<i>Leishmania</i> resistant lines are more tolerant to heat shock and pH stress.

<p>Mixed promastigotes from WT and resistant lines at a 1:1 parasite ratio were incubated in culture medium, pH 5.4 at 37 ºC for 24 h. Then, mixed populations were incubated at 28 ºC and pH 7.2 and luminescence of 10⁷ promastigotes was evaluated at the first (black columns) and second (gray columns) stress cycle. Results are the average of four independent experiments ± SD. Statistically differences using Student's <i>t</i> test are showed relative to the control values (*, <i>p</i><0.05; **, <i>p</i><0.01; ***, <i>p</i><0.005; ****, <i>p</i><0.001). Horizontal line indicates the threshold at which luminescence levels have been modified with respect to control (WT+Luc).