Prevalence and first molecular-phenotypic description of Sarcocystis species in the feces of Egyptian domestic dogs (Canis familiaris)

Abstract Background Sarcocystis species are obligatorily heteroxenous protozoan parasites with predator-prey cycle. Global and national Knowledge about the epidemiology and the distribution pattern of different Sarcocystis species in dog feces are very scarce. Therefore, the current investigation was executed to declare the occurrence of Sarcocystis in the fecal specimens of the most common canids in Egypt, the domestic dogs and to recognize the species using parasitological and phenotypic approaches. Methods A total of 100 dog fecal samples were gathered and screened using sugar flotation for the presence of Sarcocystis oocysts/sporocysts. Additionally, thirty samples (30) were used for genomic DNA extraction. The 18S rRNA gene fragment was the target of primers for a PCR, followed by purification and sequencing of the amplicons. Results Currently, the results obtained appraised that 4% of fecal samples were positive for Sarcocystis spp. Under LM, the sporocysts of the canine S. tenella isolate measured 13.2–16.0 × 9.4–11 µm. Additionally, Sarcocystis spp. were verified in sixteen dogs (53.3%) using PCR and subsequent sequencing protocols. Statistically, insignificant difference in frequency of sarcocystosis relative to age and gender was noticed. Based on 18S rRNA gene, sequencing analysis of amplicons from sporocysts DNA revealed 99.82% nucleotide homology with already reported sequences of S. tenella from sheep in Iraq and Iran. Conclusions This is the first molecular evidence in support of the final host role of domestic dogs in the life cycle of S. tenella in Egypt, which provides a precious diagnostic tool for further epidemiological studies and for the assessment of the effectiveness of control measures for this disease.