The stress response of Listeria monocytogenes inoculated on fresh apples exposed to gaseous chlorine dioxide

AbstractFresh apples are vulnerable to Listeria monocytogenes (L. monocytogenes) contamination during handling and storage causing subsequent foodborne outbreaks. Gaseous chlorine dioxide (ClO2) is an effective antimicrobial agent against L. monocytogenes and could augment food safety. This study investigates the stress and virulence response of L. monocytogenes on apples exposed to a sublethal concentration of ClO2. L. monocytogenes was inoculated on the surface of apples and exposed to gaseous ClO2 for 1 h. Gene expression analysis via Real‐Time quantitative polymerase chain reaction (RT‐qPCR) revealed minimal changes in gene expression compared to control samples. However, a surface‐dependent response was observed, with slight upregulation of relevant virulence (hly) and stress (clpC) genes on more hydrophilic surfaces. These findings indicate that gaseous ClO2 treatment can provide a biostatic effect against L. monocytogenes on fresh produce, shedding light on its antimicrobial mechanism and potential for enhancing apple safety.