摘要

对水生环境中抗生素抗性基因（ARG）的发生和丰度给予了相当大的关注。然而，ARG在水产养殖环境和饲养生物中的时间变化和传播需要进一步研究。本研究调查了中国南方珠江三角洲地区饲养期水源，虾塘水，沉积物和虾的ARGs和细菌群落的丰度和多样性。结果显示sul1，qnrD，cmlA和floR是水产养殖样本中主要的ARG。在饲养期间观察到池塘水样品中ARGs丰度下降的趋势，而在沉积物和虾样品中观察到增加的趋势。 ARGs在水源中的总浓度显着高于虾池水中的浓度（p <0.05）。池塘水体和沉积物中ARG总浓度存在显着负相关（p <0.01）。成年虾肠道中ARGs总含量比幼虾高4.48-19.0倍。类似于水源和池塘水，cmlA和sul1是虾肠道中主要的ARGs。虾肠道中的细菌群落从幼年变为成年。本研究结果表明，饲养期间ARGs的丰度在时间上各不相同。水源是向水产养殖环境和饲养生物传播ARGs的重要媒介。 Sul1可作为中国南方珠江三角洲河口水产养殖中ARGs潜在指标。这项研究代表了水产养殖中ARGs丰度和传播时间变化的案例研究，并且是对食品安全和人类健康潜在风险的参考。

Considerable attention has been paid to the occurrence and abundance of antibioticresistance genes (ARGs) in aquatic environments. However, the temporal variation and dissemination of ARGs in aquaculture environments and reared organisms need further study. This study investigated the abundance and diversity of ARGs and bacterial community in water source, shrimp pond water, sediment, and shrimps during the rearing period in Pearl River Delta region, South China. The results showed that sul1, qnrD,cmlA, and floR were the predominant ARGs in the aquaculture samples. A trend of decreasing abundance of ARGs was observed for pond water samples during the rearing period, whereas an increasing trend was observed in the sediment and shrimp samples. The total concentration of ARGs in water source was significantly higher than that in shrimp pond water (p < 0.05). A significant negative correlation was found between the total concentrations of ARGs in pond waters and sediments (p < 0.01). The total abundances of ARGs in intestinal tract of adult shrimps were 4.48–19.0 times higher than those in juvenile shrimps. Similar to water source and pond water, cmlA and sul1 were the predominant ARGs in shrimp intestinal tract. The bacterial community in the shrimp intestinal tract changed greatly from juvenile to adult. The results of the present study indicated that the abundances of ARGs in aquaculture varied temporally during the rearing period. Water source was an important medium disseminating ARGs to the aquaculture environments and reared organisms. Sul1 could be used as a potential indicator for ARGs in both water and sediment in aquaculture in the estuary of the Pearl River Delta, South China. This study represents a case study for the temporal variation of abundance and dissemination of ARGs in aquaculture and is a reference for potential risks to food safety and human health.

https://www.sciencedirect.com/science/article/pii/S0048969717317448