In vitro isavuconazole activity against Sporothrix brasiliensis suggests its efficacy in some severe sporotrichosis cases

Background:Sporothrix brasiliensis causes sporotrichosis, an important infection in some groups of patients. Aims: This work was designed to investigate the effects of isavuconazole against this species. Methods: An antifungal susceptibility test was performed to compare MIC values with other antifungal drugs used to treat sporotrichosis. A checkerboard assay was performed to understand isavuconazole interactions. Furthermore, isavuconazole growth inhibition on an itraconazole-resistant strain was tested. Results: Isavuconazole had similar MICs to other azoles against S. brasiliensis, presenting fungistatic activity. Isavuconazole did not interact in vitro with antifungals or immunosuppressive drugs and inhibited the growth of an itraconazole-resistant strain. Conclusion: Isavuconazole inhibits S. brasiliensis, its pharmacologic characteristics make it a candidate for patients with sporotrichosis and it may be useful to combat sporotrichosis caused by resistant isolates.Isavuconazole is a drug that remains largely unstudied, especially for fungal infections that develop at the site of a break in the skin, such as a wound. The authors conducted experiments in order to study and evaluate isavuconazole's effects on sporotrichosis; in particular whether the drug could stop or kill these fungi. The results show that isavuconazole is highly effective against Sporothrix brasiliensis, the main species that causes sporotrichosis in Brazil and other countries in South America, by inhibiting the fungal growth. Isavuconazole was also effective for different strains that were not inhibited by other drugs. This is important because, in the future, it could improve the treatment of sporotrichosis.