Itraconazole is the first choice for treating
sporotrichosis.
Amphotericin B is indicated for severe and disseminated forms. The aim of the study was to evaluate the antifungal susceptibility of Sporothrix brasiliensis strains isolated from patients with severe
sporotrichosis treated with
amphotericin B and correlate with clinical outcomes. Clinical and epidemiological data were obtained from severe
sporotrichosis cases caused by S. brasiliensis. Antifungal susceptibility tests against
amphotericin B,
itraconazole,
terbinafine,
posaconazole, and 5-flucytosine were performed. Moreover, possible synergisms between
amphotericin B and
posaconazole or 5-flucytosine were assessed. Relationships between clinical and laboratorial data were then analyzed. Forty-six S. brasiliensis isolates from 37 patients were studied. Clinical forms included disseminated (94.6%) and disseminated cutaneous
sporotrichosis (5.4%). The median treatment time was 784 days (range: 7 to 3115 days). Cure occurred in 45.9% of the cases and death due to
sporotrichosis in 24.3%. Forty-three (93.5%) S. brasiliensis isolates were classified as wild-type for all the antifungals tested according to their in vitro antifungal susceptibility. There was no synergism for the combinations studied. Finally, we found no association between higher Minimal Inhibitory Concentration (MIC) values of
amphotericin B or
itraconazole with unfavorable outcomes; however, there were higher MIC values of
itraconazole in strains isolated from alcoholic patients. Possibly, clinical factors, such as the extent of dissemination, immunosuppression, and late treatment onset, are the main determinants of patient outcomes, rather than antifungal resistance. The current study suggests that the need to use
amphotericin B therapy is not associated with the emergence of S. brasiliensis resistant strains.