Bacteriuria describes the presence of bacteria in urine. It may reflect contamination from the urethra or signify infection of the urinary tract.
Explanation
Urine from the kidneys and bladder is normally sterile. Bacteria can enter the urinary tract through the urethra and multiply in the bladder or kidneys. Clinicians detect bacteriuria by microscopic examination, dipstick testing and quantitative urine culture; counts greater than 10⁵ colony‑forming units per millilitre often indicate significant bacteriuria, though lower counts may be meaningful in symptomatic patients. The most common organisms are Gram‑negative enteric bacteria, especially Escherichia coli, which ascend from the perineum. Bacteriuria may be symptomatic, presenting with dysuria, urgency, frequency and flank pain, or asymptomatic, in which case the patient has no urinary symptoms.
Clinical Significance
Asymptomatic bacteriuria is common in elderly individuals and people with indwelling catheters and usually does not require treatment. Exceptions include pregnant women, recent renal transplant recipients, children with vesicoureteral reflux and patients undergoing urological procedures; in these groups, bacteriuria can lead to complications such as pyelonephritis or premature birth. Symptomatic bacteriuria indicates a urinary tract infection and is treated with targeted antibiotics after culture and sensitivity testing. Proper sampling technique and prompt processing of urine specimens are critical to avoid contamination and false‑positive results.
Identifying and managing bacteriuria helps prevent progression to upper urinary tract infection and sepsis and avoids unnecessary antibiotics when no treatment is needed.
Related Terms: Urinary Tract Infection, Escherichia coli, Pyuria, Urinalysis, Asymptomatic Bacteriuria