Analysis of Pathogenic Bacteria, Drug Resistance and Treatment of Emphysematous Pyelonephritis: A Case Series

Purpose: Emphysematous pyelonephritis (EPN) is a rare, acute, gas-producing necrotizing infection of the kidney. This study aims to improve the understanding of EPN, optimize diagnostic and therapeutic strategies, reduce the incidence of severe infections, and improve patient prognosis. Patients and Methods: Patients with a definitive diagnosis of EPN confirmed by computed tomography (CT) were retrospectively reviewed between December 2012 and May 2025. Patient demographics, clinical characteristics, treatment approaches, and outcomes were evaluated. Representative imaging findings were presented, along with an analysis of pathogenic bacteria and antimicrobial resistance in EPN patients. Results: This series includes 15 patients with EPN, representing the largest single-center cohort reported from mainland China in the past 30 years. Body fluid cultures identified 12 pathogenic bacterial strains, with Escherichia coli being the most prevalent (66.7%, 8/12), followed by Klebsiella pneumoniae (25.0%, 3/12) and Pseudomonas aeruginosa (8.3%, 1/12). Multi-drug resistance was observed in 75.0% (9/12) of strains. Drug susceptibility testing showed 100% susceptibility to amikacin (n=12), cefotetan (n=5), and cefoperazone-sulbactam (n=8). Imipenem (n=11), meropenem (n=11), and piperacillin-tazobactam (n=11) demonstrated a susceptibility rate of 91.7%. Overall, 86.7% (13/15) of patients were cured, while 13.3% (2/15) died. Conclusion: We recommend the use of sensitive antibiotics as early as possible, combined with fluid resuscitation, blood glucose control, supportive care, and early minimally invasive therapy. Keywords: Emphysematous pyelonephritis, body fluid cultures, pathogenic bacteria, drug susceptibility analysis, minimally invasive therapy