University of Bonn, Bonn, Germany.
J Environ Qual. 2012 Jul-Aug;41(4):1275-83. doi: 10.2134/jeq2011.0459.
The environmental risks caused by the use of fluoroquinolone antibiotics in human therapeutics and animal husbandry are associated with their persistence and (bio)accessibility in soil. To assess these aspects, we administered difloxacin to pigs and applied the contaminated manure to soil. We then evaluated the dissipation and sequestration of difloxacin in soil in the absence and presence of plants within a laboratory trial, a mesocosm trial, and a field trial. A sequential extraction yielded antibiotic fractions of differing binding strength. We also assessed the antibiotic's effects on nitrogen turnover in soil (potential nitrification and denitrification). Difloxacin was hardly (bio)accessible and was very persistent under all conditions studied (dissipation half-life in bulk soil, >217 d), rapidly forming nonextractable residues. Although varying environmental conditions did not affect persistence, dissipation was accelerated in soil surrounding plant roots. Effects on nitrogen turnover were limited due to the compound's strong binding and small (bio)accessibility despite its persistence.
氟喹诺酮类抗生素在人类治疗和畜牧业中的使用所造成的环境风险与其在土壤中的持久性和（生物）可及性有关。为了评估这些方面，我们给猪施用了二氟沙星，并将受污染的粪便施用于土壤。然后，我们在实验室试验、中观试验和田间试验中评估了在没有和有植物存在的情况下二氟沙星在土壤中的消解和固定。连续提取得到了结合强度不同的抗生素级分。我们还评估了抗生素对土壤中氮转化（潜在硝化和反硝化）的影响。在所有研究的条件下，二氟沙星几乎（生物）不可及且非常持久（在原状土壤中的消解半衰期>217d），迅速形成不可提取的残留物。尽管环境条件的变化不会影响其持久性，但在植物根周围的土壤中，消解速度加快。尽管其持久性很强，但由于化合物的强结合和较小的（生物）可及性，对氮转化的影响有限。
