Molecular Detection of Neospora Caninum in Different Tissues of Dogs and Cats in Shiraz, Iran

ABSTRACT Background Neospora caninum is one of the most significant causative agents of abortion in dairy cattle. Canids, especially dogs, act as definitive hosts and cattle serve as intermediate hosts for these coccidian protozoa, which can cause neuromuscular disease in dogs. The objective of this study was to determine the molecular characterisation of N. caninum in different tissues of dogs and cats in Shiraz, Southern Iran. Methods A total of 684 samples were collected from various tissues of 28 dogs and 29 cats during 2015–2016. Genomic DNA from the 684 samples was extracted manually using the phenol‐chloroform method, and the NC5 gene was amplified by polymerase chain reaction (PCR), using specific primers for Neospora (Np21plus and Np6plus). Subsequently, PCR products from 4 samples were sequenced. BioEdit software was utilised to align the sequences and compare them to previously published sequences in GenBank. Phylogenetic analysis was conducted using the Mega 5.0 software and the maximum likelihood method was employed to conduct phylogenetic analysis. Results Four out of 684 samples (0.58%) tested positive when compared with controls (2 samples from duodenum and ileum tissues of 2 dogs and 2 samples from the same tissues of 2 cats). All positive samples were confirmed as N. caninum through analysis of the NC5 gene sequence. Sequence comparison revealed no differences among the nucleotide sequences of the N. caninum isolates. Additionally, the sequences of N. caninum were identical and showed 100% similarity. Conclusion This study confirmed the presence of N. caninum in dogs and cats in rural regions of Shiraz, the capital of Fars province, Southern Iran. Further studies are recommended to expand on the findings of this study regarding neosporosis in this area.