FIG. 6.
(A) Kinetics of transcription of the PM0298-PM0299-hgbA operon in mice inoculated intraperitoneally with the P. multocida PM1077 strain, measured as the proportion of Cms bacteria recovered from the peritoneal cavity (♦). The absence of Cms bacteria in cultures of the P. multocida PM1077 strain growing in BPW medium without chloramphenicol demonstrates the genetic stability of the construction (▪). Three animals were used for each point, and each Cms percentage is the average of three determinations for each of the inoculated mice. In all cases, the standard error of any value was never greater than 10%. (B) Kinetics of transcription of the PM0298-PM0299-hgbA operon in the P. multocida PM1077 strain measured in vitro as the proportion of Cms bacteria recovered from BPW medium (•) or BPW medium supplemented with either DPD (50 μg/ml) (♦), DPD and FeSO4 (1 mM) (▴), or DPD and hemoglobin (40 mM) (▪). All values are the means of at least three experiments (each performed in triplicate), and the standard error of any value was never greater than 10%.