Figure 3. MgtC can restore the WT phenotype in a SPI-3 mutant strain.

Strains WT (STH2370 wild type), ΔSPI-3 (SPI-3⁻), ΔSPI-3/pBmgtC (mgtC ⁺) and ΔSPI-3/pBBR-5 (SPI-3⁻). (A) For growth in 10 µM MgCl₂ strains were incubated in M9 minimal medium and the OD₆₀₀ was measured at the indicated times. (B) U937 cells were infected at a MOI of 50∶1. Colonies were counted at time 2 h and 24 h and expressed as a percentage of intracellular survival. Values represent the mean of at least three independent experiments ±SD (*p<0.05).