Bacterial Microcompartment-Mediated Ethanolamine Metabolism in Escherichia coli Urinary Tract Infection

Urinary tract infections (UTIs) are common and in general are caused by intestinal uropathogenic (UPEC) ascending via the urethra. Microcompartment-mediated catabolism of ethanolamine, a host cell breakdown product, fuels the competitive overgrowth of intestinal , both pathogenic enterohemorrhagic and commensal strains. During a UTI, urease-negative bacteria thrive, despite the comparative nutrient limitation in urine. The role of ethanolamine as a potential nutrient source during UTIs is understudied. We evaluated the role of the metabolism of ethanolamine as a potential nitrogen and carbon source for UPEC in the urinary tract. We analyzed infected urine samples by culture, high-performance liquid chromatography, reverse transcription-quantitative PCR, and genomic sequencing. The ethanolamine concentration in urine was comparable to the concentration of the most abundant reported urinary amino acid, d-serine. Transcription of the operon was detected in the majority of urine samples containing screened. All sequenced UPEC strains had conserved operons, while metabolic genotypes previously associated with UTI ( , ) were mainly limited to phylogroup B2. ethanolamine was found to be utilized as a sole source of nitrogen by UPEC strains. The metabolism of ethanolamine in artificial urine medium (AUM) induced metabolosome formation and provided a growth advantage at the physiological levels found in urine. Interestingly, (which encodes acetaldehyde dehydrogenase) was required for UPEC strains to utilize ethanolamine to gain a growth advantage in AUM, suggesting that ethanolamine is also utilized as a carbon source. These data suggest that urinary ethanolamine is a significant additional carbon and nitrogen source for infecting strains.