Document Type

Thesis - University Access Only

Award Date

1995

Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Michael B. Hildreth

Abstract

In an attempt to develop a fecal ELISA diagnostic test for detecting dog Echinococcus multilocular infections, proteins from four different E. multilocularis sources were collected: 1 & 2) protoscolex and adult excretory/secretory (E/S) antigens, 3 & 4) protoscolex and adult tegumental proteins. Taenia E/S and tegument proteins were also collected to identify any antigenic cross-reactivity between the two cestodes in the diagnostic test. SDS-PAGE analysis of the proteins from each source suggested that they may share components with each other at one or more molecular weight ranges. Polyclonal antibodies (Ab) were raised against protoscolex E/S antigen; the specificity of the immune serum against its own antigens was determined in Ouchterlony double diffusion assays and in immunocytochemistry. Specificity of IgG purified from the immune serum was determined in an antibody sandwich ELISA. Comparisons of the protoscolex E/S antigen with proteins from the other three E. multilocularis sources indicated that: 1) double diffusion assays revealed a line of partial identity indicating partial antigenic similarity between the protoscolex E/S antigens and the adult E/S antigen; 2) immunocytochemical analysis revealed binding of antibodies to the teguments of whole and sections of protoscoleces and to whole adults, indicating their antigenic relationship; 3) antibody sandwich ELISA using the protoscolex IgG against protoscolex, adult E/S and tegumental proteins all showed positive results indicating their shared antigenicity. Cross-reactivity of E. multilocularis anti-protoscolex antibodies with Taenia proteins demonstrated that: 1) Ouchterlony double diffusion assays did not reveal any cross-reactivity suggesting their antigenic differences; 2) immunocytochemistry involving Taenia proglottids did not reveal any binding of the antibodies to the proglottids clearly suggesting the antigenic differences between the two cestodes; 3) However, antibody sandwich ELISA using the E/S and tegument proteins as antigens showed positive results indicating the cross-reactivity and antigenic relation between the two cestodes. We conclude, that since protoscolex and adult E/S proteins of E. multilocularis are antigenically related, it may be possible to replace adult E/S antigens with protoscolex E/S antigens in developing a fecal ELISA. However, the cross-reactivity of the E. multilocularis protoscolex-antibody with both Taenia proteins in the antibody sandwich ELISA, but not in the double diffusion assays or in the immunocytochemical analysis of indicated that further studies are needed to define the true specificity of these antibodies. It may be necessary to improve their specificity before they can be implemented into fecal ELISA.

Library of Congress Subject Headings

Dogs -- Parasites
Echinococcosis -- Diagnosis
Echinococcus
Parasite antigens

Format

application/pdf

Publisher

South Dakota State University

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Rights Statement

In Copyright