In-vitro antifungal susceptibility of the genus Sporothrix and correlation with treatment options for sporotrichosis: a systematic review

Sporotrichosis is an infection with global distribution caused by the dimorphic fungi of the genus Sporothrix, whose main pathogenic species include Sporothrix schenckii, Sporothrix brasiliensis, Sporothrix globosa, and Sporothrix luriei. Itraconazole and amphotericin B are the most used antifungals for the treatment. The aim of this review was to compile the in-vitro susceptibility data of Sporothrix spp. found in literature and correlate this data with the treatment guidelines for sporotrichosis. The systematic review was performed according to the Cochrane methodology and with PICOS (Participants, Intervention, Comparators, Outcomes, Study Design) strategy. Thirty-six studies were included that used the filamentous and/or the yeast phases to perform the susceptibility tests. Three studies that evaluated the association of antifungals using the checkerboard method were also included. The data found were, whenever possible, compared with the defined Epidemiological Cutoff Values (ECVs). Analyzing only the minimum inhibitory concentration (MIC) values, the most effective antifungal in vitro was terbinafine. However, this is not the same result as observed in vivo. Both itraconazole and amphotericin B presented in-vitro activity. However, many studies have shown that isolates can acquire resistance mechanisms to these antifungals (MIC > ECV), which deserves attention. Further studies are needed to translate in-vitro susceptibility data into clinical practice, and also to determine ECVs for more antifungals and Sporothrix species.