A rapid ELISA method for detecting specific antibody level against nodavirus in the serum of the sea bass, Dicentrarchus labrax (L.): application to the screening of spawners in a sea bass hatchery.

摘要

The sera of 110 adult sea bass (78 females and 32 males) maintained in captivity in France were analysed for nodavirus antibodies using an indirect ELISA. 12 (16%) females were classified as positive and 44 (56%) as negative; 22 (28%) with low but detectable antibody levels were not classified. The percentage of seropositive males (3%) was significantly lower than the percentage of seropositive females. Repeated serological examination of 18 females (spawners) revealed no changes over 5 months. Immunization of female sea bass with heat-killed nodavirus induced antibody titres, as reflected by corresponding changes in ELISA optical density readings. The antibody levels increased 4 weeks after immunization and were still detectable 41 weeks after immunization. It is suggested that ELISA screening of spawners could be used to help prevent the vertical transmission of nodavirus in sea bass hatcheries.