Fig 5. Co-treatment of vitamin A and antibiotics decreases systemic Salmonella burden and improves survival in VAD male mice.

VAD and control Slc11a1^+/+ mice were generated and infected with multidrug resistant S. Typhimurium D23580 at 9 weeks of age. Mock-treated mice received 100 μl of sterile PBS administered by oral gavage on day 1 and day 2 post-infection. Vitamin A-treated mice received 600 IU of retinyl palmitate in 100 μl of sterile PBS administered by oral gavage on day 1 and day 2 post-infection and changed to control diet at day 1 post-infection. The antibiotic enrofloxacin (abx) was administered at day 2 post-infection in the drinking water at 0.05 mg/ml (A). Systemic burden of S. Typhimurium was characterized for VAD male (B) and VAD female (C) mice (n = 4–6) as CFU in liver, spleen and blood at necropsy 4 days post-infection. Data are reported as mean ± SEM. Significance was determined on log-transformed values with a Kruskal-Wallis test and Dunn’s multiple comparisons test (*, p<0.05; ns, not significant). (D) Percent survival for control and treated VAD male mice was assessed with an 8-day Kaplan-Meier survival curve (n = 6–16). An enrofloxacin concentration of 0.01 mg/ml was used in drinking water treatment, and oral gavage treatments were given as previously described. Significance was determined with pairwise comparisons between the control group and each other treatment group using a log-rank (Mantel-Cox) test (*, p<0.05; ns, not significant). Data from untreated controls are also included in Fig 1.