How do I know if I am colonized with Extended-Spectrum Beta-Lactamase (ESBL) bacteria in my urinary tract?

From the Guidelines

To determine if you are colonized with Extended-Spectrum Beta-Lactamase (ESBL) bacteria in your urinary tract, you need a urine culture test specifically looking for ESBL-producing organisms, but routine screening is not recommended for asymptomatic patients due to the risk of promoting antibiotic resistance, as stated in the 2021 AUA/SUFU guideline 1. When considering the diagnosis of ESBL colonization, it's essential to understand that colonization means the bacteria are present but not causing an active infection or symptoms.

• Your healthcare provider will collect a urine sample and send it to a laboratory for culture and sensitivity testing.
• The lab will identify if ESBL-producing bacteria are present and determine which antibiotics would be effective against them.
• If ESBL bacteria are found in your urine without symptoms of a urinary tract infection (such as burning during urination, frequency, urgency, or fever), this indicates colonization rather than infection. The significance of ESBL colonization lies in the fact that these bacteria are resistant to many common antibiotics, including penicillins and cephalosporins, as highlighted in the 2019 IDSA guideline for the management of asymptomatic bacteriuria 1.
• If you're colonized, your doctor may not prescribe antibiotics unless you develop an active infection, as unnecessary antibiotic use can increase resistance.
• However, they may recommend preventive measures like good hygiene practices and increased fluid intake to reduce the risk of developing an active infection. It's also important to note that the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines for the treatment of infections caused by multidrug-resistant gram-negative bacilli, published in 2022, emphasize the need for antimicrobial stewardship and the careful selection of antibiotics in the treatment of ESBL-producing infections 1. Additionally, the 2023 WSES guidelines for the prevention, detection, and management of iatrogenic urinary tract injuries (iUTIs) during emergency digestive surgery recommend adjusting the dose and timing of administration of antibiotics to make the antibiotic treatment effective, and emphasize the importance of antibiotic de-escalation to avoid selecting resistant pathogens without increasing mortality 1.

From the Research

Detection of ESBL Bacteria in Urinary Tract

To determine if you are colonized with Extended-Spectrum Beta-Lactamase (ESBL) bacteria in your urinary tract, several methods and factors can be considered:

• A study published in 2023 2 developed a clinical prediction rule to predict ESBL-producing E. coli in patients with suspected urinary tract infection, which included factors such as being female, having a history of urinary tract infection, and elevated CRP levels.
• The Modified Double Disc Synergy Test (MDDST) can be used to detect ESBL production in urinary isolates of Escherichia coli and Klebsiella pneumoniae 3.
• Risk factors for ESBL-producing E. coli infection include recurrent UTI and female sex 4.
• ESBL-producing E. coli urinary isolates often show high resistance rates to commonly used oral antimicrobial agents, except for nitrofurantoin and fosfomycin 4.

Laboratory Tests

Laboratory tests can be used to detect ESBL-producing bacteria in urine samples:

• The Double Disc Synergy Test (DDST) is a simple and reliable method to detect ESBL production in gram-negative bacilli 3.
• The MDDST, which uses cefepime along with third-generation cephalosporins, can improve ESBL detection in bacteria that co-produce AmpC 3.
• Urine cultures can be used to identify ESBL-producing E. coli and other bacteria 5, 2.

Clinical Considerations

Clinical considerations for detecting ESBL colonization in the urinary tract include:

• Patients with a history of urinary tract infection, recurrent UTI, or those who have been hospitalized or exposed to antibiotics may be at higher risk of ESBL colonization 6, 5, 4.
• The presence of ESBL-producing bacteria in the urinary tract can lead to urinary tract infections, bloodstream infections, and other complications 6, 5.