[Low-Molecular Thiols as a Factor Improving the Sensitivity of Escherichia coli Mutants with Impaired ADP-Heptose Synthesis to Antibiotics].

Low molecular-weight thiols as glutathione and cysteine are an important part of the cell's redox regulation system. Previously, we have shown that inactivation of ADP-heptose synthesis in Escherichia coli with a gmhA deletion induces the oxidative stress. It is accompanied by rearrangement of thiol homeostasis and increased sensitivity to antibiotics.

Enhancement of the Bactericidal Effect of Antibiotics by Inhibition of Enzymes Involved in Production of Hydrogen Sulfide in Bacteria.

Counteraction of the origin and distribution of multidrug-resistant pathogens responsible for intra-hospital infections is a worldwide issue in medicine. In this brief review, we discuss the results of our recent investigations, which argue that many antibiotics, along with inactivation of their traditional biochemical targets, can induce oxidative stress (ROS production), thus resulting in increased bactericidal efficiency. As we previously showed, hydrogen sulfide, which is produced in the cells of different pathogens protects them not only against oxidative stress but also against bactericidal antibiotics.

[Enhancement of the Bactericidal Effect of Antibiotics by Inhibition of Enzymes Involved in Production of Hydrogen Sulfide in Bacteria].

Counteraction of the origin and distribution of multidrug-resistant pathogens responsible for intra-hospital infections is a worldwide issue in medicine. In this brief review, we discuss the results of our recent investigations, which argue that many antibiotics, along with inactivation of their traditional biochemical targets, can induce oxidative stress (ROS production), thus resulting in increased bactericidal efficiency. As we previously showed, hydrogen sulfide, which is produced in the cells of different pathogens protects them not only against oxidative stress but also against bactericidal antibiotics.

[Inactivation of Terminal Oxidase bd-I Leads to Supersensitivity of E. coli to Quinolone and Beta-Lactam Antibiotics].

In cells of Escherichia coli, terminal oxidase bd-I encoded by the cydAB gene catalyzes the reduction of O2 to water using hydroquinone as an electron donor. In addition to the cydAB operon, two other genes, cydC and cydD, encoding the heterodimeric ATP-binding cassette-type transporter are essential for the assembly of cytochrome bd-I. It was shown that inactivation of cytochrome bd-I by the introduction of cydB or cydD deletions into the E.

Compressional wave velocity measurements on mafic-ultramafic rocks under high aqueous fluid pressure and temperature help to explain low-velocity zones in the lithosphere.

Deep seismic studies have revealed that low-velocity zones mainly occurred in the continental lithosphere at the depth of 100-150 km. Their origin has not been clearly explained yet. The article demonstrates the possible scale of Vp changes in crystalline rocks of different composition.