Magnusiomyces clavatus fungemia treated with combination antifungals including isavuconazole in an immunocompromised pediatric patient: a case report.
McPherson Amanda Z AZ, Miller Matthew M, Rytlewski Kacie K, Bacon Samantha S et al.
Magnusiomyces clavatus, formerly Saprochaete clavata or Geotrichum clavatum, is an ascomycetous yeast found in the environment as well as the gastrointestinal and respiratory tracts of humans. It has been described as an emerging, albeit rare, cause of invasive fungal disease affecting immunocompromised patients. Intrinsic resistance to fluconazole and echinocandins has been theorized; however, little else is known regarding optimal treatment regimens for this opportunistic pathogen. To our knowledge, only 13 infectious cases have been described in pediatric patients, all of which utilized a combination of antifungals including liposomal amphotericin B (LAmB) and voriconazole with or without flucytosine (5-FC). Here we report a case of a 4-year-old, 12.3 kg, female patient who immigrated from Ukraine and was admitted to our institution for an allogeneic umbilical cord blood transplant in the setting of bone marrow failure secondary to Fanconi anemia. On day +6 after cell transplantation, the patient developed febrile neutropenia found to be because of invasive M. clavatus fungemia on day +7. The patient was empirically treated with LAmB, micafungin, and posaconazole (POS), the latter of which failed to reach therapeutic levels. Ultimately, our patient defervesced and cleared blood cultures after transitioning LAmB to 5-FC, followed by definitive treatment with isavuconazole (ISA) monotherapy. To our knowledge, this is the first case of pediatric M. clavatus ultimately treated with 5-FC plus POS followed by ISA alone.