TABLE 1.

Chelation of intracellular free iron with DfX halts C. burnetii proliferation^a

Cells	J774A.1 (106)/well		C. b./J774A.1 cell		C. b. (106)/well
	24 h	72 h	24 h	72 h	24 h	72 h
Infected
0 μM DfX	3.3 ± 1.1	14.0 ± 3.0	10.4 ± 2.5	15.5 ± 2.4	3.4 ± 0.9	21.6 ± 6.2
20 μM DfX	4.9 ± 2.6	12.0 ± 1.9	9.5 ± 1.7	13.4 ± 2.3	4.6 ± 0.8	16.0 ± 4.4
100 μM DfX	4.2 ± 0.2	6.9 ± 0.7	14.5 ± 0.5	5.3 ± 3.4	6.0 ± 0.2	3.8 ± 2.6
Uninfected
0 μM DfX	4.5 ± 0.6	15 ± 0.6	NA	NA	NA	NA
20 μM DfX	5.5 ± 1.3	11 ± 2.2	NA	NA	NA	NA
100 μM DfX	4.8 ± 0.9	6.3 ± 1.0	NA	NA	NA	NA

^aJ774A.1 cells in 24-well plates were infected with C. burnetii (C. b.) and simultaneously incubated in 0, 20, or 100 μM DfX. Three wells for each treatment were harvested at 24 h, and six wells were harvested at 72 h. The number and viability of J774A.1 cells per well were determined by hemocytometer. Infected J774A.1 cells were mounted on slides, and C. burnetii was visualized by Gimenez stain and counted on each slide. C. burnetii per well was calculated by multiplying C. burnetii per J774A.1 cell by J774A.1 cells per well for each well harvested. Viability of J774A.1 cells remained above 80% for all samples. Results are means ± standard deviations. NA, not applicable.