Molecular recognition and phylogenetic tree analysis of Cystoisospora canis in stray dogs in Diwaniyah city, Iraq

Cystoisospora spp. are Apicomplexa parasites, protozoan parasites with a global prevalence of 1-5% in dogs. The current study aimed at finding out about the presence and molecular features of Cystoisospora among homeless dogs in Al-Diwaniyah province in Iraq. The 200 fecal samples from street dogs from various regions were floated, sedimented and then tested by direct smear. We identified molecularly using PCR from the 18S rRNA gene and sequenced and phylogenetic. A 19% prevalence of Cystoisospora spp. was observed under microscope, the province’s first known case of the parasite. In our infection dogs, the infection rates were higher in females 22.34% than males 16.03%. Younger dogs (puppies) were much more common with prevalence at 38.02%, compared with 8.52% for the older dogs. Cystoisospora DNA was found in 56% (17/30) of the specimens by PCR. Sequence alignment of the 511 bp region of the 18S rRNA gene identified 100% identity with Cystoisospora canis strains already in GenBank from Canada. The strains in locality were identified as Cystoisospora canis by phylogenetic recognition including Unweighted Pair Group Method with Arithmetic Mean (UPGMA). The molecular phylogenetic data from this research on Cystoisospora canis in Iraqi street dogs represents the first such molecular phylogenetic data on this parasite in Iraq and adds to the epidemiology of this parasite in Iraq.