FIG 1.

CroR-dependent upregulation of pbp4(5) expression upon cell wall stress in multiple E. faecalis lineages. pbp4(5) transcript levels from cells grown to exponential-phase then treated (or not) with vancomycin were determined by qRT-PCR. Error bars represent the standard deviation of two independent cultures analyzed in triplicate; ns, not statistically significant (P > 0.05) and *, P < 0.05, as determined by an unpaired two-tailed parametric t test. E. faecalis strains were: OG1 ΔcroR, SB23; T1 ΔcroR, SB29; and CK221 ΔcroR, SB45.