Peritoneal dialysis-related peritonitis caused by Mycobacterium brisbanense: A case report and literature review

Mycobacterium brisbanense, a rare, rapidly growing, nontuberculous mycobacterium, is typically associated with respiratory infections. Herein, we report the first known case of peritoneal dialysis (PD)-related peritonitis caused by M. brisbanense in a male patient in his 70 s with end-stage renal disease due to chronic glomerulonephritis and renal sclerosis. Despite initial empirical treatment with cefazolin and ceftazidime for co-isolated bacteria (Staphylococcus warneri and Kocuria marina), the symptoms worsened. A subsequent acid-fast bacillus culture of the PD effluent was positive, and the microorganism was identified as M. brisbanense using time-of-flight mass spectrometry and whole-genome sequencing. Antibiotic susceptibility testing revealed susceptibility to all the following administered agents. The patient was successfully treated by PD-catheter removal and intravenous administration of amikacin, imipenem/cilastatin, and oral azithromycin for 40 days, followed by oral azithromycin and sitafloxacin for 153 days. M. brisbanense is a potential opportunistic pathogen in PD-related peritonitis that requires tailored antimicrobial therapy.