Isolation and identification of excretory-secretory and somatic antigens from the Oestrus ovis larvae by SDS-PAGE and immunoblotting

Oestrus ovis is an economically important parasite of small ruminants and a zoonotic parasite with many reports of ophthalmomyiasis in human from Iran and other countries. The aim of the peresent study was the isolation and identification of excretory-secretory (ES) and somatic (S) antigens of O. ovis second and third stage larvae (L2, L3) collected from Arabi sheep breeds located in southwest of Iran. Positive sera were prepared by marking the sheep, taking blood sample and direct observation of the parasite in the head. Somatic antigens of the larvae (SL2, SL3) were prepared by sonication. Larval excretory-secretory antigens (ESL2, ESL3) were prepared by incubation the larvae in RPMI-1640 RPMI medium. Electrophoretic protein profiles of ESL2 two, ESL3 seven, SL2 eight, SL3 fifteen bands (from 79.0 to below 14.4 KDa) were shown. In immunoblotting with positive sera, four common bands in SL2 and SL3 at 58, 42.0, 29.0 and 28.0 kDa, one specific band in SL3 at 47.0 kDa and one band in ESL2, at 28.0 kDa, and three bands in ESL3 at 58.0, 42.0, 29.0 and 28.0 kDa were recognized. Among the profiles, the 28 kDa protein was the most common antigenic component. Nevertheless, the antigenic proteins 29, 58 kDa were a common protein in electrophoretic patterns of both S and ES proteins of L2 and L3 but, 42.0 kDa antigen the only one detected in immunoblot but not in S and ES protein profiles of the larvae. Therefore, the antigens 29.0, 42.0 and 58.0 kDa can be used for further studies of protective effects and serological diagnostic methods.