URINE CULTURE

LAB239

Includes isolation of potentially pathogenic aerobic organisms and susceptibility testing as indicated. Specimen source is required on request form for processing. The only acceptable urine specimen for anaerobic culture is a suprapubic aspiration.

Patient collects a clean catch mid-stream specimen in a sterile container. First morning specimen is preferred

Sterile container
Sterile cup
Pediatric bagged urine

Refrigerate if specimen cannot be tested immediately. Specimen good for 24 hrs after collection if refrigerated

Set Up:Daily Report Available:2 days

No growth

Urine cultures are obtained to detect the presence of bacteria. However, a patient with bacteruria does not necessarily have a urinary tract infection. To make this determination, a physician needs more information, such as how the urine was collected, the clinical presentation, the age and sex of the patient, whether instrumentation or catheterization of the urinary tract has been performed, and/or the state of hydration of the patient. Patients who are older, female patients, and patients who are and have been catheterized are at increased risk to develop urinary tract infection. There are other predisposing factors, but these appear to be the most important. Most urinary tract infections are retrograde; that is, bacteria from the lower urethra ascend by some method into the bladder. Hematogenesis infection, which is secondary to bacteremia caused by infection at a site distal to the urinary tract, is a rare mechanism of acquiring a urinary tract infection. When hematogenous spread occurs, the bacteremic pathogens usually localize at the site of a structural abnormality such as a stone, stricture, tumor, etc. Diagnostic symptoms of UTI can include burning urination, nocturia, frequency, incontinence, dysuria, and/or gross hematuria. Non-diagnostic symptoms can include fever of unknown origin, hypothermia, abdominal, back or flank pain, malaise, dehydration, and/or hypotension. Asymptomatic infections also occur. E. coli is the dominant etiologic agent, causing 80% of the uncomplicated urinary tract infections. Proteus, Klebsiella, Enterobacter, Pseudomonas, Enterococcus and other intestinal bacterial pathogens represent a second order of importance and are more likely to be encountered if there is a predisposing factor. Staph saprophyticus, and Lactobacilli are much less common as UTI pathogens, but they do cause small numbers of clinically significant infections. Urinary tract infections caused by acid fast bacilli or anaerobic bacterial are rare and usually secondary to an extreme predisposing factor. The urinary tract above the urethra is sterile in healthy humans, but the urethra is normally colonized with many different bacteria and so urine specimens collected by a non-invasive method become contaminated during passage. Commensal bacteria are differentiated from potential pathogens by quantitative cultures of urine. Patients with pyuria who are sexually active but have negative urine cultures may be infected with chlamydia or Neisseria gonorrhoeae. Multiple organisms in a urine specimen usually suggest a poorly collected specimen. However, polymicrobic infections are possible in patients with urinary tract structural abnormalities.