Figure 2.

VvPlpA is essential for pathogenesis of V. vulnificus. A, the wild type grown to an A₆₀₀ of 0.5 was exposed to either LBS or blood of uninfected mice (n = 3) for 1 or 2 h and then used to isolate total RNAs. The plpA mRNA was determined by real-time qPCR analyses, and the plpA mRNA level in the bacteria exposed to LBS was set as 1. B, 7-week-old female ICR mice (n = 15 per group), injected intraperitoneally with iron-dextran, were intragastrically infected with the wild type and plpA mutant at doses of 10⁸ cfu. C–F, the mice, without an iron-dextran administration, were intraperitoneally infected with the wild type (n = 11), plpA mutant (n = 11), or PBS (n = 5, control) at doses of 10⁶ cfu and then sacrificed to obtain blood at 4 h postinfection. C, the number of either the wild type or plpA mutant in the blood of infected mice (n = 6 per group) was enumerated as cfu/100 μl of blood. Each open symbol represents an individual mouse. Black-filled inverted triangles indicate median values. D–F, the levels of MPXI (D), ALB (E), and AST/ALT (F) in the wild type– or plpA mutant–infected or PBS-treated mice (n = 5 per group) were determined by hematological analyses. Error bars, S.D. Statistical significance was determined by Student's t test for A and C–F, and by log-rank test for B. *, p < 0.05; **, p < 0.005; ns, not significant. WT, wild type; plpA, plpA mutant; PBS, control.