Lautropia mirabilis-Induced Peritoneal Dialysis-Associated Peritonitis: A Case Report and Literature Review

Background: Lautropia mirabilis is an uncommon Gram-negative facultative anaerobic bacterium primarily colonizing the oral cavity and upper respiratory tract. Peritoneal dialysis-associated peritonitis (PDAP) caused by this organism is exceedingly rare, with only three previously published cases. Case presentation: We report a 49-year-old woman receiving continuous ambulatory peritoneal dialysis who presented with cloudy dialysate and abdominal pain. Peritoneal effluent analysis revealed a leukocyte count of 16,522 cells/µL, with 85% polymorphonuclear leukocytes, accompanied by an elevated serum C-reactive protein level of 42.77 mg/L. L. mirabilis was isolated from the dialysate and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing. Following intraperitoneal antimicrobial treatment with gentamicin and subsequently ceftazidime, the patient’s symptoms improved. No recurrence of peritonitis was documented during follow-up. A review of the three previously reported cases highlights similarities in clinical presentation but differences in microbiological identification and antimicrobial management. Conclusions: L. mirabilis should be recognized as a potential, albeit rare, cause of PDAP. This case highlights the value of appropriate culture conditions combined with molecular identification for detecting unusual pathogens and emphasizes the importance of integrating microbiological findings with clinical and laboratory responses when guiding treatment.