Beyond reptiles: the fire salamander as a potential host for Leishmania (Sauroleishmania) tarentolae

<i>Leishmania</i> parasites are dixenous protozoans transmitted by phlebotomine sand flies and known to infect a range of vertebrate hosts, including mammals, birds, and reptiles. However, to date, there is only a single record for amphibians, in a toad (order Anura), based on molecular evidence. In this study, we present the first evidence supporting the potential of <i>Leishmania</i> to infect an amphibian host, the fire salamander (order Urodela), through combined molecular and morphological approaches. A total of 78 salamanders were sampled from a protected area in northern Italy. Single cells morphologically similar to <i>Leishmania</i> were observed in 4.48 % of Giemsa-stained blood smears. <i>Leishmania</i>-specific qPCR coupled with high-resolution melting (HRM) analysis detected parasite DNA in 7.14 % of blood samples and 12.12 % of cloacal swabs. Sanger sequencing of a qPCR-positive sample and phylogenetic analysis identified the parasite <i>as Leishmania (Sauroleishmania) tarentolae</i>. These findings may contribute to expand the known host range of <i>Leishmania</i> to include Urodelan amphibians, suggesting that these vertebrates may play an unrecognized role in the ecology and transmission dynamics of these parasites.