Characterization of porcine and ovine Oesophagostomum spp. by isoenzymatic patterns and restriction-fragment-length polymorphisms (RFLPs).

Four different morphological and biometrical populations of Oesophagostomum have been identified, using classical taxonomy methods, from Sus scrofa domestica (pigs): O. dentatum (Od), O. quadrispinulatum (Oq), O. granatensis (Og), and a fourth population, including individuals with morphological and biometric parameters overlapping these three species that were clasified as Oesophagostomum sp. The G6PD and MDH isoenzymatic patterns did not discriminate between the three species, while GPI showed a diagnostic isoenzymatic pattern for Oq. Og showed identical G6PD, GPI and MDH isoenzymatic pattern as Od. Furthermore, after rDNA amplification by polymerase chain reaction (PCR), the uncut PCR product showed that the ITS2 of these three species had a similar size of 320 base pairs (bp). Restriction-fragment-length polymorphisms (RFLP) were analyzed after digestion of the ITS2 with 13 different restriction enzymes. After electrophoretic separation of the digested PCR products, only one unique differentiating pattern of bands was observed for Od and Oq. This was when Sau3AI was used, while Og showed an identical band pattern to Od. Thus, our studies provided no evidence for the existence of Og and Od as differentiated populations. O. venulosum was isolated from sheep and goat; G6PD and MDH isoenzymatic patterns discriminated this species from porcine species of Oesophagostomum. The ITS2 region appeared as a different band of 380 bp from those observed for porcine Oesophagostomum species.