Transcriptomic and proteomic analysis of the effect of hydrogen peroxide on enterohemorrhagic Escherichia coli

Enterohemorrhagic Escherichia coli (EHEC) is an emerging pathogen responsible for causing severe gastrointestinal infections in humans through foodborne transmission. Previous research has demonstrated that oxidative stress can lead to the increased expression of the Shiga toxin, which serves as the primary virulence factor in EHEC. This study used transcriptomic and proteomic analyses to generate a holistic view on the response EHEC O157:H7 strain EDL933 of oxidative stress induced by exposure to hydrogen peroxide, and its implications on the pathogenesis and survival of this bacterium. The results showed that exposing EHEC to oxidative stress triggers expression of a complex array of enzymatic and non-enzymatic defense mechanisms, that counteracts the detrimental effects of oxidative stress and contributes to its robustness and adaptability in a hostile environment. Oxidative stress also affects expression of a wide array of chromosomally-, phage and plasmid-encoded virulence-associated traits, including Stx1 and Stx2 and adhesion-associated factors. The results can be used as a foundation for further investigations into the specific mechanisms and regulatory interactions involved in EHEC's response to oxidative stress. This work enhances our understanding of EHEC O157:H7 pathogenesis and can aid in the development of novel therapeutic interventions and preventive strategies against EHEC infections. • Hydrogen peroxide treatment leads to changes in expression of 41 % of EHECs genes. • Hydrogen peroxide treatment strongly impacts EHEC's iron acquisition genes. • H 2 O 2 exposure alters ribosomal gene and protein expression, impacting stress responses and growth phases. • H 2 O 2 treatment boosts expression of flagellar and chemotaxis genes. • H 2 O 2 influences EHEC virulence factors such as T3SS and plasmid pO157.