Abundance and transferability of antibiotic resistance as related to the fate of sulfadiazine in maize rhizosphere and bulk soil
Abundance and transferability of antibiotic resistance as related to the fate of sulfadiazine in maize rhizosphere and bulk soil
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DOI：
10.1111/j.1574-6941.2012.01458.x
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发表时间：
2013-01-01
影响因子：
4.2
通讯作者：
Smalla, Kornelia
中科院分区：
文献类型：
--
作者：
Kopmann, Christoph;Jechalke, Sven;Smalla, Kornelia
兽用抗生素随粪便进入农田，存在传播抗生素耐药性的风险。通过粪便引入的磺胺嘧啶（SDZ）的命运及其对根际抗性基因水平的影响与散装土壤中的影响进行了比较。玉米植株在施有 SDZ 处理猪（SDZ 处理）或未处理猪（对照）粪便的土壤中生长 9 周。 SDZ 的 CaCl2 提取浓度在根际消散得比在土壤中更快，但 SDZ 在整个过程中仍然可检测到。对于大块土壤，第 14 天和第 63 天的定量 PCR 显示，SDZ 处理中 sul1 和 sul2 相对于 16S rRNA 基因拷贝的丰度高于对照。在第 63 天采样的根际中，SDZ 处理中 sul 基因的相对丰度也显着增加。细菌累积的 SDZ 暴露（直到第 63 天）与 sul1 和 sul2 的对数相对丰度显着相关，因此这些抗性基因在根际的丰度低于在土壤中的丰度。在大肠杆菌中外源捕获的赋予 SDZ 抗性的质粒主要属于 LowGC 组，并且携带对不同类别抗生素的异质抗性负载。
Veterinary antibiotics entering agricultural land with manure pose the risk of spreading antibiotic resistance. The fate of sulfadiazine (SDZ) introduced via manure and its effect on resistance gene levels in the rhizosphere were compared with that in bulk soil. Maize plants were grown for 9 weeks in soil fertilized with manure either from SDZ-treated pigs (SDZ treatment) or from untreated pigs (control). CaCl2-extractable concentrations of SDZ dissipated faster in the rhizosphere than in bulk soil, but SDZ remained detectable over the whole time. For bulk soil, the abundance of sul1 and sul2 relative to 16S rRNA gene copies was higher in the SDZ treatment than in the control, as revealed by quantitative PCR on days 14 and 63. In the rhizosphere, sampled on day 63, the relative sul gene abundances were also significantly increased in the SDZ treatment. The accumulated SDZ exposure (until day 63) of the bacteria significantly correlated with the log relative abundance of sul1 and sul2, so that these resistance genes were less abundant in the rhizosphere than in bulk soil. Plasmids conferring SDZ resistance, which were exogenously captured in Escherichia coli, mainly belonged to the LowGC group and carried a heterogeneous load of resistances to different classes of antibiotics.