ABSTRACT
Uropathogenic E. coli (UPEC) is the causative pathogen for most uncomplicated urinary tract infections. Flagellar-mediated motility is essential for virulence and colonization for ascending urinary tract infections. The appendage requirement for surface motility depends on the strain: nonpathogenic E. coli (NPEC) lab strains use pili, NPEC hypermotile derivatives use flagella, and UPEC strains use flagella. E. coli flagella-dependent surface motility had been previously shown to require glucose and amino acids. We examined the nutritional and pathway requirements of the NPEC strain W3110 for pili-dependent surface motility, which have not been previously examined. We then compared these requirements to those for two strains with flagella-dependent surface motility: a variant of W3110, W3110-J1, in which the synthesis of the activator of flagella synthesis has been upregulated and the UPEC strain UTI89. The glucose requirement for W3110 was higher than that for either W3110-J1 or UTI89. The pathways required for motility were also different. W3110, but not UTI89, required the Embden-Meyerhof-Parnas pathway via PfkA; conversely, UTI89, but not W3110, required the Entner-Doudoroff pathway, acetogenesis, and the TCA cycle. Glucose did not control flagella synthesis for W3110-J1 and UTI89. The differing requirements for surface motility are likely to reflect major metabolic differences between strains. The metabolic requirements for UTI89 motility suggest a specific adaptation to the urinary tract environment.
IMPORTANCE Urinary tract infections affect over 50% of women and E. coli is the most common uropathogen. Virulence requires both pili and flagella, and both appendages can contribute to surface motility. Previous studies of E. coli surface motility did not consider the appendage requirement and the ability to switch the surface appendage. The nutrient and pathway requirements for surface motility of a non-pathogenic E. coli strain with either pili- or flagella-dependent surface motility and the uropathogen UTI89 were examined. Pili-dependent surface motility required glycolysis, while flagella-dependent motility required the TCA cycle and oxidative phosphorylation and was less dependent on glycolysis. The distinctive nutrient and pathway requirements for UTI89 motility probably result from metabolic adaptations to the urinary tract.