Increased Abundance and Transferability of Resistance Genes after Field Application of Manure from Sulfadiazine-Treated Pigs
Increased Abundance and Transferability of Resistance Genes after Field Application of Manure from Sulfadiazine-Treated Pigs
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DOI：
10.1128/aem.03172-12
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发表时间：
2013-03-01
影响因子：
4.4
通讯作者：
Smalla, Kornelia
中科院分区：
文献类型：
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作者：
Jechalke, Sven;Kopmann, Christoph;Smalla, Kornelia
在农业中推广含有抗生素的粪肥被认为会刺激抗生素耐药性在土壤细菌种群中的传播。植物根系通过分泌生长基质影响土壤环境及其微生物区系，可能会大大增强这种效应。在这项研究中，粪便处理磺胺嘧啶（SDZ），这里称为SDZ粪肥，对玉米和草的根际磺胺类药物抗性基因sul1和sul2的丰度和可转移性的影响进行了比较，在散装土壤中的田间试验。在地块，反复接受SDZ肥料，一个显着更高的丰度的两个sul基因检测相比，在地块中的粪便从未经处理的猪。相对于细菌核糖体基因，在根际比在散装土壤中遇到显着较低的丰度的硫基因。然而，与散装土壤的结果相反，在SDZ粪肥处理的根际的sul基因丰度不断偏离控制治疗后6周的一段时间，施肥，这表明在此期间正在进行的抗生素选择。通过捕获土壤中的耐药质粒，分析磺胺类药物耐药性在大肠杆菌中的转移性。从SDZ粪肥处理的散装土壤和玉米和草的根际样品中观察到质粒捕获率增加。超过97%的捕获质粒属于LowGC类型（具有低G + C含量），进一步证明了它们对抗生素耐药性的环境传播的重要贡献。总之，在评估与抗生素耐药性传播相关的风险时，需要考虑散装土壤和根际之间的差异。
Spreading manure containing antibiotics in agriculture is assumed to stimulate the dissemination of antibiotic resistance in soil bacterial populations. Plant roots influencing the soil environment and its microflora by exudation of growth substrates might considerably increase this effect. In this study, the effects of manure from pigs treated with sulfadiazine (SDZ), here called SDZ manure, on the abundance and transferability of sulfonamide resistance genes sul1 and sul2 in the rhizosphere of maize and grass were compared to the effects in bulk soil in a field experiment. In plots that repeatedly received SDZ manure, a significantly higher abundance of both sul genes was detected compared to that in plots where manure from untreated pigs was applied. Significantly lower abundances of sul genes relative to bacterial ribosomal genes were encountered in the rhizosphere than in bulk soil. However, in contrast to results for bulk soil, the sul gene abundance in the SDZ manure-treated rhizosphere constantly deviated from control treatments over a period of 6 weeks after manuring, suggesting ongoing antibiotic selection over this period. Transferability of sulfonamide resistance was analyzed by capturing resistance plasmids from soil communities into Escherichia coli. Increased rates of plasmid capture were observed in samples from SDZ manure-treated bulk soil and the rhizosphere of maize and grass. More than 97% of the captured plasmids belonged to the LowGC type (having low G + C content), giving further evidence for their important contribution to the environmental spread of antibiotic resistance. In conclusion, differences between bulk soil and rhizosphere need to be considered when assessing the risks associated with the spreading of antibiotic resistance.