MONOCLONAL-ANTIBODIES AGAINST PROTEIN ANTIGENS OF SALMONELLAE CAUSINGPARATYPHOID FEVER AND THEIR DIAGNOSTIC APPLICATION

Hybrid clones producing monoclonal antibodies (MAbs) specific for Salm onella paratyphi A (72 clones), S. paratyphi B (9 clones) and S. parat yphi C (8 clones) were produced by using the affinity purified Salmone lla protein (Bp) as immunogens, MAbs to S. paratyphi A and S. paratyph i B reacted specifically with the 52 kDa homologous flagellin protein components while those to S. paratyphi C reacted with a 61 kDa flagell in protein component, The MAbs against S, paratyphi A and S. paratyphi B were used to establish a double antibody sandwich ELISA for detecti on of the 52 kDa flagellin antigens in serum samples from patients wit h acute paratyphoid A and paratyphoid B fever, With this assay system, 6.25 ng per mi of flagellin antigens of S. paratyphi A and S. paratyp hi B could be detected. However, the assay system could not detect the flagellin antigens in patients' sera, The presence of IgM antibodies to the 52 kDa antigens of S. paratyphi A and S. paratyphi B in the acu te sera from paratyphoid A or paratyphoid B patients suggested that th e 52 kDa protein components of both salmonellae are good immunogens fo r human and might be used as antigens for early diagnosis of paratypho id A and paratyphoid B fever.