Trichinella britovi recombinant proteins produced in Pichia pastoris expression system for specific IgG antibody detection in the sera of mice and pigs infected with Trichinella spp.

Trichinellosis, a disease caused by infection with Trichinella spp, poses an economic problem in the animal sector and a recurrent health problem for humans. Discovering the new diagnostic tests may be achieved by identification and production of species- and stage-specific recombinant proteins of Trichinella genus which are recognized by the host antibodies after infection. In this study the T. britovi proteins identified earlier in excretory-secretory (ES) products: CTRL, ES21 and HSP20, were cloned and produced using a eukaryotic Pichia pastoris system. Their immunodiagnostic properties were verified by measuring the abundance of specific IgG antibodies in sera from mice and pigs experimentally infected with T. britovi or T. spiralis. The rTbCTRL and the rTbES21 proteins were more effectively produced and stable than rTbHSP20. The most sensitive protein for serodiagnostic purposes occurred to be CTRL; anti-rTbCTRL IgG level increased at 41 days post infection (dpi) in pigs infected with T. britovi and 45 dpi for those infected with T. spiralis. The rTbES21 protein was the most specific for the T. britovi species, as no antibody titers were observed in pigs infected with T. spiralis. Following the multiple-antigen strategy, the combination of rTbCTRL + rTbES21 was applied in ELISA, but no significant difference in IgG level was detected in the tested conditions.