Comparison of Antimicrobial Resistance in Patients with Obstructive Pyelonephritis Associated with Ureteral Stones and Uncomplicated Pyelonephritis

Abstract Background This study aimed to investigate the clinical outcomes and antibiotic susceptibilities of causative microorganisms in patients with obstructive pyelonephritis associated with ureteral stones (OPU). Methods This retrospective cohort study included female patients diagnosed with community-acquired acute pyelonephritis (APN) at a tertiary care hospital from 2008 to 2017. Cases of APN associated with obstruction of the upper urinary tract due to the presence of ureteral stones and cases of APN without complications were compared. Propensity score matching was used to adjust for heterogeneity within each group. Results Of the 588 female patients with community-acquired APN, 107 patients were diagnosed with OPU and 481 patients were diagnosed with uncomplicated APN. Propensity score matching revealed that Enterobacteriaceae strains isolated from OPU cases were more resistant to fluoroquinolones (51.9% vs. 16.0%, p < 0.001). Extended-spectrum β-lactamase was detected in 22.2% and 21.0% of the Enterobacteriaceae strains isolated from OPU cases and uncomplicated APN cases, respectively (p = 1.000). The treatment failure rate was similar in the OPU and uncomplicated APN groups (16.0% vs. 21.0%, p = 0.545). Conclusions Antibiotic treatment for patients with OPU may be empirically selected in accordance with the treatment protocol for general pyelonephritis. Clinicians should exercise caution before prescribing fluoroquinolones for the treatment of OPU.