In vitro susceptibility of Sporothrix spp. to complexes coordinated with Co(II) and cobalt chloride hexahydrate

Abstract

Sporothrix spp. are the major dimorphic fungus associated with a type of subcutaneous mycosis, sporotrichosis. The limitation of antifungal availability and the past reports of in vitro resistance of Sporothrix spp. clinical isolates makes it important to search for new compounds with antifungal activities. In this study, we therefore evaluate the in vitro activities of complexes coordinated with Co(II) and cobalt chloride hexahydrate against clinical isolates of Sporothrix spp. Broth microdilution test was performed as per M38-A2 from CLSI (2008) in duplicate for 31 clinical isolates of Sporothrix spp. (27 S. brasiliensis e 04 S. schenckii stricto sensu). The antifungal activities of the complexes coordinated with Co(II) and cobalt chloride hexahydrate were detected at a concentration range of 32-128 µg/mL for all isolates. None of the compounds demonstrated any cytotoxicity (to macrophage cells) at the concentration of 200 µg/mL. The activity against Sporothrix spp. recorded in this study instigate the continuity of experimental studies with Co(II) to search for the mechanisms of antifungal action as well as to evaluate its interaction with the commercial antifungal drugs.

Sporothrix brasiliensis: Epidemiology, Therapy, and Recent Developments

“…Regarding in vitro activity, 25 articles described the inhibitory activity of 28 drugs against S. brasiliensis (100% fungal-inhibition criterion): 20 chemicals and 8 repurposed drugs [ 48 , 49 , 51 , 53 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ]. Data about the MIC for each individual drug are shown in Table 1 .…”

“…To this end, with regard to new promising drugs with anti- S. brasiliensis activity, approximately 30 drugs with in vitro inhibitory activity have been described. In addition, some drugs showed anti-biofilm activity of Sporothrix spp., and/or potentiated the activity of commercial antifungal drugs (mainly ITZ, the drug of choice for sporotrichosis treatment), stressing the need for continuing studies in this field of new drug development [ 48 , 49 , 51 , 53 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ].…”