Work

Iron-sulfur cluster proteins present the weak spot in non-thermal plasma-treated Escherichia coli

Year: 2025

Type: article

Abstract: Non-thermal atmospheric pressure plasmas have an antiseptic activity beneficial in different medical applications. In a genome-wide screening, hydrogen peroxide and superoxide were identified as key species contributing to the antibacterial effects of plasma while [FeS] cluster proteins emerged as potential cellular targets. We investigated the impact of plasma treatment on [FeS] cluster homeostasis in Escherichia coli treated for 1 min with the effluent of a microscale atmospheric pressure plasma jet (μAPPJ). Mutants defective in [FeS] cluster synthesis and maintenance lacking the SufBC 2 D scaffold protein complex or desulfurase IscS were hypersensitive to plasma treatment. Monitoring the activity of [FeS] cluster proteins of the tricarboxylic acid cycle (aconitase, fumarase, succinate dehydrogenase) and malate dehydrogenase (no [FeS] clusters), we identified cysteine, iron, superoxide dismutase, and catalase as determinants of plasma sensitivity. Survival rates, enzyme activity, and restoration of enzyme activity after plasma treatment were superior in mutants with elevated cysteine levels and in the wildtype under iron replete conditions. Mutants with elevated hydrogen peroxide and superoxide detoxification capacity over-expressing sodA and katE showed full protection from plasma-induced enzyme inactivation and survival rates increased from 34 % (controls) to 87 %. Our study indicates that metabolic and genetic adaptation of bacteria may result in plasma tolerance and resistance, respectively. • Enzymes with [FeS] clusters are rapidly inactivated by plasma. • Clusters damaged by plasma are repaired in vivo using iron and cysteine. • Over-expression of sodA and katE completely prevents disruption of [FeS] clusters by plasma. • Plasma resistance is increased threefold by SodA and KatE over-production. • Pre-adaptation of E. coli to O 2 − increases plasma tolerance.

Source: Redox Biology

DOI: 10.1016/j.redox.2025.103562

Authors: Marco Krewing, Kim Marie Weisgerber, Tim Dirks, Ivan Bobkov, Britta Schubert, Julia Elisabeth Bandow

Institution: Ruhr University Bochum

Language: English

Topic: Plasma Applications and Diagnostics

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $4,310