1 μg/ml). Results were reproduced in 3 biological replicates. Bioinformatics Microarray data were analyzed using gene annotations provided by the SEED database http://​www.​theSEED.​org/​ and Pseudomonas Genome Database http://​www.​pseudomonas.​com/​. Statistical analysis Statistical analysis of the data was performed with Student

t-test using Sigma plot software, and Kaplan-Maier survival graphs using SPSS 18 software. Results Surgical injury (30% hepatectomy) increases the distal intestinal mucosal pH that can be maintained by pH adjusted oral phosphate supplementation In order to determine whether the pH of the intestinal selleck mucosa, the major colonization site of microbial pathogens, is affected by surgical injury, mucosal pH was measured using phenol red staining of intestinal segments of control and surgically SGC-CBP30 cell line injured mice. The pH of proximal colon segments, the densest region of microbial https://www.selleckchem.com/products/torin-1.html adherence, was measured in mice 22 hours following sham laparotomy or 30% hepatectomy. Results demonstrated pH shift from ~6.0 in sham mice to ~ 7.0-7.5 in mice subjected to 30% hepatectomy (Figure 1A). In mice drinking an oral ad libitum solution of 25 mM phosphate buffer adjusted to pH 6.0 or 7.5, intestinal mucosal pH in the proximal colon stabilized to the corresponding pH suggesting that, in mice, distal intestinal pH can be manipulated by oral pH adjustment (Figure 1B). Figure 1 Intestinal

mucus pH. Red phenol staining of (A) proximal colon of control and surgically stressed mice (30% hepatectomy), and (B) proximal colon of surgically stressed mice drinking 25 mM phosphate solution at pH 7.5 or pH 6.0. Experiments were performed in triplicate and representative images of the colon isolated and stained with 0.04% phenol red from 2 mice of each group are shown. Oral phosphate protects against the lethal effect of intestinal P. aeruginosa following surgical injury in a pH dependent manner We next determined the effect of pH on the expression of a lethal phenotype in intestinal P. aeruginosa using a model developed by our laboratory [16, Thiamet G 18]. In this model, mice are subjected

to an otherwise fully recoverable surgical injury (30% hepatectomy) with simultaneous injection of P. aeruginosa into the cecum which consistently results in > 60% mortality in 48 hr. In the present study, to generate negative controls, groups of mice were subjected to hepatectomy without injection of P. aeruginosa and drank either water, or 25 mM [Pi], pH 6.0, or 25 mM [Pi], pH 7.5 ad libitum (n = 16/group). No mice in any of these groups developed signs of sepsis or mortality at 48 hours and appeared completely healthy. In contrast, and consistent with our previous studies in this model [7–9], mice drinking water ad libitum and intestinally inoculated with P. aeruginosa PAO1 following surgical hepatectomy developed gross signs of sepsis (chromodacctyrrhea, ruffled fur, lethary, scant diarrhea) and a ~60% mortality rate at 48 hours.