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April 1991

Periodic Acid-Schiff-Positive Organisms in Primary Cutaneous Bacillus cereus Infection: Case Report and an Investigation of the Periodic Acid-Schiff Staining Properties of Bacteria

Author Affiliations

From the Departments of Dermatology (Drs Khavari, Bolognia, and Shapiro) Laboratory Medicine (Dr Edberg and Ms Grimshaw), and Pathology (Dr Eisen), Yale University School of Medicine, New Haven, Conn.

Arch Dermatol. 1991;127(4):543-546. doi:10.1001/archderm.1991.04510010111013

•Primary cutaneous Bacillus cereus infection frequently presents as a single necrotic bulla on the extremity of an immunocompromised patient. In lesional biopsy specimens and smears, the large gram-positive rods of B cereus may be mistaken for Clostridium species. This is a potentially serious error, as Bacillus species are resistant to penicillin and other β-lactam antibiotics. We studied a case in which large periodic acid-Schiff-staining organisms were seen in the biopsy specimen from a necrotic bulla on the finger of a neutropenic patient with diffuse large cell lymphoma. The tissue biopsy specimen subsequently yielded a pure culture of B cereus. Staining with periodic acid-Schiff was then performed on a series of bacterial species in human tissue and from smears of culture colonies. The following bacterial species were found to be consistently periodic acid-Schiff positive after diastase digestion: B cereus, Corynebacterium diphtheriae, Propionibacterium acnes, Klebsiella pneumoniae, and Micrococcus luteus.