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Updated: May 17, 2026

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis
Published on: July 18, 2017
[Pyelonephritis]
Cristiana Rollino1, Giulietta Beltrame, Michela Ferro
1Nefrologia e Dialisi, Ospedale S.G. Bosco, Torino - Italy.
Insights
Acute pyelonephritis (APN), often caused by E. coli, is a common kidney infection. While typically treatable with antibiotics, imaging like CT or MRI is crucial for detecting serious complications such as abscesses.
Area of Science:
- Nephrology
- Infectious Diseases
- Urology
Context:
- Acute pyelonephritis (APN) is a common bacterial kidney infection, primarily affecting women.
- Escherichia coli (E. coli) is the predominant causative agent.
- Risk factors include sexual activity, genetic predisposition, advanced age, and urinary tract instrumentation.
Purpose:
- To review the etiology, diagnosis, treatment, and long-term outcomes of acute pyelonephritis in adults.
- To highlight the diagnostic utility of advanced imaging techniques.
- To discuss the management of complications like renal abscesses.
Summary:
- Diagnosis is often clinical, but Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) enhance accuracy and detect abscesses.
- Treatment involves fluoroquinolones or extended-spectrum cephalosporins for 10-14 days.
- Renal abscesses are underestimated complications requiring CT/MRI evaluation; drainage is reserved for large abscesses, with medical management successful in most cases.
Impact:
- Early and accurate diagnosis, including the use of CT/MRI, can prevent severe complications.
- Appropriate antibiotic selection and duration ensure favorable long-term outcomes for most adult patients.
- Understanding the prevalence and management of renal abscesses improves patient care and reduces morbidity.
Abstract:
Acute pyelonephritis (APN) is a frequent pathological condition. Its etiology is prevalently due to E. coli and risk factors include sexual activity, genetic predisposition, old age and urinary instrumentation. No correlation between APN and vesicoureteral reflux has been established in adults. The diagnosis of APN is usually clinical, but computed tomography (CT) and magnetic resonance imaging (MRI) allow a more precise definition and can document evidence of abscesses. Severe cases should be treated with a fluoroquinolone or an extended-spectrum cephalosporin. Treatment should last 10-14 days. The long-term evolution of APN is prevalently favorable in adults, even though formation of cortical scars and development of macroalbuminuria and renal failure have been described. The formation of renal abscesses is underestimated and must be evaluated by CT or MRI. Abscesses need to be drained only when they are large, and medical treatment is successful in the majority of cases.
Related Concept Videos
Acute Pyelonephritis I: Introduction
Acute Pyelonephritis II: Diagnostic Studies and Management
Urinary Tract Infection II: Pathophysiology
Urinary Tract Infection I: Introduction
Urinary Tract Infection III: Diagnostic Studies and Interprofessional Care
Imaging Studies V: Intravenous Urography and Retrograde Pyelography

