What is the appropriate treatment for an adult patient with a urinary tract infection (UTI) indicated by 2+ bacteria in urinalysis with microscopy, without any specified allergies or complicating factors?

Management of 2+ Bacteria on Urinalysis with Microscopy

Do Not Treat Asymptomatic Bacteriuria

The presence of 2+ bacteria on urinalysis alone, without symptoms, represents asymptomatic bacteriuria and should NOT be treated with antibiotics in most adult patients. 1

• Pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment 1
• Screening for and treatment of asymptomatic bacteriuria is not recommended for premenopausal nonpregnant women, diabetic women, older persons living in the community, elderly institutionalized subjects, persons with spinal cord injury, or catheterized patients while the catheter remains in situ 1
• The absence of pyuria or a negative dipstick test for leukocyte esterase and nitrite can exclude bacteriuria, but their presence does not confirm symptomatic infection 1

Exceptions Requiring Treatment of Asymptomatic Bacteriuria

Treatment is indicated only in these specific populations:

• Pregnant women: Screen with urine culture at least once in early pregnancy and treat if positive with 3-7 days of antimicrobial therapy 1
• Patients undergoing transurethral resection of the prostate or other urologic procedures where mucosal bleeding is anticipated: Obtain culture before procedure and initiate antimicrobial therapy shortly before the procedure 1

If Symptomatic UTI is Present

Uncomplicated Cystitis (Non-pregnant Women)

First-line treatment options include:

• Nitrofurantoin 100mg twice daily for 5 days 2, 3
• Fosfomycin 3g single dose 2, 3
• Trimethoprim-sulfamethoxazole 160/800mg twice daily for 3 days (only if local resistance <20%) 4, 5

Complicated UTI (Males, Anatomic Abnormalities, Immunosuppression, Healthcare-Associated)

For patients requiring hospitalization or with systemic symptoms, use combination parenteral therapy: 1

• Amoxicillin plus an aminoglycoside, OR
• Second-generation cephalosporin plus an aminoglycoside, OR
• Intravenous third-generation cephalosporin (e.g., ceftriaxone 2g daily) 1, 6

For oral therapy when patient does not require hospitalization:

• Ciprofloxacin 500-750mg twice daily for 7 days (only if local resistance <10% and no fluoroquinolone use in last 6 months) 1, 6
• Trimethoprim-sulfamethoxazole 160/800mg twice daily for 14 days 6, 7

Treatment duration: 7-14 days, with 14 days recommended for men when prostatitis cannot be excluded 1, 6

Catheter-Associated UTI

Only treat if symptomatic (fever, rigors, altered mental status, flank pain, costovertebral angle tenderness, acute hematuria, pelvic discomfort, dysuria, urgency, frequency, or suprapubic pain) 1

• Obtain urine culture before initiating antibiotics 1
• Replace catheter if it has been in place ≥2 weeks before obtaining culture specimen and starting treatment 1
• Treatment duration: 7 days for prompt symptom resolution, 10-14 days for delayed response 1
• Do NOT treat asymptomatic bacteriuria in catheterized patients 1

Critical Diagnostic Steps

Before treating, confirm symptomatic infection:

• Minimum evaluation should include urinalysis for leukocyte esterase and nitrite by dipstick plus microscopic examination for WBCs 1
• If pyuria (≥10 WBCs/high-power field) or positive leukocyte esterase/nitrite is present, then order urine culture with susceptibility testing 1
• Bacteriuria is more specific and sensitive than pyuria for detecting UTI 5
• In moderate or unclear probability cases, always obtain urine culture before treatment 5

Common Pitfalls to Avoid

• Do not treat asymptomatic bacteriuria in non-pregnant, non-surgical patients—this drives antibiotic resistance without clinical benefit 1, 6
• Do not use fluoroquinolones empirically when local resistance exceeds 10% or patient has recent fluoroquinolone exposure 1, 6
• Do not use nitrofurantoin or fosfomycin for complicated UTIs—these have limited tissue penetration and are only appropriate for uncomplicated lower UTIs 6
• Do not fail to obtain culture before treating complicated UTIs, as these have broader microbial spectrum and increased antimicrobial resistance 1