Seroprevalence of Leishmania spp. in Cattle Breeds of the Mediterranean Region: Effect of the Breed in the Immune Response

: Leishmania spp. is an intracellular obligate protozoan that causes the zoonotic disease leishmaniosis. Although the dog has always been considered the main reservoir, the number of species involved in transmission of the parasite is increasingly numerous and includes both domestic species, such as cats or horses, wildlife species, and livestock such as pigs, sheep, or cows. In the latter, the presence of Leishmania spp. has been detected in some countries of South America, Asia, and Africa. In Europe, and specifically in the Mediterranean region where leishmaniasis is endemic, there are no data in this regard, although cow blood has been detected in sandflies, which act as the vector for this parasite. This study analyzed the seroprevalence of Leishmania spp. in 75 lactating cows of three different cattle breeds (Modicana, Simmental, and Holstein) from Southern Italy, finding an overall seroprevalence of 17.33%. Cytokine serum levels related to immune response were analyzed and the presence of Leishmania spp. infection did not change the levels of cytokines interleukin 1β (IL-1β), IL-6, IL-10, interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α). Interaction between breed and infection was observed, the IL-1β being higher in Modicana breed than in Simmental and Holstein when infection was present. This breed had medium levels of IL-6 without infection, with high levels being observed in Simmental and low levels in Holstein. Furthermore, Simmental cows showed higher levels of IL-6 with infection than without infection. These results suggest that the livestock species could play a relevant role in Leishmania spp. transmission in endemic regions, and with different immune responses depending on the breed. Additional research is required to ascertain the role of livestock species in parasite transmission and evaluate the immune response of autochthonous breeds.