OBJECTIVES: Antifungal treatment of uncommon filamentous fungal infections is problematic. This study determined the in vitro susceptibility of miltefosine, as a single agent and in combination with posaconazole or voriconazole, against these pathogens. METHODS: Susceptibility to miltefosine of 34 uncommon filamentous fungi was tested using CLSI broth microdilution M38-A2 methodology. Twenty isolates were studied for potential synergy using miltefosine/posaconazole and miltefosine/voriconazole combinations and the chequerboard microdilution assay. RESULTS: MICs of miltefosine were high (in general, >8 mg/L) for most isolates compared with amphotericin B, echinocandins and the azoles. Miltefosine had greatest activity against Scedosporium spp., Lichtheimia corymbifera and Rhizomucor sp. (MICs ≤ 4 mg/L). Miltefosine in combination either with posaconazole or voriconazole demonstrated synergy [fractional inhibitory concentration index (FICI) ≤ 0.5] in 12 instances (11 isolates): miltefosine/posaconazole combinations were synergistic against 3 of 4 Fusarium oxysporum strains (FICI range 0.37-0.5) and 5 of 10 mucormycete strains (FICI range 0.06-0.5). The combination of voriconazole with miltefosine showed synergy against one Scedosporium prolificans isolate and three mucormycetes-a single strain each of L. corymbifera, Rhizopus oryzae and Rhizomucor sp. No antagonism was observed. CONCLUSIONS: Miltefosine demonstrated synergy in 8/20 (40%) and 4/20 (20%) instances when combined with posaconazole and voriconazole, respectively. Synergy was most often observed against F. oxysporum and the mucormycetes. Study of miltefosine/azole combinations as a novel antifungal approach is indicated.
OBJECTIVES: Antifungal treatment of uncommon filamentous fungal infections is problematic. This study determined the in vitro susceptibility of miltefosine, as a single agent and in combination with posaconazole or voriconazole, against these pathogens. METHODS: Susceptibility to miltefosine of 34 uncommon filamentous fungi was tested using CLSI broth microdilution M38-A2 methodology. Twenty isolates were studied for potential synergy using miltefosine/posaconazole and miltefosine/voriconazole combinations and the chequerboard microdilution assay. RESULTS: MICs of miltefosine were high (in general, >8 mg/L) for most isolates compared with amphotericin B, echinocandins and the azoles. Miltefosine had greatest activity against Scedosporium spp., Lichtheimia corymbifera and Rhizomucor sp. (MICs ≤ 4 mg/L). Miltefosine in combination either with posaconazole or voriconazole demonstrated synergy [fractional inhibitory concentration index (FICI) ≤ 0.5] in 12 instances (11 isolates): miltefosine/posaconazole combinations were synergistic against 3 of 4 Fusarium oxysporum strains (FICI range 0.37-0.5) and 5 of 10 mucormycete strains (FICI range 0.06-0.5). The combination of voriconazole with miltefosine showed synergy against one Scedosporium prolificans isolate and three mucormycetes-a single strain each of L. corymbifera, Rhizopus oryzae and Rhizomucor sp. No antagonism was observed. CONCLUSIONS:Miltefosine demonstrated synergy in 8/20 (40%) and 4/20 (20%) instances when combined with posaconazole and voriconazole, respectively. Synergy was most often observed against F. oxysporum and the mucormycetes. Study of miltefosine/azole combinations as a novel antifungal approach is indicated.
Authors: Erico S Loreto; Juliana S M Tondolo; Daniele C Oliveira; Janio M Santurio; Sydney H Alves Journal: Antimicrob Agents Chemother Date: 2018-02-23 Impact factor: 5.191
Authors: S Imbert; M Palous; I Meyer; E Dannaoui; D Mazier; A Datry; A Fekkar Journal: Antimicrob Agents Chemother Date: 2014-09-08 Impact factor: 5.191
Authors: Carsten Schwarz; Dominik Hartl; Olaf Eickmeier; Andreas Hector; Christian Benden; Isabelle Durieu; Amparo Sole; Silvia Gartner; Carlos E Milla; Peter James Barry Journal: Mycopathologia Date: 2017-07-31 Impact factor: 2.574