Background: Echinococcus granulosus protoscolex antigen (PSAg) is a protein with significant immunological properties having higher sensitivity and specificity in ELISA. It lowers cross-reaction with antibodies of other parasites and thus its application is recommended in serological diagnosis. Labelling of ELISA with nano-gold particles improved the diagnostic abilities of the laboratory technique in hydatidosis detection.
Objective: To evaluate the use of nano-gold dot-ELISA for isolation of E. granulosus PSAg and its application in serodiagnosis of hydatidosis in humans and animals in comparison with dot-ELISA.
Material and Methods: Hydatid cyst PSAg was isolated and used for immunization of rabbits to raise IgG polyclonal antibodies (pAb) in antisera. These sera were labeled with horseradish peroxidase (HRP) and used for detection of circulating PSAg in sera of human cases and camels and sheep by dot-ELISA and nano-gold dot-ELISA.
Results: Conjugation of the anti-protoscolex pAb with gold nano-particles increased the sensitivity of antigen detection by nano-gold dot-ELISA to 94.4% and specificity to 90%, with positive and negative predictive values of 94.4% and 90%, and an accuracy of detection of 92.9%in both human and animal sera.
Conclusion: Nano-gold dot-ELISA technique is more sensitive than dot-ELISA for detection of hydatidosis antigen both in human and Background
Use of nanotechnology in clinical diagnosis meets the demands for increased
sensitivity and early detection in less time.
Purpose
The aim of this study was to evaluate the nanogold particles-based dot-enzymelinked
immunosorbent assay (ELISA) as a test for detection of protoscolices antigen
in serum samples of infected animals in comparison with traditional dot-ELISA.
Methods
A total of 76 blood samples were collected and included in the study: 36 sample of
hydatidosis confirmed cases, 20 samples infected with other parasitic infection
except hydatidosis as positive controls, and 20 samples as negative controls. Dot-
ELISA was applied using two polyclonal antibodies against protoscolices antigen,
the purified immunoglobulin G (IgG) polyclonal antibodies, and peroxidaseconjugated
IgG, whereas in the nanogold dot-ELISA, the purified IgG polyclonal
antibodies were conjugated with nanogold particles.
Results
On detection of protoscolices antigen by dot-ELISA, 31 (86.1%) of 36 serum
samples were found to be positive, whereas nanogold dot-ELISA gave 34
(94.4%) positive serum samples. Dot-ELISA with nanogold particles had higher
values than dot-ELISA regarding sensitivity (94.4 vs. 86.1%), positive predictive
value (94.4 vs. 93.9%), negative predictive value (78.3 vs. 90%), and accuracy
(92.9 vs. 87.5%), but specificity (90%) was the same for both tests.
Conclusion
Nanoparticles-based dot-ELISA is superior over traditional dot-ELISA for the
detection of protoscolices antigen in hydatidosis. Dot-ELISA is rapid and easy to
perform and the results can be read with the naked eye, so it does not require
expensive equipment.animal samples.