Department of Microbiology and Immunology, New York Medical College, Valhalla, NY.
Microbiol Spectr. 2015 Jun;3(3). doi: 10.1128/microbiolspec.MBP-0011-2014.
Borrelia burgdorferi, the spirochetal agent of Lyme disease, is a zoonotic pathogen that is maintained in a natural cycle that typically involves mammalian reservoir hosts and a tick vector of the Ixodes species. During each stage of the enzootic cycle, B. burgdorferi is exposed to environments that differ in temperature, pH, small molecules, and most important, nutrient sources. B. burgdorferi has a highly restricted metabolic capacity because it does not contain a tricarboxylic acid cycle, oxidative phosphorylation, or any pathways for de novo biosynthesis of carbohydrates, amino acids, or lipids. Thus, B. burgdorferi relies solely on glycolysis for ATP production and is completely dependent on the transport of nutrients and cofactors from extracellular sources. Herein, pathways for carbohydrate uptake and utilization in B. burgdorferi are described. Regulation of these pathways during the different phases of the enzootic cycle is discussed. In addition, a model for differential control of nutrient flux through the glycolytic pathway as the spirochete transits through the enzootic cycle is presented.
伯氏疏螺旋体，莱姆病的螺旋体病原体，是一种人畜共患病原体，存在于一个自然循环中，通常涉及哺乳动物储存宿主和硬蜱属的蜱媒介。在地方性循环的每个阶段，伯氏疏螺旋体都暴露在温度、pH 值、小分子和最重要的营养源不同的环境中。伯氏疏螺旋体的代谢能力受到高度限制，因为它不包含三羧酸循环、氧化磷酸化或从头合成碳水化合物、氨基酸或脂质的任何途径。因此，伯氏疏螺旋体仅依靠糖酵解产生 ATP，完全依赖于从细胞外来源运输营养物质和辅助因子。本文描述了伯氏疏螺旋体中碳水化合物摄取和利用的途径。讨论了在地方性循环的不同阶段这些途径的调节。此外，还提出了一种模型，用于控制螺旋体通过地方性循环时通过糖酵解途径的营养物质通量的差异。
