“Evaluation of Imoviral supplement effects on acute-phase response in Sparus aurata after Vibrio anguillarum infection (7215)”

Evaluation of Imoviral supplement effects on acute-phase response in Sparus aurata after Vibrio anguillarum infection

Introduction

Research on food additives to boost immune responses in marine organisms is crucial for aquaculture. This study evaluated the efficacy of Imoviral® complex in Sparus aurata, a dietary supplement with exclusively natural extracts such as uncaria (Uncaria tomentosa), shiitake (Lentinula edodes), beta-glucan and blackcurrant (Ribes nigrum), whose immunostimulant and analgesic properties have been demonstrated.

Methodology

An acute phase response (APR) was experimentally induced in Sparus aurata by intraperitoneal (IP) injection of Vibrio anguillarum. One hundred fish (12.96 ± 0.96g) obtained from a fish farm were randomly assigned to 5 experimental groups (in duplicate). After the feeding period, an experimental IP infection with V. anguillarum was performed and the APR was evaluated at different time points i.e., 1, 24, 72 and 168 hours post infection (hpi). The IP infection has been performed with a virulent suspension of V. anguillarum or PBS (control). RNA samples have been collected from spleen tissues at different time points. The immune response was analysed by examining the gene expression of pro-inflammatory cytokines (IL-1β, TNF-α) antimicrobial peptides (defensin, hepcidin), antioxidant enzymes (CAT, SOD, GST, Cu-Zn-SOD), anti-inflammatory cytokines TGF-β and Interleukin-10. Experimental procedures have been performed at Centre for Experimental Fish Pathology, University of Messina, accredited for use of aquatic organisms for experimental purposes (DM n.39/ March/2006).

Results

The results showed a significant increase in the expression of TNF-α, IL-1β and antimicrobial peptides in the early stages of infection in fish fed with Imoviral®, suggesting an enhanced immune response compared to control groups. Fish fed with Imoviral® showed higher gene expression of TNF-α and il-10 in the first 72 hpi. In contrast, in the control groups, the expression of these genes was less pronounced. Antimicrobial peptide gene expression analysis revealed a marked modulation of hepcidin and defensin, with significantly higher levels in fish fed commercial diets than those fed Imoviral®. Fish infected with V. anguillarum and fed commercial diets showed upregulated expression of antioxidant genes, which varied according to time and group. TgFb showed temporal variations within groups. The study found no significant differences in weight gain or growth rates between groups, indicating Imoviral® supplementation did not harm fish development.

Conclusion

In conclusion, Imoviral? showed to enhance the immune response of S. aurata to V. anguillarum infection, suggesting its potential to boost disease resistance in aquaculture without affecting growth performances. These findings warrant further research into the underlying immune mechanisms in marine species.

1. CAPPARUCCI, FABIANO, UNIVERSITY OF MESSINA, Presenter
2. Natale, Sabrina, UNIVERSITY OF MESSINA, Author
3. Savoca, Serena, UNIVERSITY OF MESSINA, Author
4. Bragason, Birkir Thor, Institute for Experimental Pathology, University of Iceland, Author
5. Giannetto, Alessia, UNIVERSITY OF MESSINA, Author
6. Marino, Fabio, UNIVERSITY OF MESSINA, Author
7. Iaria, Carmelo, UNIVERSITY OF MESSINA, Author