Rare Urinary Tract Infection with Streptococcus Mitis/Oralis following Ureteroscopy in a Patient with Urinary Stones and Ureteral Stenosis

Introduction: Streptococcus mitis/oralis are species of the Viridans group streptococci. Viridans group streptococci (VGS) are a group of anaerobic Gram-positive bacteria with alpha-hemolytic characteristics that are commonly found in the mouth, upper respiratory tract, and gastrointestinal system. VGS is not a common pathogen in urinary tract infections. Ureteroscopy and percutaneous nephrolithotomy (PCNL) are standard treatments for urinary stones. Although these procedures are generally safe, post-operative infections remain a common complication.Case presentation: Case Presentation: A ۴۹-year-old female presented with bilateral flank pain. Based on the patient's symptoms and examinations, paraclinical investigations were performed, which showed bilateral ureteral stones and elevated serum creatinine levels (Cr=۱.۸۸). The patient underwent ureteroscopy, which resulted in the left ureteral stones being broken and removed. However, right ureteroscopy was unsuccessful due to kinking and severe stenosis. Bilateral double-J stent placement and right nephrostomy were performed. One month later, the patient's double-J stents were removed, and the left ureter was clear on ureteroscopy. Right ureteroscopy showed urinary stones and a large amount of bezoar in the proximal ureter and right renal pelvis. The patient finally underwent PCNL. During surgery, pelvic urine and bezoar samples were sent to the laboratory for examination for fungal and bacterial agents and Mycobacterium tuberculosis. The culture results were positive for Streptococcus mitis/oralis, and according to the antibiogram results, the patient received antibiotic treatment (Meropenem during hospitalization and Amoxicillin-Clavulanic acid after discharge). One month after PCNL, the right double-J stent was removed, and ureteroscopy showed no stones or bezoars with significant improvement of ureteral stricture. The patient's symptoms resolved, and serum creatinine improved to ۱.۵.Conclusion: Although Streptococcus mitis/oralis is an uncommon cause of UTIs after ureteroscopy, it should be considered a potential pathogen in patients with multiple risk factors such as urinary catheterization, prolonged urinary obstruction, and multiple urological procedures.

کلیدواژه ها:

renal calculi ، streptococcus viridans ، UTI ، Ureteroscopy