What is the best course of treatment for a 37-year-old male with a recurrent urinary tract infection (UTI) due to Group B streptococcus (GBS), previously treated with amoxicillin (amoxicillin), now presenting with urinary frequency and painful urination?

Management of Recurrent Group B Streptococcus UTI in Adult Male

For a 37-year-old male with recurrent Group B streptococcus UTI symptoms after initial treatment with amoxicillin, a 7-day course of trimethoprim-sulfamethoxazole is recommended as the most effective treatment option.

Diagnosis Confirmation

Before initiating treatment, it's essential to confirm the recurrence:

• Obtain a urine culture to confirm the diagnosis and determine antimicrobial susceptibility 1
• Assess for potential complicating factors, as UTIs in males are generally considered complicated 1, 2
• Evaluate for underlying structural or functional abnormalities that may contribute to recurrence

Treatment Approach

First-line Treatment

1. Antimicrobial therapy:

   • Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 7 days) is the recommended treatment for UTIs in men 1
   • This is preferred over amoxicillin for recurrent infection, as the initial treatment failure suggests possible resistance

2. Treatment duration:

   • 7-day course is recommended for males with UTI 1
   • Extended treatment (up to 14 days) may be considered if prostatitis cannot be excluded 1

Alternative Options

If trimethoprim-sulfamethoxazole is contraindicated or if susceptibility testing indicates resistance:

• Fluoroquinolones can be prescribed based on local susceptibility patterns 1
• Nitrofurantoin is not recommended for males due to poor prostatic penetration
• Cephalosporins may be considered if susceptibility testing supports their use 1

Evaluation for Underlying Causes

Unlike in women under 40, males with UTI warrant further evaluation:

• Consider urological evaluation to identify structural abnormalities 2
• Assess for potential risk factors including:
  • Urinary obstruction
  • Incomplete bladder emptying
  • Diabetes mellitus
  • Immunosuppression
  • Recent instrumentation 2

Prevention Strategies

After treating the acute episode, implement preventive measures:

• Increased fluid intake to reduce risk of recurrence 2
• Consider methenamine hippurate (1g twice daily) for non-antibiotic prophylaxis 2
• For recurrent infections despite these measures, consider:
  • Low-dose continuous antimicrobial prophylaxis for 6-12 months
  • Post-coital antimicrobial prophylaxis if infections are related to sexual activity 2

Clinical Pearls and Pitfalls

• Male UTIs are complicated: All UTIs in males are considered complicated and require more thorough evaluation than in females 1, 2
• Group B streptococcus considerations: While E. coli is the most common UTI pathogen, Group B streptococcus can cause persistent infections and may require different treatment approaches 3, 4
• Avoid treatment failure: Do not repeat the same antibiotic (amoxicillin) that failed initially 1
• Duration matters: Shorter courses (<7 days) may lead to treatment failure in males 1
• Follow-up: Ensure symptoms resolve completely; persistent symptoms warrant further investigation for potential abscess formation or prostatitis 3

By following this structured approach, recurrent Group B streptococcus UTI can be effectively managed while minimizing the risk of further recurrences and complications.