Should a 92-year-old lady with a urine culture showing Enterococcus faecalis (E. faecalis) and significant leukocyturia (large amount of leukocytes) be treated with antibiotics?

Treatment of Symptomatic Urinary Tract Infection with Enterococcus faecalis

Yes, this 92-year-old lady with symptomatic Enterococcus faecalis urinary tract infection (49,000 colony counts) and significant leukocyturia should be treated with antibiotics.

Rationale for Treatment

The presence of symptoms along with significant bacteriuria (49,000 colony counts) and leukocyturia indicates a true urinary tract infection rather than asymptomatic bacteriuria. In elderly patients, untreated UTIs can lead to significant morbidity including:

• Progression to pyelonephritis
• Bacteremia
• Sepsis
• Increased mortality risk, especially in the elderly

Antibiotic Selection Algorithm

First-line options:

1. Nitrofurantoin (100mg twice daily for 5 days)

   • Highly effective against E. faecalis
   • Low resistance rates
   • Recommended by guidelines 1
   • Caution: Avoid if CrCl <30 mL/min

2. Fosfomycin (3g single dose)

   • Convenient single-dose regimen
   • Effective against E. faecalis
   • Good option for elderly patients 1

3. Ampicillin or Amoxicillin (500mg three times daily for 5-7 days)

   • E. faecalis generally remains susceptible 1, 2
   • Consider if susceptibility confirmed

Alternative options (if first-line contraindicated):

1. Amoxicillin-clavulanate (875/125mg twice daily for 5-7 days)

   • 100% susceptibility reported in studies 3
   • Broader spectrum than needed but effective

2. Ciprofloxacin (if susceptible)

   • Only if susceptibility confirmed (89.4% susceptibility reported) 3
   • Reserve due to resistance concerns and risk of C. difficile in elderly

For severe infection/complicated UTI:

1. Parenteral ampicillin (with or without gentamicin)
2. Vancomycin (if penicillin-allergic)
3. Daptomycin (for resistant strains) 4

Important Clinical Considerations

Factors to assess:

• Severity of symptoms - fever, flank pain may indicate upper UTI
• Renal function - impacts drug selection and dosing
• Medication allergies - especially to beta-lactams
• Prior antibiotic exposure - may influence resistance patterns
• Presence of urinary catheter - consider removal if present

Monitoring recommendations:

• Clinical response within 48-72 hours
• Monitor renal function if using nephrotoxic agents
• Consider repeat culture only if symptoms persist

Antibiotic Resistance Considerations

• E. faecalis shows high resistance to tetracycline (53.2%), erythromycin (80.8%), clindamycin (100%), and metronidazole (100%) 3
• Low resistance to nitrofurantoin, vancomycin, linezolid and teicoplanin 2
• Avoid empiric fluoroquinolones unless susceptibility confirmed due to increasing resistance

Pitfalls to Avoid

1. Do not treat asymptomatic bacteriuria in the elderly (but this patient is symptomatic)
2. Do not use tetracyclines, erythromycin, clindamycin, or metronidazole as they have poor activity against E. faecalis 3
3. Avoid unnecessary broad-spectrum antibiotics which may promote resistance
4. Do not delay treatment in symptomatic elderly patients as they are at higher risk for complications
5. Do not forget to reassess within 48-72 hours to ensure clinical improvement

In this 92-year-old patient with symptomatic E. faecalis UTI, prompt antibiotic therapy is warranted, with nitrofurantoin or fosfomycin as preferred first-line options if renal function permits.