In both co-infections with a WT strain (Fig 5A and 5B) and in single-strain infections (Fig 5C and 5D), the ΔdusB-fis mutant colonized tissue sites and grew for the first 24 hours post-infection with kinetics similar to WT Yptb. However, by 48 hours post-infection, the level of ΔdusB-fis failed to increase as rapidly as WT, indicating that the growth of this strain was not restricted until after initial seeding and expansion in tissue sites. The gene discussed is LINC01554; the disease is coinfection.