Fig. 2.

(A) Dose–effect of antimonyl tartrate (Sb^III) on the growth of L. braziliensis strains PER104 and PER002 transfected with cosmid pcosTL or pcosC1.6 respectively. Growth at 0 μM Sb^III was defined as 100%. The dashed arrows indicate the 50% inhibiting concentration (IC₅₀). Significance (IC₅₀): p = 0.002, n = 6. (B) Effect of pcosC1.6 in L. infantum. Empty vector pcosTL and cosmid pcosC1.6 were transfected into L. infantum and selected under G418. Cells of both recombinant populations (5 × 10⁵ cells ml⁻¹) were grown under the indicated Sb^III concentrations for 72 h. The diagram shows the cell density after 72 h relative to the control culture (0 μM Sb^III). Numerical IC₅₀ values are indicated. Significance (IC₅₀) p = 0.016, n = 5. (C) Constructs pcos-210, pcos-220, and the empty vector pcosTL were transfected into L. infantum and selected under G418. Cells of each recombinant population (5 × 10⁵ cells ml⁻¹) were challenged with the indicated Sb^III concentrations for 72 h. The diagram shows the cell density after 72 h relative to the control culture (0 μM Sb^III). The bars indicate the mean error. Significance (IC₅₀) p = 0.008, n = 5. (D) Control of LbrM20.0210 expression by qPCR. Expression mediated by cosmid pcosC1.6 was given the value 1. Note that L. infantum expresses a homologous gene that is not amplified by the species-specific primers. Thus, the degree of overexpression cannot be determined. (E) Quantification of LbrM20.0210 expression in L. braziliensis strains PER002[pcosTL] and PER002cl7[pcosC1.6]. Expression in the control strain PER002cl7[pcosTL] was assigned the value 1. n = 6. The standard error of means is depicted.