The first analysis of Trichinella spiralis and Trichinella britovi adult worm excretory-secretory proteins by two-dimensional electrophoresis coupled with LC-MS/MS.

The two most common Trichinella species present in European countries are Trichinella spiralis and Trichinella britovi. The consumption of raw or undercooked meat with invasive larvae results in trichinellosis. Currently, the most commonly used sources for detecting specific anti-Trichinella antibodies is ELISA with the muscle larvae (ML) excretory-secretory (E-S) proteins. However, these serological methods cannot be efficiently applied at early stage of infection. The aim of the current study was to identify the common and species-specific E-S proteins of T. spiralis and T. britovi adult worms which could have potential for accurate diagnosis of Trichinella infection at an early stage of invasion. Different sets of immunoreactive proteins were identified in T. spiralis and T. britovi proteomes by a combination of two-dimensional electrophoresis (2-DE), immunoblot and LC-MS/MS analysis. Polyubiquitin-B, a possible enoyl-CoA hydratase/isomerase YngF or polyubiquitin-like protein was found to be common for both species; gene ontology analysis confirmed its involvement in proteolysis, oxidation-reduction and translation processes, as well as in molecular transport. These molecules, being secreted or excreted at an early stage of parasite development, may play a critical role in the processes occurring during the initial steps of the host invasion and hence be suitable for diagnostic test development.