Characterization of the Entner-Douderoff Pathway inPseudomonas aeruginosaCatheter-associated Urinary Tract Infections

Abstract

AbstractPseudomonas aeruginosais an opportunistic nosocomial pathogen responsible for catheter-associated urinary tract infections (CAUTI). In a murine model ofP. aeruginosaCAUTI, we previously demonstrated that urea within urine suppresses quorum sensing and induces the Entner-Douderoff (E-D) pathway. The E-D pathway consists of the geneszwf, pgl, edd, andeda. Zwf and Pgl convert glucose-6-phosphate into 6-phosphogluconate. Edd hydrolyzes 6-phosphogluconate to 2-keto-3-deoxy-6-phosphogluconate (KDPG). Finally, Eda cleaves KDPG to glyceraldehyde-3-phosphate and pyruvate, which enters the citric acid cycle. Here, we generated in-frame E-D mutants in strain PA14 and assessed their growth phenotypes on chemically defined media. These E-D mutants have a growth defect when grown on glucose or gluconate as sole carbon source which are similar to results previously reported for PAO1 mutants lacking E-D genes. RNA-sequencing following short exposure to urine revealed minimal gene regulation differences compared to the wild type. In a murine CAUTI model, virulence testing of E-D mutants revealed that two mutants lackingzwfandpglshowed minor fitness defects. Infection with the Δpglstrain exhibited a 20% increase in host survival, and the Δzwfstrain displayed decreased colonization of the catheter and kidneys. Consequently, our findings suggest that the E-D pathway inP. aeruginosais dispensable in this model of CAUTI.ImportancePrior studies have shown that the Entner-Douderoff pathway is up-regulated whenPseudomonas aeruginosais grown in urine. Pseudomonads use the Entner-Douderoff pathway to metabolize glucose instead of glycolysis which led us to ask whether this pathway is required for urinary tract infection. Here, single-deletion mutants of each gene in the pathway were tested for growth on chemically defined media with single-carbon sources as well as complex media. The effect of each mutant on global gene expression in laboratory media and urine was characterized. The virulence of these mutants in a murine model of catheter-associated urinary tract infection revealed that these mutants had similar levels of colonization indicating that glucose is not the primary carbon source utilized in the urinary tract.