Common Bacteria Causing UTI (Urinary Tract Infection)


A urinary tract infection (UTI) is an infection that affects any part of the urinary system, which includes the kidneys, ureters, bladder and urethra. The urinary system is responsible for producing, storing and eliminating urine from the body. Urine is a liquid waste that contains water, salts and other substances filtered from the blood by the kidneys.

UTIs are very common, especially among women and people assigned female at birth (AFAB), who have a shorter urethra than men and people assigned male at birth (AMAB). This makes it easier for bacteria to enter the urinary tract and cause an infection. UTIs can also affect children, but they are less common.

The most common cause of UTIs is bacteria from the gastrointestinal (GI) tract, such as Escherichia coli (E. coli), that enter the urinary tract through the urethra. The urethra is the tube that carries urine from the bladder to the outside of the body. The bacteria can then multiply and spread to the bladder, causing cystitis (bladder infection), or to the kidneys, causing pyelonephritis (kidney infection).

Other factors that can increase the risk of UTIs include:

  • Sexual activity, which can introduce bacteria into the urinary tract.
  • Pregnancy, which can put pressure on the bladder and ureters and make it harder to empty the bladder completely.
  • Menopause, which can reduce estrogen levels and affect the balance of bacteria in the vagina and urethra.
  • Certain birth control methods, such as diaphragms or spermicides, which can irritate the urethra or change the vaginal flora.
  • Kidney stones or other urinary tract abnormalities, which can block or slow down urine flow and create a breeding ground for bacteria.
  • Medical conditions such as diabetes, multiple sclerosis, stroke or spinal cord injury, which can affect bladder function or nerve signals to the urinary tract.
  • Weakened immune system, which can make it harder to fight off infections.
  • Use of catheters or other medical devices in the urinary tract, which can introduce bacteria or cause irritation or injury.

UTIs can cause various symptoms depending on which part of the urinary tract is affected. Some common symptoms include:

  • A strong urge to urinate that doesn`t go away
  • A burning feeling when urinating
  • Urinating often and passing small amounts of urine
  • Urine that looks cloudy, bloody or foul-smelling
  • Pelvic pain or pressure
  • Lower back pain or flank pain
  • Fever, chills, nausea or vomiting

UTIs are usually diagnosed by testing a urine sample for bacteria and other signs of infection. Sometimes, other tests such as urine culture, cystoscopy (examining the inside of the bladder with a camera), CT scan or MRI may be needed to identify the type of bacteria causing the infection or to check for any abnormalities in the urinary tract.

UTIs are usually treated with antibiotics that kill the bacteria causing the infection. The type, dose and duration of antibiotics depend on the severity of the infection and the type of bacteria involved. It is important to complete the prescribed course of antibiotics even if symptoms improve to prevent recurrence or complications.

Some self-care measures that can help prevent or relieve UTI symptoms include:

  • Drinking plenty of water to flush out bacteria from the urinary tract
  • Wiping from front to back after using the toilet to avoid spreading bacteria from the anus to the urethra
  • Avoiding feminine hygiene products such as sprays or douches that can irritate the urethra or alter the vaginal flora
  • Cleaning the genital area before and after sexual intercourse and urinating after sex to remove any bacteria that may have entered the urinary tract
  • Using heating pads or warm compresses to ease pain in the pelvic or lower back area

UTIs are usually not serious if treated promptly and properly. However, if left untreated or if they recur frequently, they can lead to complications such as:

  • Recurrent infections that may damage the kidneys or bladder
  • Permanent kidney damage that may impair kidney function or cause kidney failure
  • Narrowing of the urethra (urethral stricture), especially in men and AMAB people, that may obstruct urine flow and increase infection risk
  • Sepsis, a life-threatening condition that occurs when an infection spreads to the bloodstream and causes inflammation throughout the body

If you have any symptoms of a UTI or if you have any questions or concerns about your urinary health, you should consult your healthcare provider as soon as possible. UTIs are common and treatable, but they can also be prevented with proper hygiene and care.