This study aims to screen the diagnostic biomarkers for fecal antigen of Echinococcus granulosus(E.granulosus)in dogs with high specificity and sensitivity.The sheep-derived EgPSC artificially infected dogs were collected,and the negative and positive fecal samples of dogs with E.granulosus were prepared by arecoline hydrobromide leakage method.Polyclonal antibody,negative fecal antigen-polyclonal antibody conjugates and positive fecal antigen-polyclonal antibody conju-gates were purified by ammonium sulfate precipitation and affinity chromatography,three groups of samples were detected by ELISA and Western blot,LC-MS/MS and bioinformatics analysis were performed on the three groups of samples.The positive fecal antigen-polyclonal antibody con-jugate was used as the treatment group,the polyclonal antibody and the negative fecal antigen-polyclonal antibody conjugates were used as the control groups to screen the unique peptides of the treatment group.ELISA and Western blot showed that only the positive fecal antigen-polyclonal antibody conjugates were positive.According to LC-MS/MS and bioinformatics analysis,11 unique peptides were screened out only in the treatment group.Among them,3 proteins were related to E.granulosus,namely dysferlin,integrator complex 9 and diagnostic antigen gp50,which were mem-brane-associated proteins,INT complex components and diagnostic antigens.This study has pre-liminarily screened out three candidate canine E.granulosus fecal antigen diagnostic markers,pro-viding a reference for further exploration of diagnostic standards for E.granulosus,screening of echinococcosis target genes,and vaccine development.

This study aims to screen the diagnostic biomarkers for fecal antigen of Echinococcus granulosus(E.granulosus)in dogs with high specificity and sensitivity.The sheep-derived EgPSC artificially infected dogs were collected,and the negative and positive fecal samples of dogs with E.granulosus were prepared by arecoline hydrobromide leakage method.Polyclonal antibody,negative fecal antigen-polyclonal antibody conjugates and positive fecal antigen-polyclonal antibody conju-gates were purified by ammonium sulfate precipitation and affinity chromatography,three groups of samples were detected by ELISA and Western blot,LC-MS/MS and bioinformatics analysis were performed on the three groups of samples.The positive fecal antigen-polyclonal antibody con-jugate was used as the treatment group,the polyclonal antibody and the negative fecal antigen-polyclonal antibody conjugates were used as the control groups to screen the unique peptides of the treatment group.ELISA and Western blot showed that only the positive fecal antigen-polyclonal antibody conjugates were positive.According to LC-MS/MS and bioinformatics analysis,11 unique peptides were screened out only in the treatment group.Among them,3 proteins were related to E.granulosus,namely dysferlin,integrator complex 9 and diagnostic antigen gp50,which were mem-brane-associated proteins,INT complex components and diagnostic antigens.This study has pre-liminarily screened out three candidate canine E.granulosus fecal antigen diagnostic markers,pro-viding a reference for further exploration of diagnostic standards for E.granulosus,screening of echinococcosis target genes,and vaccine development.