PCR-based differentiation of three porcine Eimeria species and Isospora suis

Isospora saris and Eimeria are frequent coccidian parasites of pigs. The un sporulated oocysts of Eimeria species and of I. suis are difficult to diffe rentiate. Therefore, a species-specific PCR was developed. PCR products wer e amplified from Eimeria polita, Eimeria porci, and Eimeria scabra using pr imers from the conserved 18S rRNA regions and were subsequently sequenced. Based on variable sequence regions, primers were constructed for the differ entiation of the three Eimeria species and I. suis. Using a combination of PCRs detecting one or two species; all four coccidian species were detected (theoretical lower detection level: DNA content of 250 oocysts of each Eim eria species or 25 oocysts of Isosopora in 1 mul) and differentiated. The P CR-based differentiation of the above mentioned species provides a useful a lternative to microscopy. (C) 2001 Elsevier Science B.V. All rights reserve d.