Trichinella spiralis: affinity purified antigen based diagnosis and immunoprophylaxis.

The current research introduces a trial to develop vaccine candidate against trichenosis. A method of affinity chromatography was adopted to purify a Trichinella spiralis larval extract. The isolated fraction resolved into six bands of 148 KDa, 133 KDa, 118.5 KDa, 101 KDa 98.5 KDa and 79.5 KDa as observed by SDS-PAGE. The diagnostic value of this fraction was checked against antibodies regularly collected from rats experimentally infected with trichinosis compared with that of crude larval extract by ELISA. The crude extract detected the antibodies as early as one week post infection and the maximum level was recorded four weeks post infection. The advantage of the isolated fraction over the crude extract in trichinosis diagnosis was clearly observed at high serum dilution reached to 1:4000. The protective value of the isolated fraction was also investigated. Rats immunized subcutaneously with affinity purified larval extract with Freund's adjuvant showed reduction in worm burden reached to 82%. IgG antibody response in immunized rats was higher than that of control infected animals as measured by ELISA. This response might be partially responsible for the observed protection.