Figure 10From: Expression of urease by Haemophilus influenzaeduring human respiratory tract infection and role in survival in an acid environmentUrease mediates survival at acid pH. Survival of H. influenzae strain 11P6H and urease mutants at pH 4. Bacteria were suspended in buffer at pH 4 and incubated for 30 minutes at 37°C. Urea concentrations are as follows: white bars: no urea; gray bars: 50 mM urea; black bars: 100 mM. Bars indicate %survival calculated from colony counts performed at time 0 and 30 minutes. Values represent the mean of 3 independent experiments and error bars indicate standard deviation.Back to article page