摘要
      抗生素耐药性基因（ARGs）正在引起全世界越来越多的关注。许多先前的研究已经调查了水产养殖中ARGs的发生和浓度。然而，ARGs的来源及其与潜在细菌宿主的联系尚未得到探索。本研究通过宏基因组测序，调查了中国南方两种对虾养殖场ARGs的丰度和多样性。总共检测到14种ARG类型。四环素是ARG的主要类型。样品中ARGs的丰度依次为鸭粪>水源>沉积物>虾肠>池水。鸭虾综合养殖场的样本中的ARG含量是虾单一养殖场的1.29–3.81倍（p<0.05）。鸭粪样本中最主要的几种ARG，也是鸭虾综合饲养场虾肠样本中最重要的几种。冗余分析表明，ARGs的丰度和分布形成了三个聚类：鸭粪便、水样、沉积物和虾肠样品。鸭粪中被称为人类致病菌的优势属是ARGs的潜在宿主，在鸭虾综合养殖场的虾肠样本中也占优势。此外，鸭虾综合养殖场虾肠样品中优势属的丰度是虾单一养殖场的1.74–35.07倍（p<0.01）。鸭虾综合饲养场虾肠样本中ARGs和移动遗传元素的丰度分别是虾单一饲养场的3.36和4.94倍，结果表明，鸭粪可能是鸭虾综合养殖场养殖虾中多种和丰富ARGs传播的重要来源，对公众健康构成严重风险。
Abstract
Antibiotic resistance genes (ARGs) are attracting increasing concern worldwide. Many previous studies have investigated the occurrence and concentrations of ARGs in aquaculture. However, the sources of ARGs and the links with their potential bacterial hosts have not yet been explored. This study investigated the abundances and diversity of ARGs in two types of shrimp farms in South China through metagenomic sequencing. In total, 14 ARG types were detected. Tetracycline was the dominant ARG type. The abundances of ARGs in samples decreased in the order of duck feces > water source > sediment > shrimp gut > pond water. The samples from the duck–shrimp integrated farm contained 1.29–3.81-fold more abundant ARGs than those from the shrimp monoculture farm (p < 0.05). Several ARGs, that were most predominant in the duck feces samples, were also the most predominant in the shrimp gut samples from the duck–shrimp integrated farm. Redundancy analysis indicated that the abundances and distribution of ARGs formed three clusters: duck feces, water samples, and sediment and shrimp gut samples. The dominant genera in duck feces known as human pathogenic bacteria were potential hosts of ARGs, and were also dominant in the shrimp gut samples in the duck–shrimp integrated farm. Additionally, the abundances of dominant genera in the shrimp gut samples of the duck–shrimp integrated farm were 1.74–35.07-fold higher than those in the shrimp monoculture farm (p < 0.01). The duck–shrimp integrated farm had 3.36-fold and 4.94-fold higher abundances of ARGs and mobile genetic elements in the shrimp gut samples than those from the shrimp monoculture farm, respectively (p < 0.05). The results indicate that duck feces may be a crucial source of diverse and abundant ARGs spreading to reared shrimps in duck–shrimp integrated farms, posing a severe risk to public health.

https://www.sciencedirect.com/science/article/pii/S0147651322006418