Abstract

A potential method for the destruction of dormant Mycobacteriumsmegmatis (Msm) mycobacteria via photodynamic inactivation (PDI) using their ability to store endogenous porphyrins during the transition to a dormant state was studied. The dormant Msm cells were obtained under gradual acidification of the growth medium in the stationary phase for 14 days at different concentrations of ferric ions and the presence of 5-aminolevulinic acid in the growth medium. Cells were exposed to light at a wavelength of 532 nm emitted by an LLD10 laser for 5–60 min. It was shown that an increase in the coproporphyrin concentration in M. smegmatis after 6 days of growth correlated with the onset of a decrease in metabolic activity in cells and the formation of ovoid dormant forms. The dormant bacteria were sensitive to PDI and were destroyed after 15–30 min of illumination, in contrast to active cells. In the presence of 5-aminolevulinic acid and an optimal concentration of ferric ions (0.5 mg/L), there was an increase in the production of uroporphyrin in both active and dormant mycobacteria, which was accompanied by an increase in sensitivity to the action of PDI. The results demonstrate the promise of PDI for the destruction of dormant mycobacteria and the fight against latent tuberculosis.

中文翻译：

---

光动力灭活对耻垢分枝杆菌的休眠形式和活跃生长细胞的影响

摘要

研究了一种潜在的方法，该方法通过利用光动力灭活（PDI）在过渡到休眠状态期间存储内生卟啉的能力来破坏耻垢分枝杆菌（Msm）分枝杆菌。在不同浓度的铁离子和生长培养基中存在5-氨基乙酰丙酸的条件下，在固定相中生长培养基逐渐酸化14天后获得休眠的Msm细胞。将细胞暴露于LLD10激光发出的532 nm波长的光下5-60分钟。结果表明，耻垢分枝杆菌中原卟啉的浓度增加生长6天后的生长与细胞代谢活性降低的开始和卵形休眠形式的形成有关。与活动细胞相反，休眠细菌对PDI敏感，在光照15-30分钟后被破坏。在存在5-氨基乙酰丙酸和最适浓度的铁离子（0.5 mg / L）的情况下，活性和休眠分枝杆菌中尿卟啉的产量均增加，同时伴随着对氨基苯甲酸作用的敏感性增加。 PDI。结果表明，PDI有望销毁休眠的分枝杆菌并与潜在的结核病作斗争。