FIG 6.

Expression of luciferase by Y2::luxAB-infected E. amylovora CFBP 1430 cells grown under different conditions. (A) Temperature and time dependency. Cells of E. amylovora CFBP 1430 were grown in LB broth (●) or LB broth supplemented with depolymerase (○) and infected with Y2::luxAB. The expression of luciferase was measured at regular intervals, and the mean values of three independent experiments ± the SD are displayed. (B) Sensitivity of Y2::luxAB-based detection. A dilution series of E. amylovora CFBP 1430 was infected with Y2::luxAB, and the light emission was measured after 50 min. Mean values of three independent experiments ± the SD are displayed and are compared to controls with bacteria only. The background levels were generally around 100 RLU (horizontal line), and asterisks indicate a significant increase compared to the uninfected control (P < 0.05; Student t test).