<i>T</i>. <i>cruzi</i> needs a signal provided by ROS to multiply efficiently.

<p><b>(A)</b> Inflammatory macrophages obtained from Phox KO and C57BL/6 WT mice were incubated with 1mM of N-acetyl-cysteine (NAC) and 100μM H₂O₂ 2 hours before the infection with different parasites. Cells were washed to remove extracellular parasites and either fixed or re-incubated with medium or medium plus NAC or H₂O₂ for different times. The slides were stained and counted to determine the infection index. <b>(B)</b> Inflammatory macrophages from C57BL/6 WT and Phox KO mice were infected with CL Brenner strain of <i>T</i>. <i>cruzi</i> previously treated with 50μM H₂O₂ for 30 minutes. Cells were washed to remove extracellular parasites and either fixed or re-incubated with medium. The slides were stained and counted to determine the infection index. Data shown are representative one of three independent experiments performed in triplicate. A minimum of 200 macrophages were counted per group in triplicate. All data are presents as the means ± standard deviation. * indicates significant differences between marked bars or points, p<0.05, two-way ANOVA test with Bonferroni post-test.