DEVELOPMENT OF AN ANTIBODY FILTRATION-ASSISTED SINGLE-DILUTION CHEMILUMINOMETRIC IMMUNOASSAY FOR POTENCY TESTING OF PISCIRICKETTSIA SALMONIS VACCINES

LAVORIA, MARÍA DE LOS ÁNGELES; WILDA, MAXIMILIANO; ERGUIS, MATÍAS; FRANCO MAHECHA, OLGA; GRIGERA, PABLO; IGLESIAS, MARCELA; CAPOZZO, A.V.

Lima

Congreso; InmunoPerú 2012; 2012

Asociación Latinoamericana de Inmunología

Refinement of techniques has been applied for many veterinary diseases for which challenge with live pathogens could be substituted by serology. However, little progress has been made in the development of alternative batch potency tests for fish. This study reports the development of a Single-dilution Filtration-Assisted Chemiluminometric Immunoassay (Sd-FAL-ELISA), an easy to standardize and reliable method applied to the measurement of anti Piscirickettsia salmonis IgM in individual or pooled, serum and epithelial mucus samples. Relative-light units values (RLU) obtained by Sd-FAL-ELISA were proportional to antibody levels in serum. The assay was set up to test a single 1:200 dilution of sera or a 1:50 dilution of mucus. Sd-FAL-ELISA discriminated positive and negative samples. Serum Sd-FAL-ELISA yielded a sensitivity of 90% and a specificity of 96%. Sd-FAL-ELISA was applied to evaluate the effectiveness of two experimental vaccines together with an inactivated commercial vaccine. RPS values were of 54.5% and 40.9% for the experimental vaccines, while the commercial vaccine was fully protective (RPS=86.4%). Individual and pooled serum and mucus samples were evaluated in a FAL-ELISA, five days before challenge. Sd-FAL-ELISA from pooled and individual serum samples gave cRLU values that increased with observed RPS values, indicating a correlation between protection and specific IgM levels. Evaluation from mucus samples discriminated the protective vaccine from the others. This is the first report on an indirect assessment to in vivo challenge for fish vaccines. Further studies are needed to validate the application of this assay. enviar mensaje