Comparison of antimicrobial resistance in patients with obstructive pyelonephritis associated with ureteral stones and uncomplicated pyelonephritis

This study aimed to investigate the clinical outcomes of causative microorganisms in obstructive pyelonephritis associated with ureteral stones (OPU) and their antibiotic susceptibilities. This retrospective cohort study included female patients diagnosed with community-acquired acute pyelonephritis (APN) at a tertiary-care hospital between 2008 and 2017. A comparison of APN cases associated with the obstruction of the upper urinary tract by ureteral stones and APN cases without complications was performed. Propensity score (PS) matching was used to adjust the heterogeneity within each group. Of the 588 female patients with community-acquired APN, 107 were diagnosed with OPU and 481 with uncomplicated APN. After PS matching, Enterobacteriaceae strains isolated from OPU cases were more resistant to fluoroquinolones (51.9% vs 16.0%, P < .001). Extended-spectrum β-lactamase was detected in 22.2% and 21.0% of the Enterobacteriaceae strains isolated from OPU and uncomplicated APN cases, respectively (P = 1.000). The treatment failure rate was similar in OPU and uncomplicated APN groups (16.0% vs 21.0%, P = .545). Patients with OPU may be empirically treated with antibiotics in accordance with the treatment protocol for general pyelonephritis. Clinicians should exercise caution in prescribing fluoroquinolones for treating OPU.