Species identification of trichostrongyle nematodes by PCR-linked RFLP

Restriction fragment length polymorphisms (RFLP) of the second internal transcribed spacer (ITS-2) of ribosomal DNA were examined for 6 species of ruminant nematodes; Trichostrongylus colubriformis, T. axei, T. vitrinus, Haemonchus contortus, Teladorsagia circumcincta and Cooperia oncophora. The ITS-2 of each species was amplified by PCR and restricted with the endonucleases DraI, HinfI, RsaI and VspI. Using this approach, the 6 species could be distinguished. No intraspecific variation in RFLP's has been detected so far in the ITS-2 of these species, suggesting that this technique has considerable potential for the identification of eggs of different nematode species in faecal samples.