Urine Culture, Routine

Additional Information:


UFHPL Epic order code: LAB239

A single culture is about 80 percent accurate for females; two containing the same organism with a count of 105 or more represent a 95 percent chance of true bacteriuria; three such specimens mean virtual certainty of true bacteriuria.

Urinary tract infection is significantly higher in women who use diaphragm-spermicide contraception, perhaps secondary to increased vaginal pH and a higher frequency of vaginal colonization with E coli.1
A single clean voided specimen from an adult male may be considered diagnostic with proper preparation and care in specimen collection. If the patient is receiving antimicrobial therapy at the time the specimen is collected, any level of bacteriuria may be significant. When more than two organisms are recovered, the likelihood of contamination is high; thus, the significance of definitive identification of the organisms and susceptibility testing in this situation is severely limited. A repeat culture with proper specimen collection including patient preparation is often indicated. Periodic evaluation of diabetics and pregnant women for asymptomatic bacteriuria has been recommended.2 Institutionalized patients, especially elderly individuals, are prone to urinary tract infections, which can be severe.3 Cultures of specimens from Foley catheters yielding multiple organisms with high colony counts usually represents colonization of the catheter and not true significant bacteriuria. Most laboratories limit the number of organisms that will be identified when recovered from urine to two. Similarly, most do not routinely perform susceptibility tests on isolates from presumably contaminated specimens. Failure to recover aerobic organisms from patients with pyuria or positive Gram stains of urinary sediment may indicate the presence of mycobacteria or anaerobes.

Footnotes

  1. Stamm WE, Hooton TM, Johnson JR, et al. Urinary tract infections: From pathogenesis to treatment. J Infect Dis. 1989 Mar; 159(3):400-406 (review). PubMed 2644378
  2. Andriole VT. Urinary tract infections in the 90s: Pathogenesis and management. Infection. 1992; 20(Suppl 4):S251-S256. PubMed 1294512
  3. Nicolle LE. Urinary tract infection in the elderly: How to treat and when? Infection. 1992; 20(Suppl 4):S261-S265. PubMed 1294514

References

  • Cavagnolo R. Evaluation of incubation times for urine cultures. J Clin Microbiol. 1995 Jul; 33(7):1954-1956. PubMed 7665682
  • Clarridge JE, Pezzlo MT, Vosti KL. Laboratory Diagnosis of Urinary Tract Infections. In: Weissfeld AS, ed. Cumitech 2. Washington, DC: ASM Press; March 1987.
  • Joho KL, Soliman H, Weinstein MP. Comparison of one-day versus two-day incubation of urine cultures. Diagn Microbiol Infect Dis. 1995 Jan; 21(1):55-56. PubMed 7789098
  • Ronald AR, Nicolle LE, Harding GKM. Standards of therapy for urinary tract infections in adults. Infection. 1992; 20(Suppl 3):S164-S170. PubMed 1490743
  • Stamm WE. Criteria for the diagnosis of urinary tract infection and for the assessment of therapeutic effectiveness. Infection. 1992; 20(Suppl 3):S151-S159. PubMed 1490740

CPT Code(s):

87086

Specimen Requirements:

Important: Specimens from other sources, such as genital, stool, urine, upper and lower respiratory specimens, cannot be cultured under the aerobic bacterial culture test number. If specimens are incorrectly submitted with an order for aerobic bacterial culture, the laboratory will process the specimen for the test based on the source listed on the request form. The client will not be telephoned to approve this change, but it will be indicated on the report.
Type: Urine
Container/Tube: Vacutainer® gray-top urine culture transport tube with preservative

Sample Volume: Collect specimens to the fill line on the Vacutainer® gray-top urine culture transport tube

Storage: Store specimens at room temperature.
Rejection Criteria:

  • Unrefrigerated specimen older than two hours may be subject to overgrowth and may not yield valid results.
  • Unlabeled specimen or name discrepancy between specimen and request label
  • Specimen in expired transport container
    Specimen received after prolonged delay (usually more than 36 hours for urine)
  • Specimen collected via Foley catheter
  • Unpreserved specimen

Use:

This test includes:

  • Culture
  • Quantitation, isolation, identification (additional charges/CPT codes may apply) and susceptibility testing of up to two organisms at > 10,000 colonies/mL if culture results warrant (additional charges/CPT codes may apply).
CPT coding for microbiology and virology procedures often cannot be determined before the culture is performed.

Methodology:


Culture