NKCC1 is required for enteric C rodentium infection clearance. NKCC1WT/WT, NKCC1WT/DFX, and NKCC1DFX/DFX mice were infected with 109 colony forming units of a kanamycin-resistant strain of C rodentium. Feces were collected every day, eluted, plated, and bacteria were enumerated. (A) Percentage of NKCC1WT/WT, NKCC1WT/DFX, and NKCC1DFX/DFX mice with positive C rodentium shedding in feces over the 9-day period. (B) Bacteria plated on a kanamycin-containing plate show colonization or delay clearance in NKCC1WT/DFX and NKCC1DFX/DFX mice. (C) Inflammatory cytokine production in the serum of NKCC1WT/WT, NKCC1WT/DFX, and NKKCC1DFX/DFX mice after 9 days postinfection (n = 3–5 mice per group, the experiment was repeated twice). hets, heterozygotes; homos, homozygotes; IL, interleukin; INF, interferon.