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Presentation

An elderly patient with an extensive cardiac history presented with a chief complaint of new dyspnea. A transesophageal echocardiogram revealed a new vegetation on the mitral bioprosthetic valve. The patient was taken to surgery, and half of the explanted mitral bioprosthetic valve was submitted to the microbiology laboratory where a Gram stain, fungal smear, tissue culture and fungal culture were performed.

The fungal smear on the primary tissue specimen using a calcofluor stain revealed a heavy organism burden with large yeast forms, septate hyphae and pseudohyphae. On day 5, white mold colonies grew on the sheep blood agar in bacteriology and the potato dextrose agar with chloramphenicol (PDACH) in mycology. The tape prep with Lactophenol Cotton Blue stain revealed spherical smooth-walled microconidia and round macroconidia with short cylindrical projections. The species identification was confirmed with MALDI-TOF MS utilizing the Bruker database.

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Author Information

Bethany Burns, D.O., Medical Microbiology Fellow, Cleveland Clinic.