FIG 7.
β-Galactosidase activities expressed from CiaR-regulated promoters and cell morphology of S. pneumoniae R6 derivatives carrying the ciaH232 allele. (A) Strains were grown in C+Y medium. β-Galactosidase activities were determined at three different time points and are given in nanomoles of nitrophenol produced per minute and milligram of protein. Mean values and standard deviations from three independent experiments are presented. The activities of the CiaR-dependent promoters in the R62x1aC strain were significantly different (P < 0.05) from those of the promoters in the other strains. The promoters and relevant genetic markers are indicated. (B) Phase-contrast images taken at the mid-exponential growth phase. The strains were grown in C+Y medium. Arrows, altered cell morphology. Bar, 5 μm.