Case Report About the Identification of Blastocystis and Nakaseomyces glabratus in an Infected Sacral Ulcer: In the Wrong Place with the Right Assistance

Pressure ulcers may harbor diverse microorganisms, but the significance of intestinal microeukaryotes in these lesions remains poorly understood. We report the concurrent detection of Blastocystis subtype 1 (ST1) and Nakaseomyces glabratus in a sacral pressure ulcer in a bedridden adult woman. The lesion was identified during a diarrheal episode and rapidly progressed, prompting investigation for cutaneous amebiasis. Neither microscopy nor complementary Entamoeba-targeted PCR provided evidence of amebic involvement in the ulcer exudate. However, stained smears revealed yeast-like cells and rounded granular structures suggestive of Blastocystis. Targeted PCR sequencing and phylogenetic analyses identified Blastocystis ST1 and N. glabratus. This unusual finding highlights the value of combining microscopy with molecular identification to characterize unexpected microorganisms in pressure ulcers. Fecal introduction and interactions within the polymicrobial wound environment plausibly explain their concurrent presence; however, we did not demonstrate viability, established colonization, biofilm participation, or a contribution to ulcer progression or the fatal outcome.