From the Guidelines
Asymptomatic bacteriuria (ASB) with 20,000 CFU/mL of Klebsiella pneumoniae in a urine culture should generally not be treated with antibiotics. The recommended approach is to withhold antimicrobial therapy in most patient populations when there are no urinary symptoms present, as stated in the 2019 guideline by the Infectious Diseases Society of America 1. This recommendation applies to healthy non-pregnant women, men without urologic abnormalities, elderly patients in community or long-term care settings, and patients with diabetes, spinal cord injuries, or indwelling urinary catheters.
The rationale for not treating ASB is that antibiotic therapy does not reduce complications or prevent symptomatic infections in most populations, while it does increase adverse effects, healthcare costs, and antimicrobial resistance, as noted in the guideline by the American Urological Association 1. Additionally, the bacterial count of 20,000 CFU/mL is relatively low (significant bacteriuria is typically defined as ≥100,000 CFU/mL), further supporting the decision to withhold treatment.
Some key points to consider include:
- The only populations that should receive treatment for ASB are pregnant women and patients undergoing urologic procedures where mucosal bleeding is anticipated, as recommended by the Infectious Diseases Society of America 1.
- Treatment of ASB may actually increase the risk of symptomatic UTI, as suggested by a recent nonblinded, randomized clinical trial 1.
- The use of antibiotics should be guided by the principles of antimicrobial stewardship, balancing the benefits of treatment with the risks of adverse effects and resistance, as emphasized in the guideline by the American Urological Association 1.
If the patient's clinical status changes and urinary symptoms develop, then reassessment and potential treatment would be warranted. However, in the absence of symptoms, withholding antibiotic treatment is the recommended approach, as supported by the guidelines from the American Urological Association 1 and the Infectious Diseases Society of America 1.
From the Research
Treatment Approach for Asymptomatic Bacteriuria
The treatment approach for asymptomatic bacteriuria (ASB) with 20,000 Colony-Forming Units per milliliter (CFU/mL) Klebsiella pneumoniae in a urine culture (UC) without symptoms is primarily focused on not treating the condition in most cases, due to the potential for antibiotic-associated morbidity and the selection of antibiotic resistance 2, 3, 4, 5, 6.
Specific Patient Groups
- Pregnant Women: Treatment of ASB is recommended in pregnant women, as it can decrease the risk of symptomatic UTI, low birthweight, and preterm delivery 2, 3, 6.
- Patients Undergoing Urological Procedures: Treatment of ASB is recommended prior to urological procedures that breach the mucosa, such as transurethral resection surgery, to reduce the risk of postoperative UTI 2, 3, 6.
- Patients with Recurrent UTI: Treatment of ASB is not recommended in patients with recurrent UTI, as it may not provide any benefit and can even be harmful by selecting for antibiotic-resistant bacteria 4, 6.
- Other Patient Groups: Treatment of ASB is not recommended in other patient groups, including patients with diabetes mellitus, postmenopausal women, elderly institutionalized patients, patients with renal transplants, or patients prior to joint replacement, as there is no evidence of benefit and potential harm 3, 6.
Key Considerations
- Antibiotic Stewardship: The treatment of ASB should be guided by the principles of antibiotic stewardship, aiming to minimize unnecessary antibiotic use and reduce the risk of antibiotic resistance 2, 3, 4, 5, 6.
- Urine Culture: Urine culture is the gold standard for detecting UTI, and asymptomatic bacteriuria should not be treated with antibiotics unless there are specific indications, such as pregnancy or upcoming urological surgery 5.