Xanthogranulomatous Pyelonephritis Caused by Stenotrophomonas maltophilia—The First Case Report and Brief Review

Abstract

Xanthogranulomatous pyelonephritis (XGP) represents a rare and severe pathology secondary to chronic urinary obstruction and recurrent infections. Commonly, this condition leads to loss of kidney function, and frequently, surgical approach is the only optional treatment. Proteus mirabilis and Escherichia coli are the most frequent pathogens associated with XGP. The actual changes in the pathogen’s characteristics increased the risk of newly acquired infections once considered opportunistic. Stenotrophomonas malthophilia is one of those agents more related to immunocompromised patients, presenting an increased incidence and modified antibiotic resistance profile in the modern era. This case report presents a healthy female patient with an underlying renal stone pathology diagnosed with XGP related to S. maltophilia urinary infection. After a complete biological and imagistic evaluation, the case was treated as pyonephrosis. Empirical antibiotic administration and a surgical approach were considered. A total nephrectomy was performed, but the patient’s condition did not improve. The patient’s status improved when specific antibiotics were administered based on the bacterial identification and antibiotic susceptibility pattern of drained perinephric fluid. Levofloxacin and Vancomycin were considered the optimal combination in this case. The histopathological examination revealed XGP secondary to chronic renal stone. The present study describes the first case of XGP related to an aerobic Gram-negative pathogen such as S. maltophilia, once considered opportunistic, in an apparently healthy female adult.

Combination Therapy versus Monotherapy in the Treatment of Stenotrophomonas maltophilia Infections: A Systematic Review and Meta-Analysis

“…Of the 28 articles, 11 were excluded due to inappropriate comparisons ( n = 4), in vitro studies ( n = 5), editorial ( n = 1), and no response from author for incomplete data ( n = 1). A total of 17 studies, published between 1996 and 2022, comprised of case reports ( n = 9), case series ( n = 4), and cohort studies ( n = 4) [ 10 , 11 , 12 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] were included in the review. Details of the included studies’ case reports/case series are summarized in Table 1 and Supplementary Table S3 , and four cohort studies [ 25 , 26 , 27 , 28 ] are summarized in Table 2 and Supplementary Table S4 .…”

Clinical Presentation, Microbiological Characteristics, and Their Implications for Perioperative Outcomes in Xanthogranulomatous Pyelonephritis: Perspectives from a Real-World Multicenter Practice

“…Urine cultures most often reveal Escherichia coli and Proteus mirabilis , but sometimes uncommon and opportunistic pathogens too [ 4 ].…”