Development of an indirect-ELISA for detecting specific antibody to F41 pilus protein of enterotoxigenic Escherichia coli

An indirect enzyme-linked immunosorbent assay(ELISA) was developed based on a purified recombinant F41 pili protein of enterotoxigenic Escherichia coli(ETEC).The optimum test conditions were as follows:the concentration of coating antigen was 0.26 μg per well,the dilution of serum and HRP-labeled mice anti-bovine IgG were 1∶800 and 1∶6 000,respectively,30 g/L gelatin blocked for 1 h,and the reaction time of coloration was 10 min.The specificity,sensitivity,reproducibility and stability were evaluated.Compared with antigen from PCR,97.4% agreement for positive and negative samples were obtained.The results indicated that the indirect ELISA could be used for detecting anti-F41 pili antibodies of ETEC.