Relative expression of cadA in 1% and 3% NaCl and at pH 7 and pH 5. Wild-type V. parahaemolyticus RIMD2210633 was grown for 4 h prior to RNA extraction under the following conditions: (i) LB with 3% NaCl at pH 7, (ii) LB with 3% NaCl at pH 7 plus an additional 30 min at pH 5, (iii) LB with 1% NaCl at pH 7, and (iv) LB with 1% NaCl at pH 7 plus an additional 30 min at pH 5. Bars represent expression levels of cadA normalized to 16S rRNA and relative to the expression levels found in V. parahaemolyticus grown in LB with 3% NaCl at pH 7 as determined by use of qPCR. RNA was extracted on at least two separate occasions for all of the conditions examined, and qPCR was carried out in duplicate for each gene. Error bars indicate standard deviations. An unpaired Student t test was used to determine statistical differences between results for LB with 3% NaCl at pH 5 and those for LB with 1% NaCl at pH 5. *, P < 0.01.