Development of a quantitative PCR detecting Cunninghamella bertholletiae to help in diagnosing this rare and aggressive mucormycosis.

ABSTRACT

Mucormycosis is an invasive mold infection, frequently fatal in immunocompromised patients. We report the case of a patient with chronic lymphocytic leukemia admitted to the hematology unit for febrile aplasia. Pulmonary lesions suggesting a fungal infection expanded/increased despite a combination of posaconazole and liposomal amphotericin B. The fungal biomarkers performed repeatedly were negative. At D65 after chemotherapy a bronchial biopsy was positive for Cunninghamella bertholletiae. The patient died despite appropriate antifungal management. A qPCR targeting Cunninghamella was developed a posteriori, and a retrospective analysis showed that a sample was positive more than 30 days before culture-based identification could be made.