Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou & Guizhou Talent Base for Microbiology and Human Health, Key Laboratory of Medical Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, China.
Center of Expertise in Mycology, Radboud University Medical Center/CWZ, Nijmegen, The Netherlands.
Mycoses. 2019 Sep;62(9):803-811. doi: 10.1111/myc.12931. Epub 2019 Jul 19.
Aureobasidium pullulans and A. melanogenum are black-yeast-like surface colonisers and are commonly encountered as contaminants in the hospital. The species are able to produce melanin which play a role in protection against environmental stress and irradiation. Aureobasidium melanogenum shows higher frequency in opportunistic infections compared to A. pullulans. Comparative pathogenicity of opportunistic black yeasts between Aureobasidium pullulans and A. melanogenum to explain the observed differences in frequency in infection. Degrees of melanisation and thermotolerance were measured, and virulence of strains from different sources was examined in Galleria mellonela and murine infection models. Aureobasidium melanogenum responds with increased melanisation to temperature stress and generally survives at 37°C, A. pullulans on average scored less on these parameters. In the murine model, differences between species were not significant, but the melanised A. melanogenum group showed the highest virulence. This result was not reproducible in Galleria mellonella larvae at 25°C. The A. melanogenum black group showed higher pathogenicity in murine model, indicating that the combination of melanisation and thermotolerance rather than species affiliation is instrumental. Galleria larvae did not survive very well at 37°C, and hence, this model is judged insufficient to detect the small virulence differences observed in Aureobasidium.
出芽短梗霉和暗绿青霉是黑色酵母样表面定植菌，常作为医院污染菌出现。这些物种能够产生黑色素，黑色素在抵御环境应激和辐射方面发挥作用。与出芽短梗霉相比，暗绿青霉在机会性感染中出现的频率更高。比较出芽短梗霉和暗绿青霉这两种机会性黑酵母的致病性，以解释观察到的感染频率差异。测量了黑色素化和耐热性程度，并在大蜡螟和鼠类感染模型中检查了来自不同来源的菌株的毒力。暗绿青霉对温度应激的反应是黑色素化增加，通常能在 37°C 下存活，而出芽短梗霉在这些参数上的平均得分较低。在鼠类模型中，种间差异不显著，但黑色素化的暗绿青霉组显示出最高的毒力。在 25°C 的大蜡螟幼虫中，这一结果无法重现。在鼠类模型中，暗绿青霉黑色组表现出更高的致病性，表明黑色素化和耐热性的结合而不是物种归属是起作用的。大蜡螟幼虫在 37°C 下不能很好地存活，因此，该模型被认为不足以检测到出芽短梗霉中观察到的微小毒力差异。
