Table 3. Competitive indices of S. Typhimurium 4/74 wild type bacteria relative to mutant bacteria in the mouse spleen.
| 4/74 wild type versus | C.I. ± STD |
| ΔglpE (6) | 0.80±0.25 |
| ΔpspE (4) | 1.14±0.03** |
| ΔpspE+pINS02 (6) | 0.72±0.47 |
| ΔglpE/ΔpspE (4) | 0.69±0.10** |
| ΔglpE/ΔpspE+pINS04 (4) | 0.97±0.25 |
C57/BL6 mice were infected i.p. with equal numbers of mutant and wild type bacteria (each 5×103 CFU). After 4 to 6 days, mice were sacrificed and the spleen was removed. Serial dilutions were spotted on LB agar plates and number of wild type and mutant bacteria in a total of 100 colonies was further determined by selection of the resistance marker. Competitive indices (C.I.) were calculated as previously described [42]. The results are shown as mean values ± STD based on the number of mice tested as indicated in brackets. Significant differences from 1.0 (**p<0.01) were determined by one-sample t-test analysis.