Detection of Humoral Response to Streptococcus iniae Infection of Nile Tilapia, Oreochromis niloticus, by a Monoclonal Antibody-Based ELISA

摘要

A monoclonal antibody (Mab) was developed that was specific for Nile tilapia, Oreochromis niloticus, immunoglobulin (Ig). This Mab was identified as isotype IgGl and showed no cross-reactivity with other fish species tested by indirect ELISA. Furthertesting by Western blotting indicated the Mab to be specific for the heavy chain of Nile tilapia Ig. A specific immunoassay was developed to measure immune response to Streptococcus iniae in Nile tilapia utilizing this Mab. There was a high degree of correlation with this assay compared to agglutination assay and ELISA based on polyclonal antibodies developed in goat. The Mab offers the potential for increased accuracy in the detection of vaccine and disease response to S. iniae in this commercially important fish species.