Effect of nitric oxide donors on survival of conidia, germination and growth ofAspergillus fumigatus in vitro
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The effect of nitric oxide (NO) donors on survival of conidia, germination and growth of the opportunistic pathogenic fungusAspergillus fumigatus was investigated. Most efficient was sodium nitrite in an acidic milieu, (pH 4.5). At a concentration of 5 mmol/L it killed all resting conidia in buffer within 16 h. S-Nitroso derivatives of thiols (cysteine, N-acetylcysteine and N-acetylpenicillamine) at the same concentration killed about 30–50% of spores within 24 h. The NO scavenger, oxyhemoglobin, abolished these effects. S-Nitrosoglutathione had no fungicidal effect and promoted germination. Sodium nitrite and S-nitroso-N-acetylcysteine inhibited germination of conidia in various media from concentration of 0.5 mmol/L and stopped it at concentrations of 1.4–2.9 mmol/L. In media with glucose and casein hydrolyzate or sodium nitrate as nitrogen source, growth inhibition by sodium nitrite (0.5–2 mmol/L) was only weak and mostly transient. In general, the used strainA. fumigatus seems to be less sensitive to nitric oxide donors than dimorphic pathogenic fungi. Thus, nitric oxide is probably not a major effector molecule in killing phagocytized elements of this fungus by host's immunocytes.
KeywordsNitric Oxide Nitric Oxide Invasive Aspergillosis Sodium Nitrite Nitric Oxide Donor
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- Diamond R.D.: Invasive aspergillosis: Host defenses.Recent Results Canc. Res. (Germany)132, 109–115 (1993).Google Scholar
- Field L., Dilts R.V., Ravichandran R. Lenhert P.G., Carnahan G.E.: An unusually stable thionitrite from N-acetyl-d,l-penicillamine.J. Chem. Soc. Chem. Commun. 249–250 (1978).Google Scholar
- Gibson A., Babbedge R., Brave S.R., Hart S.L., Hobbs A.J., Tucker J.F., Wallace P., Moore P.K.: An investigation of some S-nitrosothiols, and of hydroxy-arginine, on the mouse anococcygeus.Brit. J. Pharmacol. 107, 715–721 (1992).Google Scholar
- Kowaluk E.A., Fung H.L.: Spontaneous liberation of nitric oxide, cannot account forin vitro relaxaton by S-nitrosothiols.J. Pharm. Exp. Ther. 255, 1256–1264 (1990).Google Scholar
- Radomski M.W., Rees D.D., Dutra A., Moncada S.: S-Nitrosoglutathione inhibits platelet activationin vitro andin vivo.Brit J. Pharmacol. 107, 745–749 (1992).Google Scholar
- Vanin A.F., Malenkova I.V., Mordvintsev O.I., Miul'sh A: Dinitrosyl complexes of iron with thiol-containing ligands and their conversion into nitrosothiols. (In Russian),Biokhimiya 58, 1094–1103 (1993).Google Scholar
- Washburn R.G.: Host defences against invasiveAspergillus infection; cited after Kappe R, Levitz S.M., Cassone A; Washburn R.G.: Mechanisms of host defence against fungal infection.J. Med. Vet., Mycol. 30 Suppl. 1, 167–177 (1992).Google Scholar