Which bacteria are most commonly associated with urinary tract infections (UTIs)?

Escherichia coli is the most commonly associated bacterium with urinary tract infections (UTIs) due to its prevalence in the gastrointestinal tract, particularly in the intestines. The bacteria can easily enter the urinary tract, often through the urethra, and cause an infection. Its virulence factors, such as fimbriae, enable it to adhere to the uroepithelial cells and establish an infection, which is a significant aspect of its pathogenicity.

In addition to E. coli, other bacteria like Proteus mirabilis and Klebsiella pneumoniae can also cause UTIs, but they are less prevalent than E. coli. Staphylococcus aureus, while capable of causing various infections, is not typically associated with UTIs. This contextual understanding highlights why E. coli is the predominant pathogen in UTI cases.