Anuchin Aleksey M, Mulyukin Andrey L, Suzina Natalya E, Duda Vitaly I, El-Registan Galina I, Kaprelyants Arseny S
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia.
Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.
Microbiology (Reading). 2009 Apr;155(Pt 4):1071-1079. doi: 10.1099/mic.0.023028-0.
Cultivation of Mycobacterium smegmatis cells in a nitrogen-limited minimal medium (SR-1) followed by prolonged storage at room temperature without shaking resulted in the gradual accumulation of morphologically distinct ovoid forms characterized by (i) low metabolic activity; (ii) elevated resistance to antibiotics and to heat treatment; and (iii) inability to produce colonies on standard agar plates (non-platable cells). Detailed microscopic examination confirmed that ovoid cells possessed an intact cell envelope, specific fine structure and large electron-transparent bodies in the cytoplasm. Cell staining with Nile red and analysis of the lipid content by TLC revealed the presence of significant amounts of apolar lipids in these bodies. The ovoid forms could be stored for significant periods (up to 5 months) and resuscitated afterwards in a modified Sauton's medium. Importantly, resuscitation of ovoid cells was accompanied by their transformation into the typical rod-shaped cells. We suggest that the observed ovoid cells represent dormant forms, resembling morphologically distinct cells of Mycobacterium tuberculosis previously isolated from tuberculosis patients and infected animals.
在限氮基本培养基（SR-1）中培养耻垢分枝杆菌细胞，随后在室温下不摇动长期保存，导致形态上不同的卵形细胞逐渐积累，其特征为：（i）代谢活性低；（ii）对抗生素和热处理的抗性增强；（iii）无法在标准琼脂平板上形成菌落（不可平板培养细胞）。详细的显微镜检查证实，卵形细胞具有完整的细胞膜、特定的精细结构以及细胞质中的大电子透明体。用尼罗红对细胞进行染色并通过薄层层析分析脂质含量，结果显示这些体内存在大量非极性脂质。卵形细胞可以保存很长时间（长达5个月），之后在改良的索顿培养基中复苏。重要的是，卵形细胞复苏时会转化为典型的杆状细胞。我们认为，观察到的卵形细胞代表休眠形式，在形态上类似于先前从结核病患者和受感染动物中分离出的结核分枝杆菌的不同细胞。
