Fig 6.

Growth rate dependence of AFN-1252 on virulence factor and fabH mRNA levels. Strain Wood46 was subjected to treatment with AFN-1252 (50 ng/ml) for 15 min either during the logarithmic phase of growth (OD₆₀₀, 0.45) or after growth slowed as the cells began to enter stationary phase (OD₆₀₀, 2.2). Transcript abundance in triplicate samples was measured in triplicate by qRT-PCR using gmk as the calibrator. (A) mRNA levels detected at an OD₆₀₀ of 0.45 were set to 1.0 and compared to the same measurements at an OD₆₀₀ of 2.2. fabH mRNA was significantly decreased in the samples at the OD₆₀₀ of 2.2 (*, P < 0.05). mRNA levels for the 4 virulence factors were either unchanged (hlgC) or modestly elevated (∼2-fold) with ehp, efb, and saeP. (B) mRNA levels before AFN-1252 treatment were normalized to 1, and the changes in virulence factor and fabH mRNAs triggered by AFN-1252 are plotted. There was no significant difference between virulence gene expression in cells treated with AFN-1252 at an OD₆₀₀ of 2.2, but all 4 virulence factors were decreased by about an order of magnitude in cells treated with AFN-1252 at an OD₆₀₀ of 0.45 (*, P < 0.05). fabH mRNAs were significantly increased in response to AFN-1252 under both experimental conditions (*, P < 0.05). Significance between treated and untreated samples was calculated using the Student t test, and error bars indicate standard deviations.