Fig. 4.

Biotin rescues the ∆FTN_0818 virulence defect in vivo. (A) Mice were infected s.c. with a 1:1 mixture of WT with the ΔFTN_0818 or the ΔFTN_0818 complemented strain (ΔFTN_0818-COMP). At 48 h pi, spleens were harvested to quantify bacterial levels, and the CI was calculated. (B and C) Mice were s.c. infected with 10⁶ cfu of WT or ΔFTN_0818. At 48 h pi, the spleen (B) and skin at the site of infection (C) were harvested and bacterial levels quantified. (D) A competition assay was performed with WT and ΔFTN_0818 in the absence of biotin or WT and the ΔFTN_0818 complemented strain in the presence of biotin. At 24 h pi, the skin at the site of infection was harvested to quantify bacterial levels, and the CI was calculated. *P < 0.05; **P < 0.001; ***P < 0.0001.