What does it mean on a Urinalysis (UA) when it says sensitive to 2 out of 38 antibiotics?

Understanding "Sensitive ≤2/38" on a Urinalysis Report

When a urinalysis report indicates "sensitive ≤2/38," it means that the bacterial organism isolated from the urine sample is sensitive to 2 or fewer antibiotics out of 38 antibiotics tested, indicating a highly resistant organism that has limited treatment options.

Interpreting Antibiotic Sensitivity Results

• Antibiotic sensitivity testing is performed on bacteria isolated from urine cultures to determine which antibiotics will be effective against the infection 1, 2
• The notation "≤2/38" specifically indicates that the organism is sensitive to only 2 or fewer antibiotics out of a panel of 38 antibiotics tested 3
• This result suggests a multidrug-resistant organism, which is concerning as it significantly limits treatment options 3, 4

Clinical Significance

• A highly resistant organism (sensitive to ≤2/38 antibiotics) requires careful antibiotic selection based on the limited sensitivity profile 3
• This finding is particularly concerning as it may indicate:
  • Previous antibiotic exposure leading to resistance development 5
  • Possible healthcare-associated infection rather than community-acquired 3
  • Need for consultation with infectious disease specialists for optimal management 3

Management Implications

• Treatment should be guided by the specific antibiotics to which the organism remains sensitive 1, 2
• For highly resistant organisms, options may include:
  • Newer antibiotics or antibiotic combinations 3
  • Higher doses or extended duration of therapy 3
  • Parenteral (intravenous) rather than oral therapy 6

Common Pitfalls in Interpretation

• Do not confuse sensitivity results with the number of bacteria present - this notation refers specifically to antibiotic sensitivity, not bacterial count 7
• Do not assume all urinary bacteria require treatment - asymptomatic bacteriuria is common, particularly in older adults, and should not be treated with antibiotics despite resistance patterns 8
• Do not overlook the clinical context - treatment decisions should incorporate patient symptoms, not just laboratory findings 8

Follow-up Recommendations

• For highly resistant organisms (sensitive to ≤2/38 antibiotics), consider:
  • Repeat culture after treatment to confirm eradication 9
  • Investigation for anatomical abnormalities or foreign bodies (like stones or catheters) that may harbor resistant bacteria 9
  • Evaluation for recurrent or complicated UTI risk factors 5

Antimicrobial Stewardship Considerations

• Highly resistant organisms often emerge from inappropriate antibiotic use 5
• When treating infections with limited antibiotic options:
  • Use the narrowest spectrum agent to which the organism is sensitive 3
  • Optimize dosing and duration to prevent further resistance development 3
  • Consider infectious disease consultation for complex resistance patterns 3, 4