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🦠microbiology review

UPEC

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

UPEC, or Uropathogenic Escherichia coli, is a pathogenic strain of the Gram-negative bacterium Escherichia coli that is a leading cause of urinary tract infections (UTIs). UPEC is a member of the Proteobacteria phylum and has evolved specialized virulence factors that allow it to successfully colonize and infect the human urinary tract.

5 Must Know Facts For Your Next Test

  1. UPEC is a member of the Proteobacteria phylum, which is the largest and most diverse phylum of Gram-negative bacteria.
  2. UPEC is the leading cause of community-acquired urinary tract infections, accounting for up to 90% of all UTI cases.
  3. UPEC expresses a range of virulence factors, including adhesins, toxins, and iron acquisition systems, which allow it to colonize and persist in the urinary tract.
  4. The ability of UPEC to form intracellular bacterial communities and enter a dormant state contributes to its recurrent nature and resistance to antibiotic treatment.
  5. Certain UPEC strains have acquired antibiotic resistance genes, making them increasingly difficult to treat and posing a significant public health concern.

Review Questions

  • Explain the role of UPEC as a member of the Proteobacteria phylum and its significance in causing urinary tract infections.
    • As a member of the Proteobacteria phylum, UPEC is a Gram-negative bacterium that has evolved specialized virulence factors that allow it to successfully colonize and infect the human urinary tract. UPEC is the leading cause of community-acquired urinary tract infections, accounting for up to 90% of all UTI cases. Its ability to adhere to, invade, and persist within the urinary tract, coupled with its capacity to form intracellular bacterial communities and enter a dormant state, contribute to the recurrent and difficult-to-treat nature of UPEC-associated UTIs.
  • Describe the key virulence factors that enable UPEC to cause urinary tract infections and how they contribute to the pathogenesis of the disease.
    • UPEC possesses a range of virulence factors that enhance its ability to cause urinary tract infections. These include adhesins that allow the bacteria to attach to the urinary tract epithelium, toxins that can damage host cells, and iron acquisition systems that enable UPEC to obtain essential nutrients within the host environment. Additionally, the ability of UPEC to form intracellular bacterial communities and enter a dormant state helps the pathogen evade host immune defenses and antibiotic treatment, leading to recurrent infections. Understanding the specific virulence factors of UPEC is crucial for developing effective strategies to prevent and treat UTIs caused by this important Proteobacterial pathogen.
  • Evaluate the public health significance of UPEC's increasing antibiotic resistance and discuss potential approaches to address this growing concern.
    • The rise of antibiotic-resistant UPEC strains poses a significant public health concern, as it makes these infections increasingly difficult to treat. UPEC's ability to acquire resistance genes threatens to undermine the effectiveness of commonly used antibiotics for UTI management. This is particularly problematic given the high prevalence of UPEC-associated UTIs and the potential for these infections to lead to more serious complications, such as kidney infections and sepsis. Addressing this challenge will require a multifaceted approach, including the development of novel antimicrobial therapies, improved diagnostic tools to guide targeted treatment, and the implementation of antimicrobial stewardship programs to preserve the efficacy of existing antibiotics. Additionally, further research into the underlying mechanisms of UPEC virulence and antibiotic resistance may inform the design of more effective prevention and intervention strategies against this important Proteobacterial pathogen.