Fig 1. Quantification of parasite load in spleen samples from dogs naturally infected with Leishmania infantum.

Quantification was carried out using real time PCR with primers specific for a Leishmania sp. DNA sequence of the small subunit ribosomal RNA (ssrRNA). The canine HPRT gene was used in order to normalize initial concentrations of DNA in each sample. (A) Histogram and normal density lines of L. infantum infected animals classified into low (n = 46), red line, or high (n = 42), green line, parasite load by the fitting of an optimum number of mixtures of normal distributions. (B) Minimum and maximum values of parasite per 10⁶ canine cells. Each sample was quantified in duplicate for each target. a,b Statistically significant differences (p < 0.0001, Unpaired T-test).