Microplastics and antibiotics widely coexist in the aquatic environment, especially in mariculture regions. However, antibiotics adsorbed on microplastics and their role in the colonization of microorganisms on microplastics are poorly understood. Therefore, in-situ aging experiments were conducted to investigate the impact of antibiotics and microplastics co-occurrence on microorganisms and assess their potential risks to human health. Results showed that antibiotics were adsorbed selectively on microplastics, with 29 investigated antibiotics (n = 40) detected in surrounding water but only 6 investigated antibiotics were adsorbed on microplastics. The concentration of antibiotics accumulated on microplastics was controlled by microplastic types and environmental conditions. For example, aged polypropylene (PP) had more developed pore structures resulting in higher adsorption of antibiotics than other microplastic types. High-throughput sequencing showed higher diversity and distinct composition of microorganisms attached to the microplastics than the surrounding water. Opportunistic pathogenic bacteria such as Mycobacterium possessed positive relationships with tetracycline and doxycycline on aged microplastics, which showed adsorbed antibiotics on aged microplastics could benefit pathogens colonized on the microplastics and spread into unaffected ecosystems, marine organisms even humans. The health risk quotient (HQ) implied the potential human health risk of consuming commercial seafood polluted by antibiotics and microplastic loaded with antibiotics. This study revealed the interaction of antibiotics and microorganisms with aged microplastics in aquaculture systems, providing a novel insight into their synergistic effects on ecological and human health.

微塑料和抗生素在水生环境中广泛共存，特别是在海水养殖区。然而，人们对吸附在微塑料上的抗生素及其在微塑料上微生物定植中的作用知之甚少。因此，进行了原位老化实验，以研究抗生素和微塑料共存对微生物的影响，并评估它们对人类健康的潜在风险。结果表明，抗生素被选择性吸附在微塑料上，在周围水中检测到 29 种被调查的抗生素（n = 40），但只有 6 种被调查的抗生素被吸附在微塑料上。累积在微塑料上的抗生素浓度受微塑料类型和环境条件控制。例如，老化聚丙烯 (PP) 具有更发达的孔结构，导致抗生素的吸附性高于其他微塑料类型。高通量测序显示，与周围水相比，附着在微塑料上的微生物具有更高的多样性和独特的组成。机会致病菌如分枝杆菌与老化微塑料上的四环素和强力霉素具有正相关关系，这表明老化微塑料上吸附的抗生素可以使定植在微塑料上的病原体受益，并传播到未受影响的生态系统、海洋生物甚至人类中。健康风险商 (HQ) 暗示食用被抗生素和含有抗生素的微塑料污染的商业海鲜可能对人类健康构成风险。这项研究揭示了水产养殖系统中抗生素和微生物与老化微塑料的相互作用，为它们对生态和人类健康的协同作用提供了新的见解。