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Creation of synergistic combinations of antifungal and antiseptic agents can be considered as one of the promising strategies for reducing the spread of drug resistance in pathogenic fungi.Aim. The aim of this work was to study the synergistic antifungal activity of amphotericin B (AMB) and antiseptic miramistin (MST) in their combined use to fight against drug-resistant Candida isolates. Material and methods. One AMB-resistant C.albicans strain (MIC 3.1 µg/ml), sensitive to MST, two isolates of C.albicans with different level of resistance to MST and AMB (MIC 1.6–6.3 µg/ml), and one MST-resistant C.lusitaniae isolate susceptible to AMB (MIC 0.4 µg/ml) were studied. Isolates’ susceptibility to AMB and MST alone was determined by broth microdilution method and time–kill assay, respectively. Individual anti-candida activity of test combinations of 0.001% MST with AMB in 10 or 50 µg/ml concentrations was studied using quantitative time–kill assay.Results. A significant decrease in the growth of all the isolates treated with both test combinations of MST and AMB in comparison with individual medication treatment was observed at each time interval studied (15–60 minutes). As part of the combination, MST exhibited significant synergy with AMB in sublethal concentration of 10 µg/ml against all the isolates. Treatment of the fungi with a combination of MST with AMB in 50 µg/ml concentration caused complete inactivation of all the isolates after 30 minutes. Under these conditions, AMB exhibited separate antifungal activity.Conclusion. These findings suggest the possible effective use of miramistin in combination with amphotericin B against multi-drug resistant isolates of the genus Candida.

Triterpene saponin Taurosid Sx1 purified from leaves of the plant Crimean Ivy Hedera taurica Carr. (Araliaceae) was evaluated for its cytotoxic activity against lymphoblastoid cell lines MT-4, Jurkat-tat, U937, and human peripheral blood monocytes. The ability of saponin to influence HIV-1 replication was studied as well. In addition, the ability of Taurosid Sx1 to increase survival of mice infected with influenza virus А/WSN/1/33(H1N1) and its capacity for strengthening the immune responses in mice immunized with the influenza vaccine Grippol® have been studied. Taurosid Sx1 has been shown to inhibit MT-4 cell line at 25 μg ml-1 concentration, IC50 33,3 μmol l-1 (MTT assay). The saponin concentration of 5 μg ml-1 was non-toxic for all the cell lines studied and demonstrated a moderate inhibitory effect on HIV p24 production in Jurkat-tat cells. In the lower concentrations Taurosid Sx1 did not stimulate HIV p24 production. It was shown that oral administration of 200 μg Taurosid Sx1 to the influenza virus infected mice caused 1.5-fold increase in their survival. Taurosid Sx1 given orally amplified immunopotentiating ability of an intramusculary administered subunit influenza vaccine. Antibody production was significantly higher in animals fed Taurosid Sx1 after primary or secondary immunizatuion. In mice given 2 doses of vaccine, from 1 to 3 weeks apart, feeding 200 μg saponin resulted in 2 to 10-fold enhancement in production of anti-H1, anti-H3, and anti-inluenza type B hemagglutinin antibodies. Thus, Taurosid Sx1 can be considered as low-toxic promising immunopotentiating agent uncapable of enhancing HIV-1 replication.