Effect of Artemisia sieberi Besser extract on the humoral immunity of Oncorhynchus mykiss exposed to Streptococcus iniaie

Bacterial infections are one of the most important threats in the aquaculture. One of the most prevalent infectious diseases in rainbow troutfarms in recent years is Streptococcus in many countries. In recent years, the aromatic plants and their extracts have attracted a lot of attention. This study aimed to evaluate the effect of bacterial infection caused by strain of Streptococcus iniaie on the immune system of fish and the use of the extract of Artemisia sieberi to reduce the devastative effect of this bacterial infection on the immune system of Oncorhynchus mykiss. Reducing levels of the plasma peroxidase, IgM, total complement, lysozyme in fish exposed to bacteria showed the toxic effects of this bacteria on the immune system of fish. However, there was no significant change in the fish fed the extract of Artemisia sieberi and exposed to bacterial infection (P<0.05) compared to control group. This suggests the reinforcement and protective effect of the extract of Artemisia sieberi on the immune system of O. mykiss.