Praparationand Identification Of Monoclonal Antibodies Against The Subunit FedE Of F18 Fimbriae Of Escherichia Coli

Edema disease and diarrhea of weaned piglets that have important impact on stock raising,which are caused by Escherichia coli F18.The F18 fimbriae have two serotypes F18ab and F18ac,which help Enterotoxigenic Escherichia coli(ETEC) and Verotoxigenic Escherichia coli(VTEC) settle in the intestines.The F18 fimbriae have five subunits.The major structure of fimbriae is made up of polymerid of the subunit A.The subunit B and Care the chaperone or usher protein in the course of maturing ,assembling and synthesization of fimbriae. The subunit F is the adhesin of the fimbriae.But it's unknown for us the relation bewteen the subunit E and the adherence of bacteriae.To study the function of subunit E ,BABL/c mice were immunized by the fusion protein(GST-FedE).SP2/O myeloma cells and spleen cells of the immunized mouse were fused by PEG-1450.The hybridoma culture supernatants were screened for anti-FedE specific antibody by indirect-ELISA .The two cell lines named FedE-D5 and FedE-E2 can produce monoclonal antibodies steadily.The ELISA titres of mouse ascites were 212 and 214 respectively.The results of indirect immunofluorenscene test and the adherence test showed that monoclonal antibody secreted by cell lines D5 and E2 can identify the natural F18 fimbriae,and they can be used for detection.But they can not prevent the Escherichia coli F18 from adhering the small intestine epithelial cells.We think the subunit E has nothing with the adherence of bacteria.