TABLE 2.

Synergy activity of HMA with azole antifungal drugs against strains of Cryptococcus: Cryptococcus neoformans H99, Cryptococcus neoformans JEC21, and Cryptococcus gattii.

	Cryptococcus neoformans H99			Cryptococcus neoformans JEC21			Cryptococcus gattii NIH444
Drug	MIC (i)	MIC (t)	FIC	MIC (i)	MIC (t)	FIC	MIC (i)	MIC (t)	FIC
HMA	64	16	0.50	32	8	0.50	64	8	0.63
Flue	4	1		2	0.5		2	1
HMA	64	1	0.27	32	4	0.38	32	2	0.13
Itra	0.25	0.063		0.25	0.063		4	0.25
HMA	32	8	0.50	64	16	0.37	64	16	0.38
Keto	0.125	0.031		0.125	0.016		0.5	0.063
HMA	32	4	0.25	64	16	0.28	64	32	0.62
Posa	0.125	0.016		0.25	0.008		0.125	0.016
HMA	32	2	0.13	32	4	0.19	32	8	0.31
Ravu	0.063	0.004		0.125	0.008		0.125	0.008
HMA	32	2	0.31	32	8	0.50	64	8	0.37
Vori	0.063	0.016		0.031	0.008		0.063	0.016

MIC(t) MIC (μg/ml) of drugs together; MIC(i), MIC (μg/ml) of individual drug; FIC, fractional inhibitory concentration. Drug interactions were based on ΣFIC indices and classified as synergistic (Σ FIC < 0.5), additive (Σ FIC = 0.5 through 1), indifferent (Σ FIC = 1 through 4), or antagonistic (Σ FIC > 4). Fluc, fluconazole; Itra, itraconazole; Keto, ketoconazole; Posa, posaconazole; Ravu, ravueonazole; Vori, voriconazole. HMA, 5-(N,N-Hexamethylene)amiloride. Susceptibility assays were repeated atleast three times.