FIG 1.

E. faecalis enhances EHEC LEE expression. (A) A schematic of the EHEC locus of enterocyte effacement (LEE) pathogenicity island and the EHEC type III secretion system (T3SS) which it encodes. The LEE is composed of five operons, LEE1-LEE5, containing all the genes necessary for the type III secretion system apparatus. Genes of interest discussed in this work are noted below their respective LEE operons. The EHEC T3SS translocon is composed of EspA, which forms the filament, and EspB and EspD that form a pore in the target cell membrane through which effector proteins, such as Tir, are injected into host cells. IM, inner membrane; OM, outer membrane. (B) EHEC was grown alone or in coculture with E. faecalis strain V583 in 1 g/liter glucose with DMEM, and the transcription of the indicated EHEC virulence genes was quantified via qPCR. Virulence genes were normalized to rpoA levels, and results are expressed as fold change compared to the levels with EHEC alone. The average and standard deviation of four replicate samples are plotted, and a two-tailed t test was performed to determine significant differences compared to results with EHEC alone. *, P < 0.05; **, P < 0.01.