Living in close proximity to the sediment of coastal areas, bivalves may be exposed to veterinary antibiotic residuals and microplastics (MPs) simultaneously. However, the immunotoxic impacts of veterinary antibiotics remain unknown in bivalves, let alone their interactions with MPs. Therefore, the immune responses of two representative veterinary antibiotics, oxytetracycline and florfenicol, was investigated in a bivalve species, the blood clam (Tegillarca granosa). The effects of the copresence of MPs on the immune responses triggered by these antibiotics were also analyzed. Results showed that exposure to antibiotics investigated led to significant alteration in hematic parameters and reduction in lectin content in serum. In addition to inducing ROS production, aggravating lipid peroxidation and DNA damage, and suppressing the hemocyte viability, antibiotic treatments also downregulated the expression of immune- and detoxification-related genes but upregulated apoptosis-related Caspase-3. Furthermore, the toxic impacts of antibiotics were found to be significantly increased by the copresence of MPs.

双壳类动物生活在沿海地区的沉积物附近，可能同时暴露于兽用抗生素残留物和微塑料（MPs）。但是，在双壳类动物中，兽用抗生素的免疫毒性影响仍然未知，更不用说它们与MP的相互作用了。因此，在双壳类动物血蛤（Tegillarca granosa）中研究了两种代表性的兽用抗生素土霉素和氟苯尼考的免疫反应。）。还分析了MP共存对这些抗生素引发的免疫反应的影响。结果表明，所研究的抗生素暴露导致血液参数的显着改变和血清中凝集素含量的降低。除了诱导ROS产生，加剧脂质过氧化和DNA损伤，抑制血细胞活力外，抗生素治疗还下调了免疫和解毒相关基因的表达，但上调了细胞凋亡相关的Caspase-3。此外，发现MP的共存会大大增加抗生素的毒性影响。