FIG 4.

Expression of putative cation transporter genes during infection of hamster model. To determine the expression of Fur-repressed genes during a C. difficile infection, hamsters were infected with 10,000 wild-type spores 5 days after receiving a single dose of clindamycin. Two days after the initial onset of diarrhea, infected hamsters were sacrificed. The ceca of infected hamsters were removed, and RNA was extracted from the cecal samples. The mRNA levels of cd0591, zupT, fpi, cd2992, fhu, feo1, feo2, and feo3 were normalized to the level of mldA transcript in each sample using the primers listed in Table S1 in the supplemental material. The mRNA levels were compared to those in wild-type cells grown in high-iron (250 μM FeCl₃) TY and low-iron (100 μM dipyridyl) TY. Experiments were performed in technical and biological triplicate. The data are graphed as the arithmetic mean with standard deviation.