What is the recommended treatment for a male patient with a beta-hemolytic Group B Streptococcus (GBS) urinary tract infection (UTI)?

Treatment of Beta-Hemolytic Group B Streptococcus (GBS) UTI in Men

Men with beta-hemolytic GBS urinary tract infections should be treated with amoxicillin or ampicillin for 14 days, as male UTIs are classified as complicated infections requiring extended therapy to prevent prostatic involvement. 1, 2, 3

Antibiotic Selection

First-Line Treatment

• Amoxicillin is the preferred oral agent for GBS UTI, as the FDA label specifically indicates amoxicillin for genitourinary tract infections caused by β-lactamase-negative Enterococcus faecalis and other susceptible organisms, which includes beta-hemolytic streptococci 2
• The recommended dosage is 500 mg every 8 hours or 875 mg every 12 hours for 14 days 2
• Ampicillin has demonstrated successful treatment outcomes in historical studies of GBS urinary infections in males 3

Alternative Options for Severe Cases or Hospitalized Patients

• Intravenous third-generation cephalosporins (such as ceftriaxone 1-2 g once daily) can be used for empiric coverage when GBS is suspected but not yet confirmed 1, 4
• Amoxicillin plus an aminoglycoside or second-generation cephalosporin plus aminoglycoside are acceptable combination regimens for complicated UTI when broader coverage is initially needed 1, 4

Treatment Duration

• 14 days is mandatory for all male UTIs because prostatitis cannot be reliably excluded, and shorter courses have proven inferior 1, 4
• A 2017 randomized trial demonstrated that 7-day ciprofloxacin achieved only 86% cure rate versus 98% with 14-day treatment in men, establishing the evidence base for extended therapy 1
• Treatment should continue for a minimum of 48-72 hours beyond symptom resolution 2

Critical Diagnostic Steps

• Obtain urine culture and susceptibility testing before initiating therapy to confirm GBS and rule out polymicrobial infection 1, 4
• Consider urethral specimens in men, as GBS can colonize the urethra and may represent the source of infection 3
• Evaluate for underlying urological abnormalities (obstruction, incomplete voiding, stones) that require management beyond antibiotics alone 1, 4

Important Cautions and Pitfalls

Avoid These Common Errors:

• Do not use fluoroquinolones (ciprofloxacin, levofloxacin) as first-line therapy for GBS UTI, as beta-lactams provide superior coverage for streptococcal infections 1, 5
• Do not use nitrofurantoin or fosfomycin if the patient has systemic symptoms, as these agents achieve inadequate blood levels and cannot treat potential prostatic involvement 4
• Do not treat for only 7 days, even if the patient feels better, as this leads to treatment failure rates exceeding 14% in men 1

Resistance Considerations:

• GBS exhibits high rates of resistance to macrolides (erythromycin 36.3%, azithromycin 44.5%), clindamycin (26%), and tetracyclines (81.5%), making these agents inappropriate choices 6
• Beta-lactams remain universally effective against GBS, with no reported resistance to penicillins or cephalosporins 5, 6

Follow-Up Management

• Monitor for symptom resolution within 48-72 hours of initiating appropriate therapy 2
• Consider follow-up urine culture in complicated cases to document bacterial eradication 4
• Address any identified urological abnormalities (prostatic hypertrophy, urethral stricture, bladder dysfunction) to prevent recurrence, as antimicrobial therapy alone is insufficient without source control 1, 4
• In males with recurrent GBS UTI, evaluate for chronic prostatitis requiring longer treatment courses 1