和作物类型（莴苣或萝卜）通过六次自然发生的风暴径流运输两种抗生素抗性基因（ARGs；1和）。同时对径流中的沉积物和粪便指示细菌（FIB；和肠球菌）进行定量，可以与传统的农业水质指标进行比较，后者可能是ARG存在的驱动因素。风暴特征（总降雨量、风暴持续时间等）显著影响了FIB浓度（双向方差分析，<0.05），尽管个别风暴事件（Kruskal Wallis，<0.05）和植被覆盖都影响了沉积物水平。堆肥和原肥改良后的地块在初期暴雨（至少在初植后8周）的径流中均显著高于纯肥料或未改良的荒地。经抗生素处理的堆肥处理的地块与未经抗生素处理的奶牛相比，径流中的1或B水平没有显著差异。我们的研究结果表明，施用有机肥改良剂的农田在径流中释放出更多的这两种“指示”ARGs，特别是在生长季节的早期，而且堆肥并没有减少ARGs在径流中的负荷效应。

       Given the presence of antibiotics and resistant bacteria in livestock manures, it is important to identify the key pathways by which land-applied manure-derived soil amendments potentially spread resistance. The goal of this field-scale study was to identify the effects of different types of soil amendments (raw manure from cows treated with cephapirin and pirlimycin, compost from antibiotic-treated or antibiotic-free cows, or chemical fertilizer only) and crop type (lettuce [ L.] or radish [ L.]) on the transport of two antibiotic resistance genes (ARGs; 1 and ) via storm runoff from six naturally occurring storms. Concurrent quantification of sediment and fecal indicator bacteria (FIB; and enterococci) in runoff permitted comparison to traditional agricultural water quality targets that may be driving factors of ARG presence. Storm characteristics (total rainfall volume, storm duration, etc.) significantly influenced FIB concentration (two-way ANOVA, < 0.05), although both effects from individual storm events (Kruskal-Wallis, < 0.05) and vegetative cover influenced sediment levels. Composted and raw manure-amended plots both yielded significantly higher 1 and B levels in runoff for early storms, at least 8 wk following initial planting, relative to fertilizer-only or unamended barren plots. There was no significant difference between 1 or B levels in runoff from plots treated with compost derived from antibiotic-treated versus antibiotic-free dairy cattle. Our findings indicate that agricultural fields receiving manure-derived amendments release higher quantities of these two "indicator" ARGs in runoff, particularly during the early stages of the growing season, and that composting did not reduce effects of ARG loading in runoff.

        https://acsess.onlinelibrary.wiley.com/doi/abs/10.2134/jeq2018.12.0441