Evaluation of Dot Immunogold Filtration Assay (DIGFA) By Recombinant Protein EPC1 for Anti- Echinococcus granulosus IgG Antibody

Abstract

Background: Cystic echinococcosis is an important zoonosis caused by the Echinococcus granulosus with a substantial impact in human and animal health in en-demic areas. The purpose of the present study was serodiagnosis optimizing of dog echinococcosis in order to achieve a rapid diagnostic method. Methods:Eight dogs were challenged with protoscoleces in order to have posi-tive echinococcosis serum and 2 two-month old puppies were used as uninfected controls. Colloidal gold was prepared by controlled reduction of a boiling solu-tion of chloroauric acid (H [AuCl4]) with sodium citrate and labeled with recom-binant EPC1. Dot immunogold filtration assay (DIGFA) was developed by coat-ing rEPC1 labeled colloidal gold on nitrocellulose membrane. The canine sera, taken three times including, 15, 28 and 35 days post infection were tested. A total of 30 serum samples including 24 sera from 8 infected dogs and 6 sera from 2 puppies were comparatively detected with both DIGFA and ELISA. Results:Gold labeled antigen, showed a dark purple dot with agglutination parti-cles in positive sera and light purple dot without agglutination in negative sera. Among 30 serum samples, 23 were positive and 7 were negative with DIGFA and 24 were positive, 6 were negative with ELISA. Conclusion:DIGFA as a rapid and simple procedure could be utilized in quickly diagnosis of echinococcosis.

Keywords

• Dot immunogold filtration assay
• Echinococcus granulosus
• Recombinant EPC1
• Serodiagnosis