摘要

利用抗生素耐药基因（ARGs）作为海岸带环境中废水污染的新指标的报道还不多见。本研究探讨了受人类活动（包括污水密集排放）影响的近岸海域ARGs的分布和来源，表明ARGs可以作为近岸海域污水污染的重要指标。对10种ARG亚型包括编码磺胺类（sul1和sul2）、四环素类（tetB、tetG和tetX）、喹诺酮类（qnrA、qnrB和qnrS）和大环内酯类（ermF和ermT）进行了高频率检测。泗石里湾不同功能区ARGs绝对丰度在100-108拷贝/mL范围内变化较大。受污水处理厂（WWTPs）和污水污染的河流区ARGs总丰度较高，最高分别可达到6.1×106拷贝/mL和6.2×107拷贝/mL。TN、亚硝酸盐和硅酸盐与所有目标ARGs的丰度呈极显著正相关（p<0.01），铵和总有机碳与目标ARGs呈显著正相关。在受污水污染源（河流和污水处理厂）影响的区域，共鉴定出402对细菌与ARGs之间呈强相关和显著相关，而在其他样本中仅鉴定出232对相关。结果表明，在受污水污染的沿海水域中存在潜在的多重耐药细菌的出现和流行。研究结果表明，近岸海域ARGs的发生和分布主要受污水排放的影响。由于废水排放对近岸海域的ARGs污染具有重要影响，因此ARGs可以作为评价废水排放对近岸海域水质影响的新指标。

Rare information on using antibiotic resistance genes (ARGs) as new indicators for the wastewater contamination in coastal environment is available. This study investigated the distribution and sources of ARGs in a coastal bay influenced by anthropogenic activities including intensive wastewater discharge, which demonstrated that ARGs could be essential indicators for the wastewater contamination in coastal waters. Ten ARG subtypes encoding resistance to sulfonamides (sul1 and sul2), tetracyclines (tetB, tetG and tetX), quinolones (qnrA, qnrB and qnrS) and macrolides (ermF and ermT) were detected with high frequencies. The absolute abundances of ARGs in different functional zones of Sishili Bay differed greatly in the range of 10⁰–10⁸ copies/mL. The total abundances of ARGs in the zones influenced by wastewater treatment plants (WWTPs) and sewage polluted rivers were relatively higher with the maximum up to 6.1 × 10⁶ copies/mL and 6.2 × 10⁷ copies/mL, respectively. The TN, nitrite, and silicate had extremely significantly positive correlations (p < 0.01) with the abundances of all target ARGs, as well as ammonium and TOC had significantly positive correlations with the target ARGs. A total of 402 pairs of strong and significant correlations between bacteria and ARGs were identified in samples from the zones influenced by wastewater pollution sources (rivers and WWTPs), while only 232 pairs of correlations were identified in other samples. It indicated the occurrence and prevalence of potential multi-antibiotic resistant bacteria in coastal waters contaminated by wastewater. These findings revealed that the occurrence and distribution of ARGs in the coastal bay were mainly influenced by the wastewater discharge. ARGs might serve as new indicators for the influence of wastewater discharge on coastal water qualities, since the wastewater discharge has critical influences on ARGs pollution in coastal waters.

https://www.sciencedirect.com/science/article/abs/pii/S1470160X20302363