Cutaneous leishmaniosis in three horses in Spain.

Blood meals from Phlebotomus perniciosus Newstead, collected in four different places in Spain, were identified to determine host-selection patterns. Blood meals were tested using a competitive enzyme-linked immunosorbent assay (ELISA) biotin-avidin method. Results indicate that this species is an opportunist that feeds on those animals to which it has easiest access. However, some preferences were indicated, because the insect never fed on chickens and frequently fed on sheep at sites where both sheep and goats were present. At some sites, the number of sand flies feeding on dogs was higher than expected, based on the proportion of dogs to man. Nevertheless, differences in host behavior, dispersal of engorged sand flies, and their exo- or endophilic habits make it difficult to assign specific host preferences.

Polymorphic DNA sequences have been amplified using different PCR-based techniques and used for species identification, strain discrimination and population genetic studies in Leishmania. A PCR fingerprinting method that uses single non-specific primers generates species-specific banding patterns with some intraspecies variation. This approach can be used to identify Leishmania species and also to discriminate strains of different Leishmania species. Cultivation of the parasites is, however, mandatory. PCR-restriction fragment length polymorphism of the internal transcribed spacer (ITS) in the ribosomal operon differentiates all Leishmania species, except members of the L. donovani and L. brasiliensis complexes. ITS-single-strand conformation polymorphism or ITS sequencing can detect strain specific-variation (except in L. infantum); culturing is not required. Species of Leishmania exhibit different degrees of genetic variation (L. tropica > L. aethiopica > L. major > L. donovani). Population analysis using co-dominant DNA markers developed by sequence-confirmed amplified region analysis revealed a primarily clonal structure in a L. donovani population from Sudan and suggested that occasional recombination events may occur in this population.