Kunert J
Department of Biology, Palacký University, Olomouc, Czech Republic.
Folia Microbiol (Praha). 1995;40(3):238-44. doi: 10.1007/BF02814199.
The effect of nitric oxide (NO) donors on survival of conidia, germination and growth of the opportunistic pathogenic fungus Aspergillus 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 strain A. 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.
研究了一氧化氮（NO）供体对机会致病性真菌烟曲霉分生孢子存活、萌发和生长的影响。在酸性环境（pH 4.5）中，亚硝酸钠的效果最为显著。浓度为5 mmol/L时，它能在16小时内杀死缓冲液中所有静止的分生孢子。相同浓度的硫醇（半胱氨酸、N - 乙酰半胱氨酸和N - 乙酰青霉胺）的S - 亚硝基衍生物在24小时内杀死约30 - 50%的孢子。NO清除剂氧合血红蛋白消除了这些作用。S - 亚硝基谷胱甘肽没有杀菌作用，反而促进了孢子萌发。亚硝酸钠和S - 亚硝基 - N - 乙酰半胱氨酸在浓度为0.5 mmol/L时就能抑制各种培养基中分生孢子的萌发，并在浓度为1.4 - 2.9 mmol/L时完全阻止萌发。在以葡萄糖和酪蛋白水解物或硝酸钠作为氮源的培养基中，亚硝酸钠（0.5 - 2 mmol/L）对生长的抑制作用较弱且大多是短暂的。总体而言，所用的烟曲霉菌株似乎对NO供体的敏感性低于双相致病性真菌。因此，一氧化氮可能不是宿主免疫细胞杀死该真菌吞噬成分的主要效应分子。
