FIG. 5.

Effect of nudA transcomplementation on growth within guinea pig alveolar macrophages. Bacterial strains F2531 (parent + pMMB2002), and F2529 (ΔnudA + pMMB2002) or F2530 (ΔnudA + nudA in pMMB2002) were mixed together before the bacteria were added to the macrophages. The data were pooled from two independent experiments, were normalized, and are represented as the mean ratios of either F2531 to F2529 or F2531 to F2530. Error bars represent standard error of the mean (n = 6). P ≤ 0.002 for F2531/F2530 versus F2531/F2529 ratios on days 2 and 3 (P = 0.3 for day 1, all by nonpaired t tests). The inset shows the growth of F2531 alone in macrophages. Note that a lower ratio indicates greater virulence of the strain in reference to that of F2531 and that a ratio of 1 would mean virulence equivalent to F2531. One other set of experiments gave similar results. Symbols: ▪, F2531:F2529; ▿, F2531:F2530.