FIG 4.

Gluconeogenic capacity is necessary for C. burnetii amphotropic fitness. Intracellular growth of the Pt, CbΔpckA, and CbΔpckA::pckA strains were compared during infection of J774A.1 (A), JEG-3 (B), THP-1 (C), and VERO (D) cells cultured in IFmM (blue) or RPMI (gray). Replication was determined via quantification of GE every 2 days for 8 days. Depicted data illustrate means ± SEM (n = 3 to 6). Asterisks in blue and gray indicate differences between the Pt and CbΔpckA strains during infection of host cells cultured in IFmM or RPMI, respectively. *, P < 0.05; **, P < 0.01 (unpaired Student's t test). Brackets indicate the change in final (i.e., day 8) yields between the Pt and CbΔpckA strains.