Lectins are hemagglutinating glycoproteins which act as pathogen recognition receptors that can bind to the pathogen-associated molecular patterns. Shrimp lectin (Md-Lec) is a lectin that is reported to have antimicrobial property. In this study, the CuS nanoparticles (CuS NPs) which were previously reported to have wide range of antimicrobial activity were conjugated with Md-Lec. Thus, their minimum inhibitory concentration (MIC) against aquatic pathogens was reduced four times than that of their individual activity. Moreover, antibacterial and antibiofilm assay was performed with Md-Lec, pCuS NPs, and Md-Lec conjugated with pCuS NPs (Md-Lec-pCuS NPs) against Aeromonas hydrophila at 25, 50, and 100 μg/mL. The hydrophobicity index and EPS (extracellular polysaccharide) production of A. hydrophila were decreased after treating with Md-Lec-pCuS NPs. The non-specific immune parameters—lysozyme assay, peroxidase assay, and respiratory burst activity—were elevated considerably in the infected fishes that are treated with Md-Lec-pCuS NPs at their MIC. Further, immune gene (COX2, MyD88, and LEC) expression analysis at different time intervals was also done in the infected Etroplus suratensis that are treated with Md-Lec-pCuS NPs at 3.13 μM concentration. The results reveal that the immune gene expression was upregulated at the 6th hour of infection in the infected fish that are treated with Md-Lec-pCuS NPs (3.13 μM) and thus it can be used as a therapeutic agent which can act as an immunostimulant for the production of disease-free fishes in aquaculture industry.

凝集素是血凝糖蛋白，其可以与病原体相关的分子模式结合，充当病原体识别受体。虾凝集素（Md- Lec）是一种据报道具有抗微生物特性的凝集素。在这项研究中，先前报道具有广泛抗菌活性的CuS纳米颗粒（CuS NPs）与Md- Lec结合。因此，它们对水生病原体的最小抑菌浓度（MIC）比其单独活性降低了四倍。而且，抗菌剂和抗生物膜测定用MD-进行LEC，个PCU的NP和MD- LEC用的PCU的NP（MD-缀合LEC -pCuS NPS）对嗜水气单浓度分别为25、50和100μg/ mL。疏水性指数和EPS（胞外多糖）生产嗜水与MD-治疗后降低LEC -pCuS的NP。非特异性免疫参数-溶菌酶测定法，过氧化物酶测定法和呼吸爆发活性-在受MIC感染Md- Lec- pCuS NPs处理的受感染鱼中显着提高。此外，还对用Md- Lec处理的被感染的Etroplus suratensis进行了不同时间间隔的免疫基因（COX2，MyD88和LEC）表达分析。-pCuS NPs浓度为3.13μM。结果表明，在用Md- Lec- pCuS NPs（3.13μM）处理的被感染鱼中，感染后第6小时免疫基因表达被上调，因此可以用作可作为免疫刺激剂的治疗剂用于水产养殖业生产无病鱼。