Transposon-Directed Insertion-Site Sequencing Reveals Glycolysis Gene as Part of the HO Defense Mechanisms in .

Hydrogen peroxide (HO) is a common effector of defense mechanisms against pathogenic infections. However, bacterial factors involved in HO 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 HO tolerance in . Our TraDIS analysis identified 10 mutants with fitness defect upon HO exposure, among which previously HO-associated genes (, , , , and ) and other genes with no known association with HO tolerance in (, , and ). This is the first description of the impact of , a gene involved in glycolysis, on the susceptibility of to HO. Indeed, confirmatory experiments showed that the deletion of led to a specific hypersensitivity to HO comparable to the deletion of the major HO scavenger gene . 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 was upregulated under HO exposure, highlighting its role under oxidative stress. In summary, our TraDIS approach identified as a member of the oxidative stress defense mechanism in .