Sewage treatment plants (STPs) are considered as “hotspots” for the emergence and proliferation of antibiotic resistance. However, the impact of heavy metals contamination on dispersal of antibiotic resistance in STPs is poorly understood. This study simultaneously investigated the effect of removal of metal and antibiotic resistance as well as mobile elements at different treatment units of STPs in Delhi, India. Results showed that treatment technologies used in STPs were inefficient for the complete removal of metal and antibiotic resistance, posing an ecological risk of co-selection of antibiotic resistance. The strong correlations were observed between heavy metals, metal and antibiotic resistance, and integrons, implying that antibiotic resistance may be exacerbated in the presence of heavy metals via integrons, and that metal and antibiotic resistance share a common or closely associated mechanism. We quantified an MRG rcnA, conferring resistance to Co and Ni, and identified that it was more abundant than all MRGs, ARGs, integrons, and 16S rRNA, suggesting rcnA could be important in antibiotic resistance dissemination in the environment. The associations between heavy metals, metal and antibiotic resistance, and integrons highlight the need for additional research to better understand the mechanism of co-selection as well as to improve the removal efficacy of current treatment systems.

污水处理厂 (STP) 被认为是抗生素耐药性出现和扩散的“热点”。然而，人们对重金属污染对 STP 中抗生素耐药性传播的影响知之甚少。本研究同时调查了在印度德里的不同 STP 处理单元中去除金属和抗生素耐药性以及移动元素的效果。结果表明，在 STPs 中使用的处理技术对于完全去除金属和抗生素耐药性是无效的，存在共同选择抗生素耐药性的生态风险。在重金属、金属和抗生素耐药性以及整合子之间观察到强相关性，这意味着在重金属存在的情况下，整合子可能会加剧抗生素耐药性，并且金属和抗生素耐药性具有共同的或密切相关的机制。我们量化了一个 MRGrcnA，赋予对 Co 和 Ni 的抗性，并确定它比所有 MRG、ARG、整合子和 16S rRNA 更丰富，这表明rcnA在环境中抗生素耐药性传播中可能很重要。重金属、金属和抗生素耐药性以及整合子之间的关联凸显了需要进行额外研究以更好地了解共选择机制以及提高当前治疗系统的去除效果。