Electron microscopy study revealed changes in the ultrastructure of bacteria of Yersinia pseudotuberculosis strains characterized by significantly reduced reproductive ability and virulence potential after long-term storage at low temperature of 4-8°C. Most bacterial cells contained dark cytosol with reduced cellular material or empty cytosol, while the cell wall was preserved. The revealed ultrastructural changes in the bacterial cells of the static culture of Y. pseudotuberculosis suggest that storage of strains under low positive temperatures could induce the transition of the majority of bacterial cell population to a dormant, non-cultivated state with a decrease in their virulence. This fact is of great scientific and applied importance in studies of causative agents of saprozoonoses, including pseudotuberculosis, which has the etiopathogenetic background of persistent infection.

中文翻译：

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低温条件下长期保存假结核耶尔森菌静态培养物中细菌超微结构的变化

电子显微镜研究显示，假结核耶尔森氏菌菌株的细菌超微结构发生变化，其特征是在 4-8°C 的低温下长期储存后繁殖能力和毒力显着降低。大多数细菌细胞含有黑色细胞质，细胞物质减少或空细胞质，而细胞壁被保留。假结核耶尔森菌静态培养的细菌细胞超微结构变化表明，在低正温度下储存菌株可以诱导大多数细菌细胞群转变为休眠、非培养状态，并降低其毒力. 这一事实在研究包括假结核在内的人畜共患病病原体研究中具有重要的科学和应用意义。