Effect of lipopolysaccharides from Vibrio alginolyticus on the Mx gene expression and virus recovery from gilthead sea bream (Sparus aurata L.) experimentally infected with Nodavirus

Infections with nodavirus affect a wild and farmed fish species throughout the world, mostly from the marine environment. The aim of this work was to determine the immune status of gilthead sea bream that comes as a result of a Nodavirus infection, induced by activation of the interferon response pathway by lipopolysaccharides from Vibrio alginolyticus and the expression of interferoninduced Mx protein in liver samples. The enhancement of Mx protein gene expression was detected in liver samples of experimentally nodavirus infected fish and, furthermore, the immunostimulant LPS of V. alginolyticus decreased almost three times the virus titration with respect to no-immunized or infected with nodavirus group of fish.

► Gilthead sea bream may be susceptible only to certain betanodavirus genotypes.
► Gilthead sea bream can be a transmitter of the Nodavirus disease to the sea bass or other susceptible species.
► The immunostimulant LPS of Vibrio alginolyticus has the ability to decreased the virus titration of Nodavirus.
► Nodavirus strongly induces Mx gene expression.