Guinea Pigs Naturally Infected by Leishmania enriettii: Clinical Analyses, Parasite Isolation and Identification

ABSTRACT

Abstract Leishmania enriettii has only been found in Curitiba metropolitan region, southern Brazil were it was first observed in Cavia porcellus from the vivarium of Instituto de Biologia e Pesquisas Tecnológicas (IBPT - today named TECPAR) by Medina, 1944. Despite more than a half century from its discovery and several research articles on this species, the natural clinical signs in guinea pigs and the parasite genetic variability is still unclear. The aims of this study were to describe the clinical features, investigate the potential wild reservoirs and, in addition, we intended to understand the polymorphism trait of the species. We analyzed 26 naturally infected guinea pigs from eight Paraná state cities. All animals showed lesions compatible with leishmaniosis, such as skin nodules or ulcers on body extremities. Direct examination of the lesion samples obtained by fine-needle aspiration or punch biopsy was conducted followed by isolation and identification of parasite DNA by random amplification of polymorphic DNA (RAPD)-PCR. Through the direct exam, a large number of intracellular amastigote forms were observed in the lesions. Different strains of the parasite, isolated from the 26 animals, were grouped in 5 clusters of approximately 65% similarity. We looked for L. enriettii in other potential reservoir hosts but the parasite was not observed. These results confirm that distinct strains of L. enriettii circulate in guinea pigs from Paraná state, more specifically in the Atlantic forest region, where we believe it serves as the center for dispersion of the species.