Overview of SPA-S-843 in vitro activity against filamentous fungi

In this study, we investigated the in vitro antifungal activity of a new wa ter-soluble partricin A derivative, N-dimethylaminoacetyl-partricin A 2-dim ethylaminoethylamide diascorbate, coded SPA-843, currently developed by Soc ieta Prodotti Antibiotici. The activity of SPA-S-843 was compared to that o f amphotericin B against 13 strains of Aspergillus spp., 4 strains of Mucor sp., 4 strains of Rhizopus oryzae, 2 strains Paecilomyces variotii, 5 stra ins of Penicillium spp., 1 strain of Sporothrix schenkii, 7 strains of Tric hophyton spp. and 2 strains of Microsporum spp.; the minimum inhibitory con centrations (MICs) and minimum fungicidal concentrations (MFCs) were measur ed for all the organisms. The in vitro susceptibility testing method employ ed was an adaptation of the macrodilution reference method for yeasts as de scribed in the National Committee for Clinical Laboratory Standards documen t M27-A. The in vitro inhibitory activities of SPA-S-843 and amphotericin B against the fungi were evaluated in RPMI-1640 supplemented with L-glutamin e and buffered with morpholine-propanesulfonic acid, while the in vitro fun gicidal activities were determined by subculturing 0.1 ml from all tubes wi th no visible growth onto drug-free Sabouraud dextrose agar plates. Compari son with amphotericin B showed that the in vitro inhibitory activity of SPA -S-843 against Aspergillus spp. was better than that of amphotericin B and similar against R. oryzae, P. variotii, Penicillium spp. and S. schenkii. A mphotericin B presented geometric means (GM) of the MICs lower than those o f SPA-S-843 against Mucor sp., Microsporum spp. and Trichophyton spp. SPA-S -843 was most fungicidal against Mucorsp. and P. variotii; SPA-S-843 and am photericin B showed the same fungicidal activity against Aspergillus sop, ( GM of the MFCs 12.53 mu g/ml), Penicillium spp, (about 12 mu g/ml) and S. s chenkii (MFC 19.2 mu g/ml). Amphotericin B presented GM of the MFC values l ower than those of SPA-S-843 against R. oryzae, Microsporum sop, and Tricho phyton sop. Copyright (C) 2000 S. Karger AG, Basel.