Iron chelators limit the growth of Chlamydia by reducing intracellular iron. Macrophages from flatiron mice were grown in the presence (+) or absence (−) of FAC for 18 hours. Cells were infected with C psittaci for 2 hours, extracellular bacteria removed, and cells incubated in the presence of DFO, desferasirox, deferriprone, or desferasirox that was preincubated with 10 to 100 μM iron as FAC (+/+). Twenty-four hours after infection, cells were processed for immunofluorescence and large and small inclusions quantified as in Figure 1 (A), lysed for ferritin analysis as in Figure 5 (B), or lysed for RT-PCR analysis of C psittaci genes omcB, lcrH-1, and rs16 (C) as described in “Other procedures.” Error bars represent the standard deviation of the mean.