DIVE DEEPER and E. coli

FAQs about urinary tract infection (UTI)

DIVE DEEPER and E. coli

FAQs about urinary tract infection (UTI)

DIVE DEEPER and E. coli

Show all

  • 1. How are UTIs classified?

    Currently, there is no standard definition of UTI that is widely accepted in the medical community.1-4 UTIs can be classified as uncomplicated UTI (uUTI) or complicated UTI (cUTI); not all organizations distinguish between the 2 using the same criteria.

    Without standardization, the variability among UTI definitions may cause confusion about the diagnosis and treatment of UTIs.

  • 2. How is an uncomplicated UTI (uUTI) defined?

    The Infectious Diseases Society of America (IDSA) treatment guidelines suggest that a uUTI is an infection of the urinary tract in a non-pregnant woman without urologic abnormalities or co-morbidities and without fever, flank pain, or other symptoms suggestive of an infection that extends beyond the bladder.4

  • 3. How is a complicated UTI (cUTI) defined?

    The IDSA treatment guidelines suggest a cUTI is one that occurs in the presence of a structural or functional abnormality of the urinary tract and presents with signs and symptoms of infection extending beyond the bladder, such as fever and flank pain.4

  • 4. Why is UTI more common in women?

    UTIs are more common in women because the urethra is shorter and the proximity of the urethral opening to the vaginal cavity and the rectum make it easier for bacteria to enter the urinary tract.5,6

  • 5. What organisms cause uncomplicated UTI (uUTI)?

    uUTI is primarily caused by uropathogenic strains of Escherichia coli (E. coli). Other species of Enterobacteriaceae, such as Proteus mirabilis, Klebsiella pneumoniae, and Staphylococcus saprophyticus, can also, but less commonly, cause UTI.4

  • 7. What is the difference between relapse and recurrence?

    Recurrence is defined as reinfection, meaning that a different strain of bacteria caused the UTI or the UTI recurred after the initial 2 weeks of antibiotic treatment. Relapse occurs with the same causative pathogen within 2 weeks of antibiotic treatment. The distinction between UTI recurrence and relapse is important as it may affect diagnosis or treatment.1, 2

  • 8. What are uropathogenic E. coli?

    Uropathogenic strains of E. coli differ from non-pathogenic, commensal E. coli strains in that they possess virulence genes that code for adherence and colonization factors that increase their ability to infect the urinary tract.7

  • 9. What are ESBL+ E coli and how are they contributing to the problem of resistance?

    Extended-spectrum β-lactamase producing (ESBL+) E. coli produce enzymes that can break down the
    β-lactam ring of many penicillins and cephalosporins rendering them ineffective.8

    ESBL+ E. coli are contributing to the problem of rising antibiotic resistance.8

    In addition, some ESBL phenotypes may also be co-resistant to other antibiotic classes and transfer these genes to other E. coli. In doing so,
    E. coli may develop resistance to fluoroquinolones, aminoglycosides, and trimethoprim-sulfamethoxazole.8,9

  • 10. What symptoms of UTI do patients report as problematic?

    In a large observational study of 511 women, nearly 80% reported daytime frequency as problematic and more than 50% reported dysuria, urgency, and nocturia as problematic.10

    Data collected from an observational study of non-pregnant adult females with suspected uUTI in which 511/830 returned a completed 14-day symptom diary. Patients’ self-reported symptoms were rated on a scale of 0-6 with a score of 3-6 indicating the symptom was problematic (ie, moderately bad or worse). This study was part of a larger diagnostic study.10

  1. ACOG Committee on Practice Bulletins. ACOG practice bulletin. Clinical management guidelines for obstetrician–gynecologists. March 2008; Number 91. Accessed August 1, 2023. http://www.losolivos-obgyn.com/info/urology/urinary_tract_infection.pdf
  2. Brubaker L, Carberry C, Nardos R, Carter-Brooks C, Lowder JL. American Urogynecologic Society best-practice statement: recurrent urinary tract infection in adult women. Female Pelvic Med Reconstr Surg. 2018;24(5):321-335.
  3. Anger J, Lee U, Ackerman AL, et al. Recurrent uncomplicated urinary tract infections in women: AUA/CUA/SUFU guideline. J Urol. 2019;202(2)(suppl 1):1-36.
  4. Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52(5):e103-e120.
  5. Urinary Tract Infection. Centers for Disease Control and Prevention. October 6, 2021. Accessed March 16, 2023. https://www.cdc.gov/antibiotic-use/uti.html
  6. Foxman B. The epidemiology of urinary tract infection. Nat Rev Urol. 2010;7(12):653-660.
  7. Palaniappan RUM, Zhang Y, Chiu D, et al. Differentiation of Escherichia coli pathotypes by oligonucleotide spotted array. J Clin Microbiol. 2006;44(4):1495-1501.
  8. Reygaert WC. An overview of the antimicrobial resistance mechanisms of bacteria. AIMS Microbiol. 2018;4(3):482-501.
  9. Critchley IA, Cotroneo N, Pucci MJ, Mendes R. The burden of antimicrobial resistance among urinary tract isolates of Escherichia coli in the United States in 2017. PLoS One. 2019;14(12):e0220265.
  10. Little P, Merriman R, Turner S, et al. Presentation, pattern, and natural course of severe symptoms, and role of antibiotics and antibiotic resistance among patients presenting with suspected uncomplicated urinary tract infection in primary care: observational study. BMJ. 2010;340:b5633.