The urinary system is a system of organs whose task is to create and eliminate urine, and urinary tract infections can affect any part of the urinary system, however, most affect the bladder and urethra, or the lower urinary tract. With the onset of a urinary tract infection, the body responds with an inflammatory response and symptoms that correspond to the site of infection. Urinary tract infections are the second most common type of infection in the outpatient setting, immediately after respiratory infections, while in the hospital they represent the most common type of nosocomial infections. The uropathogen Escherichia coli causes between 70% to 95% of nosocomial urinary tract infections, while it is responsible for 50% of nosocomial urinary tract infections. Most urinary tract infections do not require hospitalization but are treated at the primary care level, so the fact that most nosocomial urinary tract infections are associated with bladder catheterization is not surprising. The trend of increasing antibiotic resistance of Escherichia coli can be attributed to the fact that most nosocomial urinary tract infections are caused by multiple resistant strains, and urinary tract infections are known to be treated empirically.