Characterization of Spanish Trichinella isolates by random amplified polymorphic DNA (RAPD).

The random amplified polymorphic DNA (RAPD) assay was used to find molecular markers able to distinguish Trichinella spiralis from T. britovi, the two recognized Spanish Trichinella species. Fourteen Spanish Trichinella isolates, as well as reference Trichinella isolates representing the five species T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4) and T. nelsoni (T7) and the three other taxa Trichinella T5, Trichinella T6 and Trichinella T8 of the genus, were characterized by RAPD using both purified and crude DNAs from infective muscle larvae (ML) and seven arbitrary primers. Three primers yielded diagnostic RAPD markers for the Spanish T. spiralis and T. britovi isolates as well as for the Trichinella reference isolates analysed, and in the case of crude DNAs the results were obtained in few hours. In addition, the species-specificity of the diagnostic RAPD markers from Spanish Trichinella isolates was studied by cross-hybridization assays. These assays confirmed that the selected diagnostic DNA fragments were not species-specific, but showed potential differences in the copy number among the examined Trichinella genetic clusters.