Fig 3.
Intranasal infection of C57BL/6 mice with Y. pestis usher deletion mutants. Mice were infected with WT KIM5+ or usher deletion mutants via the intranasal route with 4 to 5 LD50 (2,000 to 2,500 CFU), and the time to death was recorded. Mice were monitored for signs of illness or death for 21 days. Each graph represents the combined data from three separate experiments with 5 mice each for a total of 15 mice per strain. Mice infected with deletion mutants Δy0350, Δy1858, or Δy1871 were significantly attenuated (*, P < 0.05; ***, P < 0.001) compared to mice infected with the WT strain.