Understanding the physiological processes underlying the ability of Mycobacterium abscessus to become a chronic pathogen of the cystic fibrosis (CF) lung is important to the development of prophylactic and therapeutic strategies to better control and treat pulmonary infections caused by these bacteria. Gene expression profiling of a diversity of M. abscessus complex isolates points to amino acids being significant sources of carbon and energy for M. abscessus in both CF sputum and synthetic CF medium and to the bacterium undergoing an important metabolic reprogramming in order to adapt to this particular nutritional environment. Cell envelope analyses conducted on the same representative isolates further revealed unexpected structural alterations in major cell surface glycolipids known as the glycopeptidolipids (GPLs). Besides showing an increase in triglycosylated forms of these lipids, CF sputum- and synthetic CF medium-grown isolates presented as yet unknown forms of GPLs representing as much as 10% to 20% of the total GPL content of the cells, in which the classical amino alcohol located at the carboxy terminal of the peptide, alaninol, is replaced with the branched-chain amino alcohol leucinol. Importantly, both these lipid changes were exacerbated by the presence of mucin in the culture medium. Collectively, our results reveal potential new drug targets against M. abscessus in the CF airway and point to mucin as an important host signal modulating the cell surface composition of this pathogen.

中文翻译：

---

囊性纤维化气道生长条件下脓肿分枝杆菌的细胞表面重塑。

了解脓肿分枝杆菌成为肺囊性纤维化（CF）慢性病原体能力的生理过程，对于制定预防和治疗策略以更好地控制和治疗由这些细菌引起的肺部感染至关重要。脓肿支原体复合体多样性的基因表达谱表明氨基酸是脓肿支原体的重要碳和能量来源在CF痰和合成CF培养基中都存在，并且对细菌进行重要的代谢重编程以适应这种特殊的营养环境。在相同的代表性分离物上进行的细胞包膜分析进一步揭示了在主要细胞表面糖脂（称为糖肽脂质（GPL））中的意外结构改变。除了显示出这些脂质的三糖基化形式增加外，CF痰和合成CF培养基中生长的分离株还表现出未知的GPL形式，占细胞总GPL含量的10％至20％。位于肽羧基末端的氨基醇丙氨醇被支链氨基醇亮氨酸取代。重要的是，培养基中粘蛋白的存在会加剧这两种脂质的变化。CF气道中的脓肿分支杆菌将黏蛋白作为调节该病原体细胞表面组成的重要宿主信号。