FIG 6.

Inhibition of nitrate in the gut during oral infection increases csgD expression and curli production. (A) Female C57BL/6 mice (6 to 8 weeks of age) were pretreated with streptomycin and then inoculated orally with 10⁸ CFU of S. Typhimurium csgD::luxCDABE strain. One group of mice was given AG in their drinking water ad libitum. Animals were euthanized 96 h postinfection. csgD expression in the intestinal tract, spleen, and liver were measured as light production using an IVIS spectrum imaging system (Perkin Elmer). Each panel shows organs from a different mouse. (B) Luminescence in colon, cecum, and small intestine of individual mice left untreated or treated with AG quantified using Aura. *, P < 0.05. (C) Nitrate concentration in the colon, cecum, and small intestine of mice with and without the AG inhibitor. **, P < 0.01.