Metabolomic profiling can differentiate between bactericidal effects of free and polymer bound halogen

Abstract

The mechanism of bacterial cell death by the action of halogenated compounds is still 2 not clear. The aim of this research work is to use metabolomics to differentiate 3 between apparently dissimilar mechanisms of bacterial cell death by the action of 4 halogenated compounds. Two halogenated compounds (sodium hypochlorite and N-5 halamine polymers) were selected for this study and their effect was examined against 6Escherichia coli. Changes in the intracellular metabolite pools of bacterial cells 7 treated with different formulations of these compounds were analysed using FT-IR 8 spectroscopy and LC-MS. Principal component analysis (PCA) was used to generate 9 metabolic profiles. 10The study proved that the halogen containing compounds had an effect on the 11 bacterial intracellular metabolite profile. In addition, an effect was noticed for the 12 non-halogenated heterocyclic polymers. The mode of action of N-halamine polymer 13 is assumed to be a combination of contact, release and changes in the nature of the 14 medium around the cells. We think that the non-halogenated polymers may disturb 15 the ionic equilibrium between intra-and extra-cellular positive charges which result 16 in a deleterious effect on the bacteria cells. into the aqueous environment, in addition to direct contact between the solid polymer 6 material and the bacterial cells. Moreover, the metabolic profiles were able to 7 differentiate between the effect of free and polymer-bound halogen. Our metabolomic 8 approach was employed for hypothesis generation in order to distinguish apparently 9 different bactericidal effects of free and polymer-bound halogen. 10 11

New Approach To Produce Water Free of Bacteria, Viruses, and Halogens in a Recyclable System

“…Several mechanisms have been proposed to explain the halogen exchange between the N-halamine polymer and microorganisms. A widely held explanation is that protons of the amide functional groups of the protein sheet in the cell wall are oxidized by the halogen that has been gained from the polymer (6), but we have shown in a previous study that the N-halamine polymers can modify some of the bacterial metabolites, which may result in the cell's death (6).…”

“…The polymer (1.0 g) was soaked in sodium hypochlorite (10%, wt/wt; 15 ml) and 5 ml of distilled water overnight. The product was filtered, washed with 100 ml distilled water, and dried (6). The amount of halogen loaded on the polymer was determined by using iodometric titration, at 115 Ϯ 20 ppm (2,22).…”

“…In a previous study, we demonstrated the preparation of a commercial polymer, polymer 2 ( Fig. 1), with low cost (6). The aim of this study was to evaluate the biological activity of the halogenated form of this polymer, polymer 3 ( Fig.…”

“…m-Phenylenediamine (0.2 g; 10%, wt/wt) and sodium hydrogen carbonate (0.3 g) were added, and the reaction mixture was heated at 120°C for 24 h. Cyanuric acid (3.2 g; 0.025 mol) and sodium hydrogen carbonate (1.9 g) were added, and heating was continued for 24 h. The resulting gel was washed with hot water (80°C; 100 ml) to remove any cyanuric acid contaminating the polymer (Fig. 1) (6).…”

Applications of NMR spectroscopy based metabolomics: a review

“…Similarly, the methods of extraction, quenching, and sample storage conditions can affect and potentially modify metabolite structure, thereby confounding already complex data sets and introducing greater sample-to-sample variability. [22][23][24][25][26] NMR exploits the behavior of molecules when placed in a magnetic field, allowing the identification of different nuclei based on their resonant frequency. 20 Although MS is more sensitive than NMR, NMR spectroscopy has the advantages of being relatively robust across many samples, relatively fast in addition to being a non-destructive process.…”