Zhang Yu-Jing, Hu Hang-Wei, Gou Min, Wang Jun-Tao, Chen Deli, He Ji-Zheng
Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia.
Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia.
Environ Pollut. 2017 Dec;231(Pt 2):1621-1632. doi: 10.1016/j.envpol.2017.09.074. Epub 2017 Sep 28.
Land application of animal manure is a common agricultural practice potentially leading to dispersal and propagation of antibiotic resistance genes (ARGs) in environmental settings. However, the fate of resistome in agro-ecosystems over time following application of different manure sources has never been compared systematically. Here, soil microcosm incubation was conducted to compare effects of poultry, cattle and swine manures spiked with or without the antibiotic tylosin on the temporal changes of soil ARGs. The high-throughput quantitative PCR detected a total of 185 unique ARGs, with Macrolide-Lincosamide-Streptogramin B resistance as the most frequently encountered ARG type. The diversity and abundance of ARGs significantly increased following application of manure and manure spiked with tylosin, with more pronounced effects observed in the swine and poultry manure treatments than in the cattle manure treatment. The level of antibiotic resistance gradually decreased over time in all manured soils but was still significantly higher in the soils treated with swine and poultry manures than in the untreated soils after 130 days' incubation. Tylosin-amended soils consistently showed higher abundances of ARGs than soils treated with manure only, suggesting a strong selection pressure of antibiotic-spiked manure on soil ARGs. The relative abundance of ARGs had significantly positive correlations with integrase and transposase genes, indicative of horizontal transfer potential of ARGs in manure and tylosin treated soils. Our findings provide evidence that application of swine and poultry manures might enrich more soil ARGs than cattle manure, which necessitates the appropriate treatment of raw animal manures prior to land application to minimise the spread of environmental ARGs.
在农业中，将动物粪便施用于土地是一种常见的做法，但这可能会导致抗生素抗性基因（ARGs）在环境中扩散和传播。然而，在施用不同粪便来源后，农业生态系统中抗性组随时间的变化情况从未被系统地比较过。在此，进行了土壤微观培养实验，以比较添加或不添加抗生素泰乐菌素的家禽、牛和猪粪便对土壤ARGs随时间变化的影响。高通量定量PCR共检测到185种独特的ARGs，其中大环内酯-林可酰胺-链阳菌素B抗性是最常见的ARGs类型。施用粪便和添加泰乐菌素的粪便后，ARGs的多样性和丰度显著增加，猪和家禽粪便处理组的影响比牛粪处理组更明显。在所有施肥土壤中，抗生素抗性水平随时间逐渐下降，但在培养130天后，猪和家禽粪便处理的土壤中抗生素抗性水平仍显著高于未处理土壤。添加泰乐菌素的土壤中ARGs的丰度始终高于仅施用粪便的土壤，这表明添加抗生素的粪便对土壤ARGs具有很强的选择压力。ARGs的相对丰度与整合酶和转座酶基因呈显著正相关，这表明ARGs在粪便和添加泰乐菌素的土壤中具有水平转移潜力。我们的研究结果表明，施用猪和家禽粪便可能比牛粪使更多的土壤ARGs富集，因此在将动物粪便施用于土地之前，需要对其进行适当处理，以尽量减少环境ARGs的传播。
