Urine Culture

1. Collection
   1. Sterile Methods
      1. Catheterized Urine
      2. Suprapubic Tap
   2. Clean Methods
      1. Clean Catch Urine Collection
      2. Bag Urine Collection
2. Specimen handling
   1. Volume: 5 ml (0.2 ml minimum)
   2. First morning void is ideal specimen
   3. Deliver to lab or refrigerate within 30 minutes
3. Interpretation: Clean Voided Specimen
   1. Normal: <10,000 organisms per ml
   2. Urinary Tract Infection
      1. Boys
         1. Organisms >10,000 per ml suggests UTI likely
      2. Girls
         1. Organisms >100,000 per ml suggests UTI
            1. Three specimens: 95% probability of UTI
            2. Two specimens: 90% probability of UTI
            3. One specimen: 80% probability of UTI
         2. Organisms >10,000 per ml needs repeat Urine Culture
4. Interpretation: Transurethral Catheterization
   1. Normal: <1,000 organisms per ml
   2. Urinary Tract Infection
      1. Organisms >10,000 per ml suggests UTI
      2. Organisms >1,000 per ml needs repeat Urine Culture
5. Interpretation: Suprapubic aspiration in infants
   1. Gram Negative Bacilli: any number suggests UTI (99%)
   2. Gram Positive Cocci: >1-2,000 suggests UTI (99%)
6. References
   1. Hellerstein (1982) Pediatr Infect Dis 1:271-81 [PubMed]