Expired Dialysate, Unexpected Pathogen: First Reported Case of Streptomyces Olivaceus Peritonitis in a Peritoneal...

Area of Science:

• Microbiology
• Nephrology
• Infectious Diseases

Background:

• Peritoneal dialysis (PD)-associated peritonitis typically involves skin or enteric bacteria.
• Environmental actinomycetes, like Streptomyces, are rarely implicated in PD peritonitis.
• Streptomyces species are uncommon human pathogens, with no prior molecularly confirmed PD peritonitis cases reported.

Purpose of the Study:

• To report a unique case of PD peritonitis caused by Streptomyces olivaceus.
• To highlight diagnostic challenges associated with atypical organisms in PD peritonitis.
• To underscore the potential risks of expired PD supplies and the importance of molecular diagnostics.

Main Methods:

• A case study of a patient on automated PD presenting with peritonitis symptoms.
• Initial diagnostic workup included Gram stain and Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry.
• Definitive identification of the causative agent was achieved through 16S rRNA gene sequencing.

Main Results:

• The patient developed peritonitis after using an expired dialysate bag.
• Routine cultures and MALDI-TOF were inconclusive, but Gram stain showed filamentous Gram-positive bacilli.
• 16S rRNA gene sequencing confirmed the pathogen as Streptomyces olivaceus.
• The patient recovered after catheter removal and prolonged antimicrobial therapy.

Conclusions:

• This case illustrates diagnostic difficulties with rare pathogens in PD peritonitis, showing limitations of conventional methods.
• Expired PD supplies can be a source of contamination, posing risks, especially in resource-limited settings.
• Molecular diagnostics are crucial for identifying atypical organisms, and enhanced supply chain safeguards are recommended.