Differentiation of Trichinella isolates by polymerase chain reaction.

Oligonucleotide primers were synthesized for the polymerase-chain-reaction amplification of target DNA from two sequences ofTrichinella spiralis. Six strains belonging toT. spiralis, T. nativa, T. britovi, T. pseudospiralis, andT. nelsoni were tested. Amplification products were obtained withT. spiralis, T. britovi, andT. nelsoni DNA from a 53-kDa antigen cDNA sequence and withT. spiralis andT. nelsoni DNA from a 1.6-kb repetitive DNA sequence. Differences in the length of the amplification products obtained from the repetitive sequence would enable a differentiation betweenT. spiralis andT. nelsoni, suggesting that the 1.6 kb repetitive DNA sequence would not be specific forT. spiralis. No amplification was detected forT. nativa orT. pseudospiralis DNA from the two sequences and forT. britovi DNA from the 1.6-kb repetitive DNA sequence.