摘要

      抗生素的滥用导致了水产养殖系统中抗生素耐药基因（ARGs）的繁殖。尽管循环系统已被认为是防止抗生素和ARGs污染沿海水域的一种有前途的方法，但关于ARGs在循环海水养殖系统中的分布和扩散的信息却很少。本研究首次研究了ARGs在沿海循环海水养殖系统中的增殖。检测了10种ARGs亚型，包括tet（tetB，tetG，tetX）、sul（sul1，sul2）、qnr（qnrA，qnrB，qnrS）和erm（ermF，ermT）。海水养殖场检测到的ARGs绝对丰度大于1 × 104拷贝/mL，其中磺胺类耐药基因（sul1和sul2）最为丰富，丰度为3.5 ××107-6.5 ××1010拷贝/mL，抗生素与ARGs之间无明显相关性。部分细菌与两种或两种以上的ARG呈显著正相关，提示多药耐药的发生。循环系统污水处理的流化床生物滤池是ARGs的主要滋生地，而紫外线杀菌工艺可以降低ARGs。ARGs的最高通量（6.5 × 1021个拷贝/d）表明，在循环海水养殖系统中，排泄物和残留诱饵是ARGs进入环境的主要通道。

       The abuse of antibiotics has caused the propagation of antibiotic resistance genes (ARGs) in aquaculture systems. Although the recirculating systems have been considered as a promising approach for preventing the coastal water pollution of antibiotics and ARG, rare information is available on the distribution and proliferation of ARGs in the recirculating mariculture system. This study firstly investigated the proliferation of ARGs in coastal recirculating mariculture systems. Ten subtypes of ARGs including tet (tetB, tetG, tetX), sul (sul1, sul2), qnr (qnrA, qnrB, qnrS), and erm (ermF, ermT) were detected. The absolute abundances of the ARGs detected in the mariculture farm were more than 1 × 10⁴ copies/mL. The sulfonamide resistance genes (sul1 and sul2) were the most abundant ARGs with the abundance of 3.5 × 10⁷-6.5 × 10¹⁰ copies/mL. No obvious correlation existed between the antibiotics and ARGs. Some bacteria were positively correlated with two or more ARGs to indicate the occurrence of multidrug resistance. The fluidized-bed biofilter for wastewater treatment in the recirculating system was the main breeding ground for ARGs while the UV sterilization process could reduce the ARGs. The highest flux of ARGs (6.5 × 10²¹ copies/d) indicated that the discharge of feces and residual baits was the main gateway for ARGs in the recirculating mariculture system to enter the environments.

        https://www.sciencedirect.com/science/article/pii/S0269749118352758?via%3Dihub