Diverse and abundant antibiotic resistance genes in Chinese swine farms
Diverse and abundant antibiotic resistance genes in Chinese swine farms
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DOI：
10.1073/pnas.1222743110
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发表时间：
2013-02-26
影响因子：
11.1
通讯作者：
Tiedje, James M.
中科院分区：
文献类型：
--
作者：
Zhu, Yong-Guan;Johnson, Timothy A.;Tiedje, James M.
抗生素耐药基因（ARGs）是一种新兴污染物，对全球人类健康构成潜在风险。集约化畜牧业被认为是ARGs环境负担增加的主要原因。尽管中国使用了大量抗生素，但有关与动物养殖场相关的相应ARGs的信息很少。我们评估了中国三个大型（每年10000头）商业养猪场粪便处理到土地处理的三个阶段ARGs的类型和浓度。这些农场使用的饲料或治疗用抗生素包括除万古霉素以外的所有主要种类的抗生素。高容量定量PCR阵列在所有农场样本中检测到149个独特的抗性基因，与各自的无抗生素粪肥或土壤对照相比，前63个ARGs富集192倍（中位数）至28,000倍（最大值）。作为饲料添加剂使用的抗生素和重金属在粪便中含量升高，表明可能存在抗性性状的共选择。由于转座子特异性的ARGs， ARGs水平转移的可能性与转座酶的富集有关——前6个等位基因在粪便中富集189倍（中位数）至9万倍——以及ARG与转座酶丰度之间的高相关性（r(2) = 0.96）。此外，ARGs的丰度与抗生素和金属浓度直接相关，表明它们在抗性基因选择中的重要性。农场样本中多样、丰富且可能移动的ARGs表明，未经监测的抗生素和金属使用正在导致ARGs的出现和释放到环境中。
Antibiotic resistance genes (ARGs) are emerging contaminants posing a potential worldwide human health risk. Intensive animal husbandry is believed to be a major contributor to the increased environmental burden of ARGs. Despite the volume of antibiotics used in China, little information is available regarding the corresponding ARGs associated with animal farms. We assessed type and concentrations of ARGs at three stages of manure processing to land disposal at three large-scale (10,000 animals per year) commercial swine farms in China. In-feed or therapeutic antibiotics used on these farms include all major classes of antibiotics except vancomycins. High-capacity quantitative PCR arrays detected 149 unique resistance genes among all of the farm samples, the top 63 ARGs being enriched 192-fold (median) up to 28,000-fold (maximum) compared with their respective antibiotic-free manure or soil controls. Antibiotics and heavy metals used as feed supplements were elevated in the manures, suggesting the potential for coselection of resistance traits. The potential for horizontal transfer of ARGs because of transposon-specific ARGs is implicated by the enrichment of transposases-the top six alleles being enriched 189-fold (median) up to 90,000-fold in manure-as well as the high correlation (r(2) = 0.96) between ARG and transposase abundance. In addition, abundance of ARGs correlated directly with antibiotic and metal concentrations, indicating their importance in selection of resistance genes. Diverse, abundant, and potentially mobile ARGs in farm samples suggest that unmonitored use of antibiotics and metals is causing the emergence and release of ARGs to the environment.