FIG 8.

Effect of the disruption of mbtS on the staphylococcal virulence in a murine model of blood infection (A) and skin infection (B and C). (A) An equal amount of the test strains was administered to 10 C57BL/6J mice via the retro-orbital route, and then the mice were watched for 2 weeks. The statistical significance was measured by the log rank (Mantel-Cox) test. ***, P < 0.001; ****, P < 0.0001. (B and C) An equal amount of the test strains was injected s.c. into the right flanks of eight C57BL/6J mice. At day 2 postinfection, the lesion size was measured (B), and the bacterial CFU in the infected skin tissue was determined (C). The statistical significance was measured by an unpaired, two-tailed Student t test. **, P < 0.005; n.s., not significant. WT, wild-type strain USA300; mbtS, USA300 with a transposon insertion in mbtS; ΔftsH, ftsH deletion mutant of USA300; ΔftsH::mbtS, ΔftsH mutant with a transposon insertion in mbtS.