Cytological and molecular detection of Scedosporium apiospermum in a patient treated for a Mycobacterium avium complex infection

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

Scedosporium apiospermum lung disease in a patient with nontuberculous mycobacteria

Although tuberculosis is a major underlying cause of pulmonary mycetoma due to Scedosporium apiospermum, little is known about coinfection with nontuberculous mycobacteria (NTM) and S. apiospermum. A 67-year-old man with NTM presented with recurrent haemoptysis. Computed tomography of the chest revealed pulmonary mycetoma in the left upper lobe of the lung, and culture of bronchial washing fluid yielded S. apiospermum. Oral voriconazole therapy ameliorated both haemoptysis and mycetoma findings. As far as we are aware, this is the first reported case of S. apiospermum lung disease in a patient with NTM but without tuberculosis. The possibility of S. apiospermum infection should thus be considered in the differential diagnosis of pulmonary mycetoma. Although S. apiospermum mycetoma resembles aspergilloma, antifungal strategies for these two conditions differ, with the collection of culture specimens such as by bronchoscopy being compulsory for accurate diagnosis and appropriate management of S. apiospermum infection.