FIG. 5.

Growth of the ive gene mutants showing decreased virulence in HeLa cell lysates. The mutant strains of pyrH, hlyU, and purH homologues were inoculated into 2.5% NaCl HI (A), DMEM (B), and HeLa cell lysate (C) and then cultured for 3 h at 37°C in a 5% CO₂ incubator. Viable cells were counted every 1 h on 2.5% NaCl HI agar plates. Growth of the mutants in HI broth, DMEM, and HeLa lysates was compared to that of appropriate isogenic WT strains MO6-24/O (pyrH and hlyU) or CMCP6 (purH). The error bar indicates the standard error of the mean from triplicate experiments.