Inhibitory effect of nano selenium on the recurrence of aeromonas hydrophila bacteria in cyprinus carpio

Abstract

The recurrence of bacterial infection in fish is related to several factors, including the immune status and oxidative state. A total number of 240 Cyprinus carpio was divided into four treatments; control (T1) fed on free diet and three treatments (T2-4) fed on supplemented diet with nanoparticles of selenium Se NPs (1 mg/kg fish feed) for 10, 20, and 30 days, respectively. Supplemented fish with Se NPs for 30 days (T4) had significantly higher total protein and globulin content (5.83 and 3.1 g/dl, respectively) compared to the control indicating an enhanced immune status. Fish fed on Se NPs supplementation for 30 days (T4) recorded significantly higher anti-inflammatory cytokine “interleukin (IL)-10", while the pro-inflammatory cytokines “tumour necrosis factor (TNF)-α, IL-1β, and IL-8" reduced significantly compared to the control. Antioxidant enzymes (glutathione peroxidase GPx, catalase CAT, and superoxide dismutase SOD) were gradually and significantly enhanced in time-dependent manner. Genotoxicity (DNA damages, DNA fragmentation, and presence of micronuclei) was low in supplemented fish while challenged fish performed in an opposite manner. However, Se NPs supplementation had overcome those withdraws causing a decrease in the signs of genotoxicity. Se NPs improved the immunity, antioxidant, and histopathological status of C. carpio showing enhancements in disease resistance, as reducing the chance of recurrence of Aeromonas hydrophila infection and genotoxicity.