Figure 4
Effects of priA inactivation on meningococcal growth. (A) Growth curves of B1940 and B1940ΩpriA in liquid GC medium. (B and C) Viability of meningococcal cells as determined by CFU method. Serial dilutions (10-2 to 10-6) of B1940, B1940ΩpriA and B1940ΩpriA/priA+ cultures in liquid GC medium were plated on either GC agar or GC agar containing 5 mM sodium nitrite and incubated aerobically in the presence of 5% CO2; parallel dilutions were plated on GC agar containing 5 mM sodium nitrite and incubated under oxygen-limiting conditions. CFU were determined after 24 h. Viability of B1940 grown aerobically is arbitrarily assumed equal to 1.0. Data are shown as mean ± standard deviation from five independent experiments, each with triplicate samples. The Student's T-test was used for statistical analysis. Statistically significant differences between values from B1940 (or B1940ΩpriA/priA+) and B1940ΩpriA (asterisks) are declared at a p value < 0.05. Note in C the small colony size and the reduced colony number of the priA-defective mutant compared to the wild type and complemented strains.