Study of Linkage between Glutathione Pathway and the Antibiotic Resistance of Escherichia coli from Patients’ Swabs

Abstract

In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (γ-glutamylcysteine synthase—GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the determined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 µM), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of “more resistant” E. coli exhibited differences in Km between 0.3 and 0.8 µM. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group.

Co-delivery of VP-16 and Bcl-2-targeted antisense on PEG-grafted oMWCNTs for synergistic in vitro anti-cancer effects in non-small and small cell lung cancer

“…The resulting oxygen-containing functionalities are crucial for the enhancement of interfacial adhesion of grafted polymers [29]. Indeed, our preliminary results illustrated that oMWCNTs-PEG can accommodate a significantly higher amount of VP-16, compared to the nonPEGylated oMWCNTs [19]. Our results also revealed excellent sustained release profiles, characterized by a slower slope, indicating that oMWCNTs-PEG were able to overcome the burst effect of free VP-16.…”

“…The conjugates were prepared as described in our previous study [19]. Briefly, 2 mg of MWCNTs (Sigma Aldrich, St. Louis, MO, USA) were oxidized using 1 mL of 68% HNO 3 (Sigma Aldrich, MO, USA) in aqueous solution (w/w).…”

“…The amount of reduced glutathione (GSH) was determined using high-performance liquid chromatography coupled with an electrochemical detector (HPLC-ED) under the conditions employed in our previous study [19].…”

“…After synthesis, the supernatant was discarded by centrifugation (10 000 × g at 20 • C for 10 min) and the amount of the present VP-16 or phoshorothioate deoxyoligonucleotides was examined using multifunctional microplate reader Tecan Infinite 200 PRO (Tecan, Männedorf, Switzerland) at exc 250 nm and em 320 nm and square wave voltammetry according to our previous study [19]. The drug loading was calculated according to Datir et al [20].…”

Exposure to 17β-Oestradiol Induces Oxidative Stress in the Non-Oestrogen Receptor Invertebrate Species Eisenia fetida

“…The antioxidant molecule contents were determined using high performance liquid chromatography coupled with an electrochemical detector (HPLC-ED) as previously described for the analyses of GSH/GSSG [ 42 ] and PCs [ 43 ].…”