Prevalence and molecular characterization of Sarcocystis species in water buffaloes (Bubalus bubalus) in Egypt.

The present study was planned to investigate the prevalence of Sarcocystis spp. among slaughtered water buffaloes (Bubalus bubalis) at Alexandria province, Egypt. Three hundred blood samples were collected from slaughtered buffaloes (5-7 years old). Two techniques were used to evaluate the seroprevalence of Sarcocystis spp., enzyme-linked immunosorbent assay (ELISA) and indirect haemagglutination assay (IHA). It was revealed that 203 (67.6 %) and 191 (63.6 %) of the tested serum samples were seropositive to Sarcocystis spp. by ELISA and IHA, respectively. The results of sensitivity and specificity of IHA relative to ELISA were 94 and 100 %, respectively. For molecular characterization of inter- and intra-species genetic polymorphism within Egyptian isolates of Sarcocystis spp. of water buffaloes, polymerase chain reaction (PCR) and polymerase chain reaction-restriction length polymorphisms (PCR-RFLPs) were performed on four macroscopic isolates. The isolates represented two different geographical regions of Egypt, Alexandria and Assuit provinces. Alexandria isolates (large and small-sized cyst of the same host) and Assuit isolates (large and small-sized cyst of the same host) were used. The 18S rDNA of the macroscopic cysts were characterized, in tandem, by four restriction endonucleases, RsaI, MboI, SspI and DraI. RsaI and MboI enzymes did not show any restriction sites for all isolates, leaving the amplified fragments without cutting. SspI showed two fragments in Alexandria and Assuit small-sized isolates cut by the enzyme at 600-700-bp fragments, while Alexandria and Assuit large-sized cysts amplicons were not digested by this enzyme. The fourth enzyme, DraI, cut the PCR product of Alexandria large-sized cysts into two fragments (420-780 bp), while Assuit large-sized amplicon was not cut. It could be concluded that there was a far distance between the two local isolates (small and large sized), but there were no differences between the large-sized isolates.