Fig 1. Spo0E represses sporulation, motility, and toxin production in C. difficile.

A) Representative phase-contrast microscopy and B) sporulation frequencies of strain 630Δerm (WT) and spo0E mutant (MC1615), grown on sporulation agar for 24 h. White triangles indicate phase bright spores, and dark triangles indicate vegetative cells. Scale bar: 10 μm. C) Swimming motility of 630Δerm (WT), the spo0E mutant (MC1615), and the non-motile sigD mutant (RT1075; negative control). Active cultures were injected into soft agar and swim diameters measured daily for five days. D) Quantification of TcdA and TcdB from supernatants of 630Δerm (WT) and the spo0E mutant (MC1615) grown in TY for 24 h. The means and SD of at least three independent experiments are shown. Unpaired t-tests were performed for B-D; *P = <0.05, **P = <0.01.