Determination of Immunogenic Relevant Antigens in the Excretory-Secretory (ES) Products and the Lysates of Ascaridia galli Larvae

Abstract

Background: Ascaridia galli, the largest nematode of small intestine of birds, especially the native poultry, may give rise to serious illness, pathological defects and economical losses even in modern poultry production systems. Although various measures have been undertaken to vaccinate poultry against A.galli, no satisfactory results were obtained so far. However, there is no report on the efficacy of excretory-secretory (ES) proteins of A.galli larvae in immunization of poultry. Thus, the aim of the present research project was based on the use of the ES products of the larvae, in order to find the protective anti­gens.

Methods: Five hundred native poultry were autopsied and adult A.galli was removed form their intestines. The eggs were harvested form the uterus of female worms and cultured at 25 ˚C in water containing 0.1 N sulphuric acid for almost a fort­night. The larvae were then freed mechanically and kept in Earl^'s salt solution for a few days. The supernatant solution of alive larvae containing the ES products of the larvae, as well as the sonicated alive and dead larvae, was analyzed by SDS-PAGE.

Result: Many protein fractions of 15 kDa up to 200 kDa were demonstrated in lysate of these larvae. Using the serum of a hen, infected with a high numbers of A.galli, an immunogenic antigen was identified between 55 kDa to 72 kDa by Western blotting procedure.

Conclusion: Finding the protein band between 55 and 72 kDa can be promising for preparation of vaccine, though more investigations are needed to prove the protective ability of this antigen.