Correlation between bioluminescence and bacterial numbers. The correlation between luminescent signals and bacteria numbers for representative serovars S. Montevideo and S. Newport. A) 96-well plate containing S. Montevideo (rows A, B, C, and D) and S. Newport (rows E, F, G, and H). 25 μl of bacteria suspension from columns 11 and 12 were spread on LB agar plates with ampicillin (100 μg ml-1) to determine the concentration of colony forming units. B) plot of bioluminescence against bacterial numbers for S. Montevideo. C) plot of bioluminescence against bacterial numbers for S. Newport.