Tkachenko A G, Shumkov M S, Akhova A V
Mikrobiologiia. 2009 Jan-Feb;78(1):32-41.
Escherichia coli exposure to sublethal antibiotic concentrations induced an increase in cell polyamine contents. Maximum accumulation of putrescine and spermidine in response to antibiotics-induced oxidative stress preceded the increment of cadaverine, the content of which was dependent on the rpoS expression level and reached the maximum in response to fluoroquinolones. The polyamine positive modulating effects on rpoS expression increased in the following order: cadaverine-putrescine-spermidine. The reason for cadaverine accumulation was the increase in activities of lysine decarboxylases CadA and Ldc. High cadaverine accumulation in the cells exposed to fluoroquinolones and cephalosporins resulted in the reduction of porin permeability; so it was considered as a response aimed at cell protection against antibiotic penetration into the cell. Netilmycin, unlike other antibiotics, did not substantially affect the lysine decarboxylase activity and cellular polyamine pools.
大肠杆菌暴露于亚致死浓度的抗生素会导致细胞多胺含量增加。在抗生素诱导的氧化应激反应中，腐胺和亚精胺的最大积累先于尸胺的增加，尸胺的含量取决于rpoS的表达水平，并且在对氟喹诺酮类药物的反应中达到最大值。多胺对rpoS表达的正向调节作用按以下顺序增加：尸胺-腐胺-亚精胺。尸胺积累的原因是赖氨酸脱羧酶CadA和Ldc的活性增加。暴露于氟喹诺酮类药物和头孢菌素的细胞中高尸胺积累导致孔蛋白通透性降低；因此，这被认为是一种旨在保护细胞免受抗生素渗入细胞的反应。与其他抗生素不同，奈替米星对赖氨酸脱羧酶活性和细胞多胺库没有实质性影响。
