Management of Asymptomatic MRSA Bacteriuria

Understanding Asymptomatic Bacteriuria

• The European Association of Urology (EAU) defines asymptomatic bacteriuria (ABU) as bacterial colonization of the urinary tract without causing symptoms, and recommends against treatment in most cases 1
• ABU is defined as a mid-stream urine sample showing bacterial growth >10^5 CFU/mL in two consecutive samples for women or in a single sample for men, according to the EAU guidelines 1
• The spectrum of bacteria in ABU is similar to species found in uncomplicated or complicated UTIs, depending on the presence of risk factors, as stated by the EAU guidelines 1

Evidence-Based Recommendations Against Treatment

• The EAU guidelines provide strong recommendations against screening or treating asymptomatic bacteriuria in women without risk factors 1
• The EAU guidelines also recommend against screening or treating asymptomatic bacteriuria in patients with well-regulated diabetes mellitus 1
• The Infectious Diseases Society of America (IDSA) guidelines do not recommend treatment for asymptomatic MRSA colonization in any body site 3, 4

Rationale for Non-Treatment

• Clinical studies have shown that ABU may actually protect against superinfecting symptomatic UTIs, according to the EAU guidelines 1
• Treating ABU can lead to selection of antimicrobial resistance, as stated by the EAU guidelines 1
• Treatment may eradicate potentially protective ABU strains, according to the EAU guidelines 1
• Unnecessary antibiotic use contributes to the growing problem of antimicrobial resistance, as stated by the EAU guidelines 1

Specific Considerations for MRSA

• MRSA in urine without symptoms represents colonization rather than infection, according to the EAU guidelines 1
• Treatment of MRSA bacteriuria would require MRSA-specific antibiotics like vancomycin, which have significant side effects and contribute to antimicrobial resistance, as stated by the Annals of Oncology 2

When Treatment Should Be Considered

• The EAU guidelines recommend screening and treating asymptomatic bacteriuria before urological procedures breaching the mucosa 1
• The EAU guidelines also recommend screening and treating asymptomatic bacteriuria in pregnant women 1

Monitoring Recommendations

• The EAU guidelines recommend monitoring a patient with asymptomatic MRSA bacteriuria for development of symptoms (dysuria, frequency, urgency, suprapubic pain) 1
• If persistent growth of urease-producing bacteria is detected, the EAU guidelines suggest considering evaluation for urinary stones 1
• For male patients, the EAU guidelines recommend considering digital rectal examination to investigate possible prostate disease 1