All experiments were repeated three times. E. coli counts were
transformed to log10 values. Means for triplicate log E. coli counts
were plotted against means for triplicate cycle threshold (Ct) values
obtained by real-time PCR. Regression lines were fitted to the plots
using Microsoft Excel 2007. Differences in mean Ct values were
separated using a paired t-test in Minitab, version 6 (Microsoft,
Redmond, WA, USA).