Comparison of Different Antigens for Caev Diagnosis by Elisa

Veterinarni Medicina 38, 1993, 237-244

The most adequate means of diagnosing infections with caprine arthritis encephalitis (CAE) and Maedi-Visna (MV) viruses is the demonstration of antibodies to these viruses in milk or in blood serum. Various techniques and a range of different antigen preparations can been used for this purpose. We have evaluated two different whole virus antigen preparations derived from lamb synovial cells infected with CAE and MV viruses and recombinant antigen containing the capsid protein expressed in E coli in ELISA test. The suitability of different detergents for solubilization of whole virus particles is shown in Tab. I. The detergents used were ether (50 %, 10 min, 37-degrees-C), octyl-beta-D glucopyranoside - OGP (2 %, 2 h, 37-degrees-C), and sodium dodecylsulphate SDS (0.125 %, 10 min, 37-degrees-C). Antigens prepared with SDS gave the best results and were then used in the following antigen comparative study. All antigens (whole virus and recombinant core protein) were used for the coating of ELISA plates and were evaluated on a panel of 130 sera. In general, whole virus antigens prepared from CAE- and MV-viruses gave identical results. The specificity achieved with recombinant antigen was superior but the sensitivity was lower compared with whole virus antigen. Immunoblotting served as the gold standard for discordant results. The other aim of our study was to compare antibody detection in blood serum and milk. Using whole virus antigen, antibodies could be detected with higher specificity and sensitivity in milk than in blood serum (Tab. II.). Titration of blood serum and milk samples of four animals revealed the higher antibody titre in blood serum than in milk (Tab. III)

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