Should a urine culture showing 10,000 to 49,000 Colony-Forming Units per Liter (CFU/L) of Staphylococcus hominis be treated prior to a urology procedure?

Treatment of Staphylococcus hominis Bacteriuria Before Urologic Procedures

For a urine culture showing 10,000 to 49,000 CFU/L of Staphylococcus hominis, treatment is recommended prior to any urologic procedure that involves mucosal trauma to prevent post-procedural sepsis. 1

Decision Algorithm Based on Procedure Type

Procedures Requiring Treatment

• Procedures with mucosal trauma risk:
  • Transurethral surgery of the prostate (TURP)
  • Transurethral bladder tumor resection (TURBT)
  • Ureteroscopy including lithotripsy
  • Percutaneous stone surgery
  • Any endoscopic procedure breaching the mucosal lining

Procedures Not Requiring Treatment

• Low-risk procedures:
  • Diagnostic cystoscopy
  • Uncomplicated catheter removal/exchange
  • Removal of internal ureteric stents
  • Non-urologic surgeries

Evidence-Based Rationale

The 2019 Infectious Diseases Society of America (IDSA) guidelines provide strong recommendations regarding bacteriuria treatment before urologic procedures:

1. For endoscopic urologic procedures with mucosal trauma, screening for and treating asymptomatic bacteriuria (ASB) is strongly recommended (strong recommendation, moderate-quality evidence) 1

2. The guidelines specifically state that "in individuals with bacteriuria, these are procedures in a heavily contaminated surgical field" and that perioperative antimicrobial treatment confers important benefits 1

3. For non-urologic surgeries, treatment of ASB is not recommended (strong recommendation, low-quality evidence) 1

Treatment Approach

If treatment is indicated based on the procedure type:

1. Obtain targeted therapy: Culture-directed antimicrobial therapy is preferred over empiric treatment (weak recommendation, very low-quality evidence) 1

2. Short-course therapy: A short course (1-2 doses) rather than prolonged therapy is recommended (weak recommendation, low-quality evidence) 1

3. Timing: Antimicrobial therapy should be initiated 30-60 minutes before the procedure 1

Antibiotic Selection Considerations

When selecting an appropriate antibiotic for prophylaxis:

• Consider local resistance patterns
• Choose antibiotics with good tissue penetration
• Options may include:
  • Beta-lactams with beta-lactamase inhibitors
  • Fluoroquinolones (though increasing resistance is a concern)
  • Fosfomycin trometamol (good activity against multidrug-resistant organisms) 2

Important Caveats

1. Staphylococcus hominis considerations:

   • S. hominis is a coagulase-negative staphylococcus that can occasionally cause serious infections 3, 4
   • May demonstrate antibiotic resistance, requiring careful selection of antimicrobial agents 4

2. Procedure-specific risks:

   • Studies have demonstrated that untreated bacteriuria before urologic procedures with mucosal trauma significantly increases risk of postoperative sepsis 1
   • The risk is procedure-dependent, with highest risk in procedures breaching the mucosal lining

3. Colony count interpretation:

   • The 10,000-49,000 CFU/L count represents a relatively low bacterial burden
   • However, the IDSA guidelines do not specify a minimum threshold for treatment before urologic procedures with mucosal trauma

Bottom Line

For urologic procedures involving mucosal trauma, treat the S. hominis bacteriuria with a short course of targeted antibiotics beginning 30-60 minutes before the procedure. For non-invasive diagnostic procedures or non-urologic surgeries, treatment is not necessary.