Xanthogranulomatous pyelonephritis caused by methicillin-resistant Staphylococcus aureus

Area of Science:

• Nephrology
• Infectious Diseases
• Pathogen Research

Background:

• Xanthogranulomatous pyelonephritis (XGP) is a rare, chronic bacterial infection of the kidney.
• Typically, XGP is associated with gram-negative bacilli and often linked to kidney stones or obstruction.
• This case explores an atypical presentation of XGP.

Observation:

• A 41-year-old diabetic patient presented with localized xanthogranulomatous pyelonephritis.
• The infection was caused by methicillin-resistant Staphylococcus aureus (MRSA).
• Recurrent bacteremia persisted despite vancomycin treatment, leading to a nephrectomy for diagnosis and cure.

Findings:

• Localized XGP due to S. aureus likely arises from hematogenous spread, unlike gram-negative bacilli-associated XGP.
• This MRSA-induced XGP was not associated with nephrolithiasis or ureteral obstruction.
• The case highlights MRSA as a potential causative agent for XGP.

Implications:

• Recognizing MRSA as a cause of XGP is crucial for effective treatment strategies.
• Understanding the distinct pathogenesis of S. aureus-related XGP can guide clinical management.
• This case underscores the importance of considering emerging nosocomial pathogens in complex infections.