Peritonitis caused by dematiaceous molds is uncommon but poses a significant threat to patients undergoing peritoneal dialysis (PD), leading to high mortality and morbidity. This report highlights three cases of peritonitis caused by three distinct species of Diaporthe (D. amygdali, D. eucalyptorum, and D. phaseolorum), initially unidentified through conventional culture methods. The nucleotide sequences of internal transcribed spacer regions (ITS), 18S nuclear ribosomal small subunit (SSU), and 28S nuclear ribosomal large subunit (LSU) of the ribosomal DNA gene correctly identified the isolates. Despite early catheter removal and administration of appropriate antifungal medications, all patients experienced fatal outcomes. DNA barcoding emerges as a valuable tool for accurately diagnosing species within the genus of pathogenic microbes, aiding in identifying the root causes of infections. It emphasizes the importance of strict adherence to aseptic techniques during PD exchanges to prevent peritonitis caused by plant-borne pathogens.
