Ciprofloxacin provokes SOS-dependent changes in respiration and membrane potential and causes alterations in the redox status of Escherichia coli

详细信息    查看全文

• 作者：Galina V. Smirnova^a ; ^{smirnova@iegm.ru} ; Aleksey V. Tyulenev^a ; ^{leksey333@yandex.ru} ; Nadezda G. Muzyka^a ; ^{muzyka@iegm.ru} ; Mikhail A. Peters^a ; ^{muxeu-mhz@mail.ru} ; Oleg N. Oktyabrsky^a ; ^b ; ^{oktyabr@iegm.ru}
• 关键词：Ciprofloxacin ; Respiration ; Membrane potential ; K+ efflux channels ; Glutathione ; Escherichia coli
• 刊名：Research in Microbiology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：168
• 期：1
• 页码：64-73
• 全文大小：987 K
• 卷排序：168

文摘

An in-depth understanding of the physiological response of bacteria to antibiotic-induced stress is needed for development of new approaches to combatting microbial infections. Fluoroquinolone ciprofloxacin causes phase alterations in Escherichia coli respiration and membrane potential that strongly depend on its concentration. Concentrations lower than the optimal bactericidal concentration (OBC) do not inhibit respiration during the first phase. A dose higher than the OBC provokes immediate SOS-independent inhibition of respiration and growth that can contribute to a decreased SOS response and lowered susceptibility to high concentrations of ciprofloxacin. Cells retain their metabolic activity, membrane potential and accelerated K+ uptake and produce low levels of superoxide and H2O2 during the first phase. The time before initiation of the second phase is inversely correlated with the ciprofloxacin concentration. The second phase is SOS-dependent and characterized by respiratory inhibition, membrane depolarization, K+ and glutathione leakage and cessation of glucose consumption and may be considered as cell death. atpA, gshA and kefBkefC knockouts, which perturb fluxes of protons and K+, can modify the degree and duration of respiratory inhibition and potassium retention. Loss of K+ efflux channels KefB and KefC enhances the susceptibility of E. coli to ciprofloxacin.