First identification of L. major in a dog in an endemic area of human cutaneous leishmaniasis in Iraq: molecular and phylogenetic studies.

Canine leishmaniasis (CanL) caused by Leishmania infantum (L. infantum) is considered as a zoonotic disease and within the last few decades, studies have identified the parasite as a major causative agent of human visceral leishmaniasis. However, in dogs, few recent studies have determined L. major as a cause of cutaneous manifestations and L. tropica as an etiological agent for cutaneous lesions involving mucosa. Interestingly, current study has found canine cutaneous lesions with mucosal involvement in a dog diagnosed with L. major, for the first time, in a focused area of human cutaneous leishmaniasis (CL) in the borderline between northern and central Iraq. Both molecular and phylogenetic studies showed that the dog L. major strain is closely related to that previously isolated from human CL in the same area. Moreover, serological study using rK39 identified IgG response against Leishmania, and the histological finding revealed the infiltration of inflammatory cells around the infection sites. These data will broaden our knowledge about CanL concerning the appearance of cutaneous clinical manifestations with mucocutaneous lesions caused by L. major. Further study on other animal reservoirs and vectors will shed the light on the epidemiology of this disease.