Transposon-directed insertion site sequencing reveals glycolysis gene gpmA as part of the H2O2-defense mechanisms in E. coli

Hydrogen peroxide (H2O2) is a common effector of defense mechanisms against pathogenic infec-tions. 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 E. coli. The most interesting finding was the identification of gpmA, a gene involved in glycolysis, on the sensitivity of E. coli to H2O2. 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 cata-lase function and was independent of the carbon source or to the presence of oxygen. Transcrip-tion of gpmA was upregulated under H2O2 exposure, highlighting its role under oxidative stress. In summary, TraDIS approach identified gpmA as a member of the oxidative stress defense mechanism in E. coli.