Composting rapidly reduces levels of extractable oxytetracycline in manure from therapeutically treated beef calves
Composting rapidly reduces levels of extractable oxytetracycline in manure from therapeutically treated beef calves
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DOI：
10.1016/j.biortech.2005.10.041
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发表时间：
2007-01-01
影响因子：
11.4
通讯作者：
Foster, Gregory D.
中科院分区：
文献类型：
--
作者：
Arikan, Osman A.;Sikora, Lawrence J.;Foster, Gregory D.
土霉素（OTC）是一种用于畜牧生产的广谱抗生素。OTC的广泛使用和相对持久性可能会促进耐药细菌的发展。本研究的目的是确定堆肥是否会大大降低药物动物粪便中OTC的浓度。研究了OTC对堆肥的影响。以22 mg/kg/天的OTC给药5天。大约23%喂给小牛的非处方药在粪便中被回收。将在用药前后采集的犊牛粪便样本与秸秆和木屑混合，等量的后续混合物在实验室堆肥机中处理35天。此外，等份含OTC的混合物在25℃下孵育或消毒后再在25℃下孵育。OTC的存在似乎不影响堆肥过程。在堆肥的前6天，堆肥混合物中可提取的OTC水平从115 +/- 8 μ g/g干重下降到6 +/- 1 μ g/g干重以下（减少95%）。相比之下，室温孵育和灭菌混合物中可提取的OTC含量在37天和35天后分别仅下降了12-25%。最终堆肥混合物中总异养细菌和抗otc细菌的水平分别比堆肥前混合物中的水平高30倍和低10倍。尽管在堆肥过程中OTC消失的原因尚不清楚，但成品堆肥中OTC敏感细菌的优势和OTC耐药细菌的减少表明OTC残留物已变得生物无活性或不可用。(c) 2005 Elsevier Ltd版权所有。
Oxytetracychne (OTC) is a broad-spectrum antibiotic used in livestock production. The widespread use and relative persistence of OTC may encourage development of antibiotic-resistant bacteria. The objective of this study was to determine whether composting would substantially reduce the concentration of OTC found in manure from medicated animals. The effect of OTC on composting was also investigated. Five beef calves were medicated for 5 days with 22 mg/kg/day of OTC. Approximately 23% of the OTC fed to the calves was recovered in the manure. Manure samples collected from calves prior to and after medication were mixed with straw and woodchips, and aliquots of the subsequent mixtures were treated in laboratory composters for 35 days. In addition, aliquots of the OTC-containing mixture were incubated at 25 degrees C or sterilized followed by incubation at 25 degrees C. The presence of OTC did not appear to affect composting processes. Within the first six days of composting, levels of extractable OTC in the compost mixture decreased from 115 +/- 8 mu g/g dry weight to less than 6 +/- 1 mu g/g dry weight (a 95% reduction). In contrast, levels of extractable OTC in room temperature incubated and sterilized mixtures decreased only 12-25% after 37 and 35 days, respectively. Levels of total heterotrophic bacteria and OTC-resistant bacteria in the finished compost mixture were roughly 30-fold higher and 10-fold lower, respectively, than levels in the mixture prior to composting. Although the basis of the OTC disappearance during composting is not known, the preponderence of OTC-sensitive bacteria and the decrease of OTC-resistant bacteria in the finished compost suggests that OTC residues have been rendered biologically inactive or unavailable. (c) 2005 Elsevier Ltd. All rights reserved.