FIG. 2.

Growth and survival of wild-type BCG and ΔdosR::km, ΔdosR::km(pCB4), and ΔRv3132c::km strains in the Wayne dormancy culture system. Exponentially growing cultures were diluted and grown in sealed tubes with stirring. (A) Growth monitored by turbidity measurement. (B) Growth monitored by colony count determination. wt, wild type; ΔdosR::km, dosR gene replacement mutant; ΔdosR::km(pCB4), ΔdosR::km mutant transformed with the dosR rescue plasmid pCB4; ΔRv3132c::km, Rv3132c gene replacement mutant (see Fig. 1A). Growth and survival of ΔdosR::km transformed with pNBV1, i.e., the vector backbone used to carry the dosR genomic fragment in the pCB4 rescue construct (Fig. 1A), was indistinguishable from the behavior of the untransformed ΔdosR::km strain (data not shown). The experiments were carried out three times with duplicate cultures. Standard deviations are shown. The arrow pointing upwards indicates the time at which samples were taken for the protein analyses shown in Fig. 3. f and d, fading and complete decolorization of the oxygen indicator methylene blue, respectively.