The most common organisms causing UTIs are:
- Escherichia coli (E. coli): This bacterium, which is typically found in the gastrointestinal tract, is responsible for the majority of UTIs. It can enter the urinary tract through the urethra and cause infection.
- Staphylococcus saprophyticus: This is the second most common cause of UTIs, particularly in young, sexually active women.
- Klebsiella pneumoniae: This bacterium, found in the gut, is another common cause of UTIs, although less frequent than E. coli.
- Proteus mirabilis: This is known for causing infections in people with abnormal urinary tracts or who have recently had a urinary catheter.
- Enterococcus faecalis: Part of the normal intestinal flora, this bacterium can sometimes cause UTIs, especially in hospitalized patients or those with chronic health conditions.
- Pseudomonas aeruginosa: This bacterium is less common and is usually associated with hospital-acquired infections, often in patients with catheters or those who are immunocompromised.