Urine culture-> organism + susceptibility (S), resistance (R)

Urinalysis (UA) – what the numbers mean

• WBCs (pyuria):

  • Normal: 0–5 /HPF

  • >10 /HPF → infection likely

• RBCs:

  • Normal: 0–3 /HPF

  • ↑ → stones, infection, trauma

• Leukocyte esterase (LE):

  • Reported as negative / trace / small / moderate / large

  • Moderate–large = significant WBCs

• Nitrites:

  • Positive = gram-negative bacteria (e.g., E. coli)

  • Negative doesn’t rule out infection

• Bacteria:

  • Few / moderate / many

  • Moderate–many = infection more likely

Urine culture – colony count (CFU)

• ≥100,000 CFU/mL (10⁵) → definite infection

• 10,000–100,000 (10⁴–10⁵) → possible (use clinical context)

• <10,000 → usually contamination