Analysis of the specific genes within the IFN signaling pathway that were differentially perturbed in the blood of WT versus Ifnar1-/- infected mice showed that some genes such as Oas1 and Ifit3 were completely dependent on type I IFN at all time points, regardless of the bacterial load (Fig 3A) since their expression was higher in the infected WT than the infected Ifnar1-/- mice at all time-points post infection (Fig 4D). This evidence concerns the gene IFNA1 and infection.