Two cases of pyelonephritis with bacteremia by Staphylococcus epidermidis in male patients with nephrolithiasis: Case reports and a literature review

Abstract

Background: Staphylococcus epidermidis is a common cause of health care-associated bacteremia, especially in patients with an indwelling medical device. However, S. epidermidis is an uncommon causative organism in catheter-associated urinary tract infection, and rare pyelonephritis without any indwelling urinary device. To our knowledge, there are few cases reported of bacteremia secondary to urinary tract infection. We report two cases of pyelonephritis with bacteremia by S. epidermidis in male patients with unilateral nephrolithiasis and review prior case reports.

Case presentation: Case 1: 74-year-old man with a history of diabetes and overactive bladder had fever and pyuria with a right nephrolithiasis on abdominal CT scan. Case 2: 79-year-old man with a history of diabetes and post-myocardial infarction status had fever with a left nephrolithiasis on abdominal CT scan. In both cases, both the urine culture collected at ureteral stenting and blood culture were positive for S. epidermidis. We initiated intravenous antibiotics in these patients in addition to ureteral stenting.

Conclusions: S. epidermidis is acknowledged as an uncommon pathogen that can cause bacteremia secondary to pyelonephritis without an indwelling urinary device. Clinicians should consider the possibility of pyelonephritis due to S. epidermidis if the pathogen is identified in blood and urine in patients with nephrolithiasis.

Keywords: Bacteremia; Coagulase-negativestaphylococci; Nephrolithiasis; Pyelonephritis; Staphylococcus epidermidis; Urinary tract infection.