Do we treat a non-pregnant patient with a urine culture positive for Group B Streptococcus (GBS) at 10,000 to 49,000 Colony-Forming Units per Milliliter (CFU/mL)?

Treatment of GBS Bacteriuria in Non-Pregnant Patients

Do not treat asymptomatic GBS bacteriuria at 10,000-49,000 CFU/mL in non-pregnant patients, as this represents asymptomatic bacteriuria that should not receive antibiotics. 1

Key Clinical Decision Point: Symptomatic vs Asymptomatic

The fundamental question is whether your patient has symptoms of urinary tract infection:

If Patient is ASYMPTOMATIC:

• No antibiotic treatment is indicated regardless of colony count, as this represents asymptomatic bacteriuria that should not be treated 1
• The 2019 IDSA guidelines provide strong evidence against screening for or treating asymptomatic bacteriuria in non-pregnant populations 1
• This principle applies even though the colony count (10,000-49,000 CFU/mL) meets traditional bacteriuria thresholds 2

If Patient is SYMPTOMATIC:

Look for these specific UTI symptoms:

• Internal dysuria with frequency, urgency, and voiding of small volumes 1
• Suprapubic pain or abrupt onset of symptoms 1
• Abnormal urinalysis showing leukocyte esterase, pyuria, or hematuria 1

If symptomatic, treat according to standard UTI protocols 1, 2:

• First-line: Penicillin G 500 mg orally every 6-8 hours for 7-10 days 1
• Alternative: Ampicillin 500 mg orally every 8 hours for 7-10 days 1
• Penicillin allergy: Clindamycin 300-450 mg orally every 8 hours (requires susceptibility testing due to ~20% resistance) 1, 2

Critical Distinction from Pregnancy

This management differs fundamentally from pregnant patients, where any GBS in urine at any concentration mandates treatment plus intrapartum prophylaxis due to neonatal disease risk 1, 2. The CDC guidelines for universal treatment of GBS bacteriuria apply specifically to pregnant women and should not be applied to non-pregnant patients 1.

When to Consider Underlying Abnormalities

Screen for urinary tract abnormalities if GBS is present, as 60% of non-pregnant adults with GBS bacteriuria have structural urologic problems 3. This is particularly important in patients with:

• Recurrent UTIs 1
• Chronic renal failure 3
• History of urologic procedures 3

Risks of Unnecessary Treatment

Treating asymptomatic bacteriuria causes:

• Unnecessary antibiotic exposure and resistance development 1
• Potential adverse drug effects without clinical benefit 1
• False reassurance that symptoms have been addressed when the true cause remains unidentified 1

Common Pitfall to Avoid

Do not reflexively treat based solely on the laboratory report showing GBS at 10,000-49,000 CFU/mL. The presence of bacteria in urine does not equal infection requiring treatment in non-pregnant patients 1. Always correlate with clinical symptoms and urinalysis findings before initiating antibiotics.