(A–E) B6.WT and B6.∆Naip (green) mice (lacking expression of all Naip genes) treated orally with 25 mg streptomycin sulfate were orally challenged the next day with 5x107 CFU of WT or BS103 ('B', non-invasive) Shigella. Endpoint harvests were performed at 48 hr post-infection (p.i.). Here, NAIP is linked to infection.