Abundance of six tetracycline resistance genes in wastewater lagoons at cattle feedlots with different antibiotic use strategies
Abundance of six tetracycline resistance genes in wastewater lagoons at cattle feedlots with different antibiotic use strategies
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DOI：
10.1111/j.1462-2920.2006.01123.x
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发表时间：
2007-01-01
影响因子：
5.1
通讯作者：
Graham, David W.
中科院分区：
文献类型：
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作者：
Peak, Nicholas;Knapp, Charles W.;Graham, David W.
为了评价饲养场作业对下游表层水中四环素抗性基因的影响，对污水池中6种四环素抗性基因tet(O)、tet(Q)、tet(W)、tet(M)、tet(B)和tet(L)随时间的变化进行了定量研究。对美国中西部五个养牛场的八个泻湖进行了为期6个月的监测。抗性和16S-rRNA基因丰度用实时荧光聚合酶链式反应进行了量化，并随着时间的推移监测了物理化学泻湖条件、四环素水平和其他因素(如饲养场大小和天气条件)。根据每个地点的抗生素使用实践对泻湖进行分类，并指定为不使用、混合使用或高使用以供比较。高用途泻湖的抗性基因检测水平(tet(R)；2.8×10(6)拷贝ml(-1))显著高于不使用泻湖(5.1x10(3)拷贝ml(-1)；P<0.01)和混用泻湖(7.3x10(5)拷贝ml(-1)；P=0.076)。对汇集数据的二元相关分析(n=54)证实，Tet(R)水平与每个泻湖的饲料场面积(r=0.67，P<；0.01)和细菌总16S-rRNA基因水平(r=0.51，P<；0.01)显著相关，这两个指标都是大型CAFO的特征。Tet(M)是最常见的检测基因，无论是绝对数量还是归一化到16S-rRNA基因水平，尽管混合使用和高度利用的泻湖中tet(O)、tet(Q)和tet(W)的水平也很高。最后，抗性基因水平具有很强的季节性，秋季的丰度是夏季的10-100倍。结果表明，抗生素的使用策略强烈地影响了相关泻湖中抗性基因的丰度和季节分布，这对水质和饲养场管理实践具有重要意义。
The abundance of six tetracycline resistance genes tet(O), tet(Q), tet(W), tet(M), tet(B) and tet(L), were quantified over time in wastewater lagoons at concentrated animal feeding operations (CAFO) to assess how feedlot operation affects resistance genes in downstream surface waters. Eight lagoons at five cattle feedlots in the Midwestern United States were monitored for 6 months. Resistance and 16S-rRNA gene abundances were quantified using real-time PCR, and physicochemical lagoon conditions, tetracycline levels, and other factors (e.g. feedlot size and weather conditions) were monitored over time. Lagoons were sorted according to antibiotic use practice at each site, and designated as 'no-use', 'mixed-use' or 'high-use' for comparison. High-use lagoons had significantly higher detected resistance gene levels (tet(R); 2.8 x 10(6) copies ml(-1)) relative to no-use lagoons (5.1 x 10(3) copies ml(-1); P < 0.01) and mixed-use lagoons (7.3 x 10(5) copies ml(-1); P = 0.076). Bivariate correlation analysis on pooled data (n = 54) confirmed that tet(R) level strongly correlated with feedlot area (r = 0.67, P < 0.01) and 'total' bacterial 16S-rRNA gene level in each lagoon (r = 0.51, P < 0.01), which are both characteristic of large CAFOs. tet(M) was the most commonly detected gene, both in absolute number and normalized to 16S-rRNA gene level, although tet(O), tet(Q) and tet(W) levels were also high in the mixed and high-use lagoons. Finally, resistance gene levels were highly seasonal with abundances being 10-100 times greater in the autumn versus the summer. Results show that antibiotic use strategy strongly affects both the abundance and seasonal distribution of resistance genes in associated lagoons, which has implications on water quality and feedlot management practices.