Molecular identification of Sarcocystis cruzi and S. hirsuta sarcocysts

The present study describes PCR-RFLP based identification of Sarcocystis cruzi and S. hirsuta sarcocysts in post mortem samples of cattle from Mathura, Uttar Pradesh. 18S ribosomal gene was targeted for PCR-RFLP studies. An overall infection rate of 62.50% and 33.33% was reported for S. cruzi and S. hirsuta, respectively. A total of 10 sequences (5 apiece) were generated for S. cruzi (MN121572- MN121576) and S. hirsuta (MN121567- MN121571). The BseL I enzyme gave two restriction digests of 513 and 343 bp with S. cruzi while it gave three restriction digests of 525 bp, 241 bp and 141 bp with S. hirsuta. A total of 50 individual sarcocysts (25 each from heart and oesophagus) were characterized in the present study. All the 25 microscopic sarcocysts from heart were found to be S. cruzi. The 12 macroscopic sarcocysts from oesophagus were identified as S. hirsuta based on their characteristic restriction pattern. The other 13 microscopic sarcocysts from oesophagus gave characteristic restriction pattern identical to that of S. hirsuta (developmental stages that have not matured to appear macroscopic). The aforesaid PCR-RFLP can be routinely used for species specific identification of S. cruzi and S. hirsuta.