KRT1 and Sepsis: A previous study that compared the virulence of ST131 and non-ST131 clinical isolates by using the same murine sepsis model as used here showed that the presence of certain genes (i.e., papAH, kpsMII, papGIII, vat, K1, and clbB/N), rather than ST131 status, was associated with higher lethality [9].