Transposon-Directed Insertion-Site Sequencing Reveals Glycolysis Gene gpmA as Part of the H2O2 Defense Mechanisms in Escherichia coli

Abstract

Hydrogen peroxide (H2O2) is a common effector of defense mechanisms against pathogenic infections. However, bacterial factors involved in H2O2 tolerance remain unclear. Here we used transposon-directed insertion-site sequencing (TraDIS), a technique allowing the screening of the whole genome, to identify genes implicated in H2O2 tolerance in Escherichia coli. Our TraDIS analysis identified 10 mutants with fitness defect upon H2O2 exposure, among which previously H2O2-associated genes (oxyR, dps, dksA, rpoS, hfq and polA) and other genes with no known association with H2O2 tolerance in E. coli (corA, rbsR, nhaA and gpmA). This is the first description of the impact of gpmA, a gene involved in glycolysis, on the susceptibility of E. coli to H2O2. Indeed, confirmatory experiments showed that the deletion of gpmA led to a specific hypersensitivity to H2O2 comparable to the deletion of the major H2O2 scavenger gene katG. This hypersensitivity was not due to an alteration of catalase function and was independent of the carbon source or the presence of oxygen. Transcription of gpmA was upregulated under H2O2 exposure, highlighting its role under oxidative stress. In summary, our TraDIS approach identified gpmA as a member of the oxidative stress defense mechanism in E. coli.

Gre factors help Salmonella adapt to oxidative stress by improving transcription elongation and fidelity of metabolic genes

“…Although ΔgreAB Salmonella up-regulate glucose utilization upon oxidative stress, they lost much of their GAPDH activity following exposure to H 2 O 2 . Reduced GAPDH activity in ΔgreAB Salmonella likely limits carbon utilization through phosphoglycerate mutase GpmA, a glycolytic enzyme that is associated with the protective response of Salmonella and E. coli against oxidative stress [14,47].…”

The methylglyoxal pathway is a sink for glutathione in Salmonella experiencing oxidative stress

“…In summary, our investigations have revealed critical roles for the methylglyoxal pathway for both the utilization of glucose and resistance of Salmonella to oxidative stress emanating from the phagocyte NADPH oxidase. The methylglyoxal pathway must be added to the pentose phosphate pathway, glycolysis and fermentation as key metabolic adaptations of Salmonella to oxidative stress [20,21,[31][32][33].…”

Transposon mutagenesis screen inKlebsiella pneumoniaeidentifies genetic determinants required for growth in human urine and serum

“…To define the genetic basis of the K. pneumoniae urinome and serum resistome, we used Transposon Insertion Sequencing (TIS), also referred to as Transposon Directed Insertionsite Sequencing (TraDIS). TraDIS is a genome-wide screening technique that has been widely used to identify genes essential for bacterial growth and to discover conditionally essential genes under physiologically relevant conditions (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37). In this study, we generated a highly saturated transposon library within K. pneumoniae ECL8, a member of the K2-ST375 phylogenetic lineage that includes hypervirulent clones of epidemiological significance known to cause infections in relatively healthy subjects predominantly in Asia (38).…”