Abstract
We describe a patient with chronic granulomatous disease and proven Aspergillus fumigatus osteomyelitis of the midfoot, while receiving itraconazole-prophylaxis. The isolate proved resistant to itraconazole as well as voriconazole, and showed reduced susceptibility to posaconazole. Although molecular analysis demonstrated the presence of a 53 base pair tandem repeat in the promoter region for cyp51A, i.e., the gene coding for the target enzyme of the azole antifungals, there were no mutations in the cyp51A gene. Since transformation of the promoter region into wild-type strains did not result in an azole resistant phenotype, a yet unknown mutation was suspected. The patient was treated with extensive surgery and two weeks of caspofungin therapy, followed by one year of posaconazole therapy. He made a complete recovery and did not experience any side effects. Long-term posaconazole proved to be a safe and effective treatment for multi-azole resistant A. fumigatus osteomyelitis in this immunocompromised patient.