Colony diameters (A) and growth rates in broth (B to D) of L. pneumophila F2310 (parent) and various nudA mutants. (A) Colony diameters (±95% confidence interval) of L. pneumophila strains grown on BCYEα medium (37°C for 4 days; n = 28 for each datum point). P < 0.0001 for group comparison (one-way ANOVA); P < 0.001 for F2310 versus F2527 (ΔnudA) or F2529 (ΔnudA + pMMB2002), P < 0.001 for F2529 versus F2530 (ΔnudA + nudA in pMMB2002) or F2531 (parent + pMMB2002), and P < 0.001 for F2530 versus F2531; all other comparisons were not significant. (B) Growth of F2529, F2530, or F2531 in BYEα broth at 25°C as measured by spectroscopy in duplicate. The growth curves of F2310 and F2527 were indistinguishable from those of F2531 and F2529, respectively, and are not shown for graphical clarity. Symbols: ○, F2529; ▴ (dotted line), F2530; ⋄, F2531. (C and D) Same as panel B, including symbols, but at 37 and 42°C, respectively. A second study of broth growth gave results nearly identical to those shown in panels B to D.