RFLP Analysis of Fragments of the 18S rRNA and Cox1 Genes to Identify Sarcocystis cruzi in Water Buffalo (Bubalus bubalis) In Guilan Province, North of Iran

Background: Sarcocystosis is a zoonotic disease worldwide caused by Sarcocystis spp., some of these species can show clinical and subclinical manifestations, resulting in financial losses. Our study was performed for identifying Sarcocystis sp., in slaughtered buffalo by PCR–RFLP based strategy with sequencing in Guilan, North of Iran. Methods: Overall, 400 fresh muscle samples were prepared via naked-eye observation from 100 buffaloes (esophagus, diaphragm, shoulder, and thigh), followed by the digestion of samples. The PCR was done to amplify partial parts of the 18S rRNA and mitochondrial cytochrome c oxidase subunit I (Cox1) genes. Then, the PCR products were digested by endonuclease SspI, DraI, and FokI. Sequencing of all species was done to confirm the RFLP results. Results: Five macroscopic cysts (1.25%) were visible in the sample by naked-eye examination. Furthermore, 293 samples (73.25%) were found to be Sarcocystis sp. positive through tissue digestion and microscopic observation, whereas 376 samples (94%) were positive by PCR. In addition, the findings of PCR-RFLP and nucleotide sequence samples exhibited the infection of buffaloes with S. cruzi. Conclusion: Based on the data presented herein, Bovine sarcocystosis caused by S. cruzi is very common in buffalo in the Guilan region. Regarding the high prevalence of sarcocystosis, developing disease control and prevention policies for buffaloes is necessary, and a change of attitude in traditional farming is recommended.