Comparison of susceptibility to <i>B. microti</i> infection between inoculation with purified RBCs alone versus whole blood.

<p>RBCs were separated from whole blood of <i>B. microti</i>-infected mice by Percoll gradient centrifugation, and then mice were inoculated with either whole blood or RBCs alone. (A) Development of parasitemia in mice infected with either purified RBCs alone or whole blood. The results are expressed as the mean percent parasitemia ± the standard deviation of five mice on the indicated day after infection. Asterisks indicate statistically significant differences between mice infected with whole blood versus isolated RBCs alone. *<i>P</i><0.05 and **<i>P</i><0.01 (B) Identification of damaged or dead RBCs using Wright-Giemsa-stained blood smears. Arrows indicate damaged or dead erythrocytes caused by <i>B. microti</i> infection. (C) Comparison of spleen enlargement. All results represent ≥two independent experiments with five mice in each group.