A Case of Misidentification of Aspergillus versicolor Complex as Scopulariopsis Species Isolated from a Homograft

Abstract

We report a case of the isolation of the Aspergillus versicolor complex, initially misidentified by morphological characteristics as the Scopulariopsis species, from a homograft with a bicuspidalized pulmonary valve. An eighteen-month-old female, who had critical pulmonary stenosis, underwent pulmonary valve replacement. On postoperative day 8, she developed a fever, which did not respond to empiric broad-spectrum antibiotics. While no definitive source was identified, a filamentous fungus was isolated from the thawed homograft tissue culture prior to implantation on the operation day. The colonies were powdery green with white edges on Sabouraud dextrose agar. Microscopic examination showed septate hyphae with branched conidiophores and chains of spiny conidia, which suggested Scopulariopsis species. After direct sequencing of the internal transcribed spacer (ITS) regions, the fungus was identified as the A. versicolor complex. To our knowledge, the isolation of the A. versicolor complex from a homograft valve has not been previously described. This case shows that laboratory staff should be aware that microscopic morphology of the A. versicolor complex can resemble that of a number of other genera, including Scopulariopsis species.