Morphological Description, Phylogenetic and Molecular Analysis of Dirofilaria immitis Isolated from Dogs in the Northwest of Iran

Dirofilariasis is a globally distributed arthropod-borne parasitic disease of mainly canids and felids. We evaluated to extend the knowledge of morpho-molecular characteristics and outer ultrastructure of isolated from Northwest of Iran. Overall, 67 filarial worms including 41 females and 26 males parasites were collected from the cardiovascular system of the 43 stray dogs in Meshkinshar, Ardebil Province, Northwest of Iran in 2017, and subjected to light and scanning electron microscopy (SEM) as well as carmine alum staining for morpho-molecular and identification. Molecular methods were used for confirmation of morphological findings by sequencing of Cyto-chrome c oxidase subunit I ( ) gene. The partial DNA sequencing of gene of adult parasites showed considerable homology and close proximity to the previously isolated from Kerman and Meshkinshahr, Iran. The lowest genetic variation and the highest intra-species variability was found in and , respectively. No similarity was identified between nucleotide sequence and species as its endosymbiont bacteria. The SEM technique is an excellent tool for differential recognition of the parasite surface morphology and molecular techniques could differentiate and identify spp.